CN102611822B - Projector and projection image rectifying method thereof - Google Patents

Abstract

The invention discloses a projector and a projection image rectifying method thereof. The projection image rectifying method includes: taking images of a projection area projected on a display screen by the projector through a taking module and obtaining images; determining corresponding geometric rectifying parameters by a rectifying module according to the projection area in the pictures; computing and converting original images to be projected by utilizing geometric rectifying parameters to obtain rectified images; and projecting the rectified images onto the display screen by the projection module. By analyzing the projection area in the images to perform geometric rectifying process or color rectifying process, so that rectifying operation can be realized without preset images with certain features, and process of rectifying projection images is simplified.

Description

Projecting apparatus and projected picture correcting method thereof

Technical field

The present invention relates to shadow casting technique, particularly relate to equipment and method that projected image is corrected.

Background technology

Projecting apparatus is a kind of projection arrangement being used for amplifying display image on screen, has been widely used at present in demonstration and home theater.Such as, demonstrate for meeting room and on large-screen, watch film by connecting the equipment such as DVD player in the family.

If the optical axis of projecting apparatus and screen surface out of plumb, namely become an angle of inclination with screen surface, then the image that screen surface shows can be caused to distort.In order to correct fault image, can, by the screw under projecting apparatus seat, regulate projecting apparatus at the inclination angle in horizontal and vertical direction, with correcting orthographic projection image.Can this manual adjustment mode, projecting apparatus is used very inconvenient.

For this reason, provide a kind of projecting apparatus with automatic calibration projected image function in prior art, as shown in Figure 1, comprising: correcting unit, projecting cell, angular transducer unit.Angular transducer unit in projecting apparatus calculates the angle of inclination of projected image in horizontal and vertical direction automatically, the angle of inclination in the horizontal and vertical direction that correcting unit calculates according to angular transducer unit, is corrected projected image by projecting cell.The complicated part of this method is: angular transducer unit is made up of range sensor and angle calculation unit, range sensor needs to obtain the distance of multiple measurement point distance projecting apparatus in screen surface, thus angle calculation unit calculates the angle of inclination in horizontal and vertical direction according to the distance measured.In order to obtain the distance of multiple measurement point distance projecting apparatus in screen surface, then need predetermined image projection on screen.Further, the method, owing to being provided with angular transducer in projecting apparatus, also has higher hardware cost.

In addition, the another kind of projecting apparatus being provided with camera in prior art, can utilize camera to take projected image to realize the correction of projected image.But the auto-correction method of these projecting apparatus also needs in the process corrected at present, and project some predetermined special images.Such as, predetermined special image can be one group of picture with edge feature: background is black, evenly distributed along image edge with the spherical dot matrix of white.After predetermined image is projected to screen surface, camera shooting projected image, and calculate distortion according to edge feature, and correct on this basis.Although the method does not need built-in angular transducer, reduces hardware cost, in trimming process, still need the predetermined image that projects, make trimming process comparatively complicated.

In sum, can realize the projecting apparatus of automatic calibration projected image at present, carrying out all needing some predetermined images that project in projection image correction process, this makes trimming process more loaded down with trivial details.Further, after completing correction, in the process of carrying out normal projection, in the event of projected image distortion, then due to the predetermined image that cannot project, projecting apparatus can not identify the projected image of distortion automatically, also just cannot automatically again correct, unless carried out manual intervention.Namely the projecting apparatus of the automatic calibration projected image of prior art can not realize real-time automatic calibration projected image.

Summary of the invention

Embodiments provide a kind of projecting apparatus and projected picture correcting method thereof, in order to simplify the method for automatic calibration projected image.

According to an aspect of the present invention, provide a kind of projected picture correcting method, comprising: by photographing module, the view field that projecting apparatus projects on the display screen is taken, obtain photographic images; After correction module receives described photographic images, according to the view field in described photographic images, determine corresponding geometric correction parameter; And use described geometric correction parameter to make operation transform to needing the original image of projection, obtain the image after correcting; By projection module by the image projection after described correction on display screen.

Preferably, described correction module, according to the view field in described photographic images, determines that corresponding geometric correction parameter is specially: described correction module, according to the position coordinates on four of described view field summits, determines corresponding geometric correction parameter.

Preferably, the position coordinates on described four summits according to described view field, determines corresponding geometric correction parameter, comprising: according to the position coordinates on four summits of described view field, and the position coordinates on four summits of correction rectangle, calculate geometric correction parameter.

Preferably, the position coordinates on described four summits according to described view field, and the position coordinates on four summits of correction rectangle, calculate geometric correction parameter specifically according to following formula:

$\left[\begin{array}{c}{x_i}^{\′}\\ {y_i}^{\′}\end{array}\right]=\frac{\left[\begin{array}{cc}a& b\\ c& d\end{array}\right]\left[\begin{array}{c}{x}_i\\ y_i\end{array}\right]+\left[\begin{array}{c}e\\ f\end{array}\right]}{1+\left[\mathrm{u\; v}\right]\left[\begin{array}{c}{x}_i\\ y_i\end{array}\right]}$ (formula 1)

Wherein, i is the integer between [Isosorbide-5-Nitrae], (x ₁, y ₁), (x ₂, y ₂), (x ₃, y ₃), (x ₄, y ₄) be the position coordinates on four summits of described view field; (x ₁', y ₁'), (x ₂', y ₂'), (x ₃', y ₃'), (x ₄' y ₄') be the position coordinates on four summits of described correction rectangle; A, b, c, d, e, f, u, v are the geometric correction parameter calculated.

Preferably, the described geometric correction parameter of described use makes operation transform to needing the original image of projection, obtains the image after correcting, comprising:

If if (x, y) is the position coordinates of the pixel in original image, then according to following formula:

$\left[\begin{array}{c}{x}^{\′}\\ y^{\′}\end{array}\right]=\frac{\left[\begin{array}{cc}a& b\\ c& d\end{array}\right]\left[\begin{array}{c}x\\ y\end{array}\right]+\left[\begin{array}{c}e\\ f\end{array}\right]}{1+\left[\mathrm{u\; v}\right]\left[\begin{array}{c}x\\ y\end{array}\right]}$ (formula 2)

Determine the position coordinates (x ', y ') of respective pixel in the image after correction.

Wherein, the position coordinates on four summits of described correction rectangle is predefined; Or the position coordinates on four summits of described correction rectangle determines according to the position coordinates on four summits of view field in described photographic images.

The position coordinates on four summits of described correction rectangle determines to comprise according to the position coordinates on four summits of view field in described photographic images: for the quadrangle be made up of four summits of view field in described photographic images, determines that the position coordinates on four summits of described correction rectangle is positioned within described quadrangle; Or, for the described quadrangle be made up of four summits of view field in described photographic images, determine that the position coordinates on four summits of described correction rectangle is positioned within described quadrangle, and the ratio of width to height of described correction rectangle is identical with the ratio of width to height of described original image.

Further, by photographing module, the view field that projecting apparatus projects on the display screen is being taken, after obtaining photographic images, also comprise: authentication module carries out geometric distortion judgement to view field in described photographic images, and geometric distortion judged result is sent to described correction module; And, described correction module is after determining the view field in described photographic images, determine corresponding geometric correction parameter, be specially: described correction module is after determining that described geometric distortion judged result is distortion, determine the view field in described photographic images, and determine corresponding geometric correction parameter.

Further, by photographing module, the view field that projecting apparatus projects on the display screen is being taken, after obtaining photographic images, also comprise: a, correction module, according to the relative position between the chromaticity coordinates of the background colour of the view field in the photographic images of the current acquisition of described photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system, determine primary colours to be adjusted; And the brightness adjustment value of the primary colours to be adjusted determined is sent to described projection module; Described brightness adjustment value is predetermined; B, described projection module are according to the brightness of the corresponding primary colours of the brightness adjustment value adjustment light source of described primary colours to be adjusted; C, correction module continue the photographic images obtaining described photographing module current shooting, and the relative distance between the chromaticity coordinates of the background colour of view field in the photographic images determining the current acquisition of described photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system is when being less than set point, terminate this time to correct; Otherwise, repeat step a, b, c.

Further, by photographing module, the view field that projecting apparatus projects on the display screen is being taken, after obtaining photographic images, also comprise: authentication module carries out cross-color judgement to view field in described photographic images, and cross-color judged result is sent to described correction module; And, correction module is according to the relative position between the chromaticity coordinates of the background colour of the view field in the photographic images of the current acquisition of described photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system, determine that primary colours to be adjusted are specially: described correction module is after determining that described cross-color judged result is distortion, according to the relative position between chromaticity coordinates in hue coordinate system of the background colour of the view field in the photographic images of the current acquisition of described photographing module and the chromaticity coordinates of object color component in hue coordinate system, determine primary colours to be adjusted.

Wherein, described authentication module carries out cross-color to view field in described photographic images and judges to comprise: if described authentication module determines that the distance between the chromaticity coordinates of the background colour of the view field in the photographic images of the current acquisition of described photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system exceedes setpoint distance value, then determine that described cross-color judged result is distortion; Otherwise, determine that described cross-color judged result is undistorted.

Described correction module is according to the relative position between the chromaticity coordinates of the background colour of the view field in the photographic images of the current acquisition of described photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system, determine that primary colours to be adjusted comprise: establish the chromaticity coordinates of three primary light source to be respectively R, G, B point in described hue coordinate system, the chromaticity coordinates of described object color component is W point in hue coordinate system, and the chromaticity coordinates of the background colour of the view field in the photographic images of the current acquisition of described photographing module is T point in hue coordinate system; Straight line RW, GW, BW cross straight line BG, BR, GR respectively in some P, N, M, triangle RGB are divided into the little triangle of GWM, BWN, GWP, RWN, RWM, BWP; If T point is positioned at little triangle GWM or BWN, then determine that primary colours to be adjusted are R primary colours, and the brightness adjustment value of R primary colours be on the occasion of; If T point is positioned at little triangle GWP or RWN, then determine that primary colours to be adjusted are B primary colours, and the brightness adjustment value of B primary colours be on the occasion of; If T point is positioned at little triangle RWM or BWP, then determine that primary colours to be adjusted are G primary colours, and the brightness adjustment value of G primary colours be on the occasion of; If T point overlaps with the extended line of BW line segment or is less than setting threshold, then determine that primary colours to be adjusted are B primary colours, and the brightness adjustment value of B primary colours be on the occasion of; If T point overlaps with the extended line of RW line segment or is less than setting threshold, then determine that primary colours to be adjusted are R primary colours, and the brightness adjustment value of R primary colours be on the occasion of; If T point overlaps with the extended line of GW line segment or is less than setting threshold, then determine that primary colours to be adjusted are G primary colours, and the brightness adjustment value of G primary colours be on the occasion of.

According to another aspect of the present invention, additionally provide a projecting apparatus, comprising: photographing module, take for the view field projected on the display screen projecting apparatus, obtain photographic images; Correction module, for according to the view field in described photographic images, determines corresponding geometric correction parameter; And use described geometric correction parameter to make operation transform to needing the original image of projection, obtain the image after correcting; Projection module, for by the image projection after described correction to display screen.

Preferably, described correction module is used for according to the view field in described photographic images, determine that corresponding geometric correction parameter comprises: according to the position coordinates on four summits of described view field, and the position coordinates on four summits of correction rectangle, calculate geometric correction parameter; Wherein, the position coordinates on four summits of described correction rectangle is predetermined; Or the position coordinates on four summits of described correction rectangle determines according to the position coordinates on four summits of view field in described photographic images.

Described projecting apparatus further comprises: authentication module, for carrying out geometric distortion judgement to view field in described photographic images, and geometric distortion judged result is sent to described correction module; And described correction module, specifically for after determining that described geometric distortion judged result is distortion, is determined the view field in described photographic images, and is determined corresponding geometric correction parameter; And use described geometric correction parameter to make operation transform to needing the original image of projection, obtain the image after correcting.

Further, cross-color judged result also for carrying out cross-color judgement to view field in described photographic images, and is sent to described correction module by described authentication module.

Described correction module is also for after determining that described cross-color judged result is distortion, according to the relative position between chromaticity coordinates in hue coordinate system of the background colour of the view field in the photographic images of the current acquisition of described photographing module and the chromaticity coordinates of object color component in hue coordinate system, determine primary colours to be adjusted, and the brightness adjustment value of the primary colours to be adjusted determined is sent to described projection module, described brightness adjustment value is predetermined, and described projection module is also for the brightness of the corresponding primary colours of the brightness adjustment value adjustment light source according to described primary colours to be adjusted, and, described correction module is also for continuing the photographic images obtaining described photographing module current shooting, and the relative distance between the chromaticity coordinates of the background colour of view field in the photographic images determining the current acquisition of described photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system is when being less than set point, continue according to the relative position between chromaticity coordinates in hue coordinate system of the background colour of the view field in the photographic images of the current acquisition of described photographing module and the chromaticity coordinates of object color component in hue coordinate system, determine primary colours to be adjusted, and the brightness adjustment value of the primary colours to be adjusted determined is sent to described projection module.

Wherein, described authentication module comprises: geometric distortion judging unit, for carrying out geometric distortion judgement to view field in described photographic images, and geometric distortion judged result is sent to described correction module; Cross-color judging unit, for carrying out cross-color judgement to view field in described photographic images, and sends to described correction module by cross-color judged result.

Described correction module comprises: geometric correction processing unit, for receiving the geometric distortion judged result that described geometric distortion judging unit sends, if described geometric distortion judged result is distortion, then determine the view field in described photographic images, and determine corresponding geometric correction parameter, using described geometric correction parameter to make operation transform to needing the original image of projection, obtaining the image after correcting, color correction process unit, for receiving the cross-color judged result that described cross-color judging unit sends, if described cross-color judged result is distortion, then: according to the relative position between chromaticity coordinates in hue coordinate system of the background colour of the view field in the photographic images of the current acquisition of described photographing module and the chromaticity coordinates of object color component in hue coordinate system, determine primary colours to be adjusted, and the brightness adjustment value of the primary colours to be adjusted determined is sent to described projection module, and, after described projection module is according to the brightness of the corresponding primary colours of the brightness adjustment value adjustment light source of described primary colours to be adjusted, continue the photographic images obtaining described photographing module current shooting, and the relative distance between the chromaticity coordinates of the background colour of view field in the photographic images determining the current acquisition of described photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system is when being less than set point, continue according to the relative position between chromaticity coordinates in hue coordinate system of the background colour of the view field in the photographic images of the current acquisition of described photographing module and the chromaticity coordinates of object color component in hue coordinate system, determine primary colours to be adjusted, and the brightness adjustment value of the primary colours to be adjusted determined is sent to described projection module.

Described projection module comprises: image-driven unit, for projecting according to the image after the correction of described geometric correction processing unit transmission; Light source driving units, the brightness adjustment value for the primary colours to be adjusted sent according to described color correction process unit adjusts the brightness of the corresponding primary colours of light source.

The projecting apparatus of the embodiment of the present invention is owing to analyzing the view field in photographic images, carry out geometric correction process or color correction process, thus the predetermined image of certain feature need not be had by projection, carry out correct operation, thus simplify the process of correcting orthographic projection image.

Because the projecting apparatus of the embodiment of the present invention is in the process of carrying out geometric correction or color correction, need not project and there is the predetermined image of certain feature, therefore, above-mentioned S501-S507 step, or S801-S807 step not only can perform trimming process at the baseline of projection, also can in normal projection process, by photographing module Real-time Obtaining photographic images, authentication module can carry out geometric distortion judgement to photographic images in real time or cross-color judges, correction module can carry out geometric correction process or color correction process in real time.Therefore, the projecting apparatus of the embodiment of the present invention and projected picture correcting method thereof can carry out geometric correction or color correction more conveniently.

Because the projecting apparatus of the embodiment of the present invention can realize color correction, making the application scenario of projecting apparatus be not limited to display screen is white occasion.For the display screen of other color, as ecru etc., can color adjustment be passed through, and make the image effect that projects identical with the effect projected on white displays screen, projecting apparatus be used more convenient.

Accompanying drawing explanation

Fig. 1 is the internal frame diagram with the projecting apparatus of automatic calibration projected image function of prior art;

Fig. 2 is the not calibrated schematic diagram occurring the projected image of geometric distortion of the embodiment of the present invention;

Fig. 3 is schematic diagram original image being obtained after transform operation the image after correcting of the embodiment of the present invention;

Fig. 4,7 is the projecting apparatus block diagram of the embodiment of the present invention;

Fig. 5 is the projected image geometric correction method flow chart of the embodiment of the present invention;

Fig. 6 is the schematic diagram on the determination correction rectangle summit of the embodiment of the present invention;

Fig. 8 is projected image geometric correction and the color calibration method flow chart of the embodiment of the present invention;

Fig. 9 a is the chromaticity coordinates of hue coordinate Xi Zhong view field background colour of the embodiment of the present invention and the schematic diagram of the chromaticity coordinates of object color component;

Fig. 9 b is the detailed color calibration method flow chart of the embodiment of the present invention;

Figure 10 is the schematic diagram that the adjustment T point of the embodiment of the present invention overlaps with W point;

Figure 11 is a kind of projecting apparatus internal structure schematic diagram of the embodiment of the present invention.

Embodiment

For making object of the present invention, technical scheme and advantage clearly understand, enumerate preferred embodiment referring to accompanying drawing, the present invention is described in more detail.But it should be noted that, the many details listed in specification are only used to make reader to have a thorough understanding, even if do not have these specific details also can realize these aspects of the present invention to one or more aspect of the present invention.

The term such as " module " used in this application, " system " is intended to comprise the entity relevant to computer, such as but not limited to hardware, firmware, combination thereof, software or executory software.Such as, module can be, but be not limited in: the thread of the process that processor runs, processor, object, executable program, execution, program and/or computer.For example, application program computing equipment run and this computing equipment can be modules.One or more module can be positioned at an executory process and/or thread, and module also and/or can be distributed on a computer between two or more platform computers.In addition, these modules can be performed by the multiple computer-readable medium storing plurality of data structures.These modules can utilize this locality and/or remote process to communicate by signal.

The present inventor finds, if the optical axis that projector projects goes out becomes an angle of inclination with screen surface, the view field demonstrated so on the display screen can not be the rectangle of rule, but a kind of quadrangle of distortion, namely there is geometric distortion.If projecting apparatus needs by certain width image projection on display screen, such as, need certain page of lantern slide projection in PPT document on display screen; Or, need certain photos to project on display screen; So, because the optical axis projected becomes an angle of inclination with screen surface, also correspondingly can there is geometric distortion in projected image shown in view field on the display screen.Fig. 2 shows a kind of not calibrated and occur the projected image of geometric distortion.

Analyze based on this, thinking of the present invention is: need the original image of projection to correct to projecting apparatus in advance, such as, shown in Fig. 3, by the original image of a width rectangle after certain transform operation, obtains the image after correcting.Image after correction has not been the rectangle of rule, but there occurs the irregular quadrangle after Geometrical change.Image after this corrects by projecting apparatus, namely after this irregular quadrilateral image projects, the deformation factor that the distortion of the image after this correction just in time produces with inclined light shaft offsets, thus the projected image shown in the view field of display screen is the rectangular image of rule.That is, the image after correction is after projection, and the projected image shown in view field does not have geometric distortion relative to original image.And can draw with reference to the distortion degree of view field the parameter that original image carries out transform operation.That is, by camera shooting projecting apparatus view field on the display screen, analyze the distortion situation of view field in photographic images, just can calculate the parameter (or claiming geometric correction parameter) of anti-distortion.Utilize anti-distortion parameter (or claim geometric correction parameter) to convert original image, obtain the image after correcting, just can make projecting apparatus by the image projection after correction to display screen time, no longer include geometric distortion.

The technical scheme of the embodiment of the present invention is described in detail below in conjunction with accompanying drawing.As shown in Figure 4, a kind of projecting apparatus that the embodiment of the present invention provides comprises: photographing module 401, projection module 402, correction module 403.

Projection module 402 projects light onto on display screen, demonstrates the view field that brightness is higher on the display screen, and namely the brightness of view field is higher than the brightness of the non-view field not having projection ray to irradiate.If projection module 402 also projects image onto on display screen, so corresponding projected image will be demonstrated in view field.If the optical axis that projection module 402 projects becomes an angle of inclination with screen surface, the view field of the high brightness so display screen demonstrated can not be the rectangle of rule, but a kind of quadrangle of distortion, namely there is geometric distortion.Suppose, a width does not project in view field through the original image of correction process by projection module 402 again, and so projected image also there will be corresponding geometric distortion.

Photographing module 401 is fixedly installed on projecting apparatus, preferably, is disposed adjacent in projection module 402, such as, is arranged on the top of projection module 402, take, obtain photographic images for the view field projected on the display screen projecting apparatus.In actual applications, photographing module 401 can be taken continuously to the view field that display screen projects.

Correction module 403, for determining that according to the view field in photographic images corresponding geometric correction parameter carries out geometric correction process.Particularly, correction module 403 determines the position coordinates on four summits of view field in photographic images; And the position coordinates on four summits according to the view field determined, after calculating geometric correction parameter, using geometric correction parameter to make operation transform to needing the original image of projection, obtaining the image after correcting.Image after the correction calculated is sent to projection module 402 by correction module 403.

Image after correction projects by projection module 402.After the distortion factor that the distortion factor of the image after correction and inclined light shaft produce offsets, demonstrate the projected image not having geometric distortion relative to original image on the display screen, thus achieve the correction of projected image.

The projecting apparatus introducing the embodiment of the present invention below in detail carries out the method for geometric correction to projected image, as shown in Figure 5, in step S501, projection module 402 projects light onto on display screen flow process, demonstrates the view field that brightness is higher on the display screen.Certainly, time projection module 402 shows view field on the display screen, both can project to image, also can not carry out image projection.If carry out image projection, corresponding projected image will be demonstrated in view field.Next, in step S502, the view field that the projection module 402 of photographing module 401 pairs of projecting apparatus projects on the display screen takes, and obtains photographic images.Then, correction module 403 determines the view field (step S503) in photographic images.Particularly, because the image of shooting is preserved in the mode of pixel-matrix usually, each pixel includes positional information, the monochrome information of this pixel.Positional information i.e. this pixel position coordinates in the picture, and monochrome information can be the brightness value of this pixel.In image captured by photographing module 401, both include the view field that on display screen, brightness is higher, also include subregion display screen not having project.Therefore, in photographic images, the brightness value of view field is greater than the region not having to project.So, the brightness value of the pixel analyzed in photographic images can determine the border of view field.How to determine the technology that the border of view field is well known to those skilled in the art to repeat no more herein according to the brightness value of the pixel in photographic images.In step S504, correction module 403, according to the view field of described photographic images, determines corresponding geometric correction parameter.Particularly, correction module 403 is determining in photographic images after view field, can recognize the degree of the geometric distortion that projecting apparatus optical axis causes because of inclination, and then determine anti-distortion parameter, i.e. geometric correction parameter.Such as, correction module 403 can get the position coordinates of four points in view field, recognizes the degree of the geometric distortion that projecting apparatus optical axis causes because of inclination, and then determine anti-distortion parameter according to the position coordinates of these four points.The transformation theory of above-mentioned elimination distortion can be solved by mathematical computations mode.One preferably scheme is, because view field is generally quadrangle, therefore can recognize the degree of the geometric distortion that projecting apparatus optical axis causes because of inclination according to the position coordinates on four of view field in a photographic images summit, and then determine anti-distortion parameter, i.e. geometric correction parameter.Suppose, be in the xy coordinate system of forward in x-axis and y-axis, in described photographic images, four summits of view field are from the upper left corner, are followed successively by A, B, C, D point clockwise, and the position coordinates on A, B, C, D tetra-summits is respectively (x ₁, y ₁), (x ₂, y ₂), (x ₃, y ₃), (x ₄, y ₄).

In fact, can according to the position coordinates on four of a view field summit, and certain corrects the position coordinates on four summits of rectangle, determines geometric correction parameter.Suppose herein, be in the xy coordinate system of forward in x-axis and y-axis, four summits of this correction rectangle, from the upper left corner, be followed successively by A ', B ', C ', D ' point clockwise, and the position coordinates of A ', B ', C ', D ' are respectively (x ₁', y ₁'), (x ₂', y ₂'), (x ₃', y ₃'), (x ₄', y ₄').

The position coordinates correcting four summits of rectangle can be predetermined.Such as, setting corrects the rectangular area that rectangle is a setting size placed in the middle in photographic images, and thus, the position coordinates correcting four summits of rectangle is also setting.

Or the position coordinates correcting four summits of rectangle can be determine according to the position coordinates on four summits of view field in described photographic images.Preferably, correcting rectangle can be the rectangle being positioned at view field, namely for the quadrangle be made up of four summits of view field in described photographic images, determines that the position coordinates on four summits of described correction rectangle is positioned within described quadrangle.Further, consistent with the ratio of width to height of original image in order to ensure the image after correcting, that is, in order to avoid there is the situation that image is crushed or stretches, within the quadrangle that four summits allowing the position coordinates on four summits of described correction rectangle be arranged in described photographic images view field are formed, the ratio of width to height of this correction rectangle can also be made identical with the ratio of width to height of original image.How to determine that corrects a rectangle, within the quadrangle that four summits making this correction rectangle be arranged in photographic images view field are formed, and the ratio of width to height of this correction rectangle is identical with the ratio of width to height of original image, the technology be well known to those skilled in the art, repeats no more herein.

As shown in Figure 6, following equation 1-4 gives a kind of method determining the position coordinates on four summits of the correction rectangle being positioned at view field:

X ₁'=x ₄'=max (x ₁, x ₄); (equation 1)

X ₂'=x ₃'=min (x ₂, x ₃); (equation 2)

Y ₁'=y ₂'=min (y ₁, y ₂); (equation 3)

Y ₃'=y ₄'=max (y ₃, y ₄); (equation 4)

Above-mentioned max is expressed as and gets maximum to the value in bracket, and min is expressed as and gets minimum value to the value in bracket.

Correction module 403 is according to the position coordinates on four summits of view field in described photographic images, and the position coordinates on four summits of correction rectangle, calculates geometric correction parameter according to following formula 1:

$\left[\begin{array}{c}{x_i}^{\′}\\ {y_i}^{\′}\end{array}\right]=\frac{\left[\begin{array}{cc}a& b\\ c& d\end{array}\right]\left[\begin{array}{c}{x}_i\\ y_i\end{array}\right]+\left[\begin{array}{c}e\\ f\end{array}\right]}{1+\left[\mathrm{u\; v}\right]\left[\begin{array}{c}{x}_i\\ y_i\end{array}\right]}$ (formula 1)

In above-mentioned formula 1, i is the integer between [Isosorbide-5-Nitrae]; A, b, c, d, e, f, u, v are the geometric correction parameter calculated.

Next, in step S505, correction module 403 uses geometric correction parameter to make operation transform to needing the original image of projection, obtains the image after correcting.Suppose, the position coordinates of certain pixel in original image is (x, y), then can calculate the position coordinates (x ', y ') of respective pixel in the image after correction according to following formula 2:

$\left[\begin{array}{c}{x}^{\′}\\ y^{\′}\end{array}\right]=\frac{\left[\begin{array}{cc}a& b\\ c& d\end{array}\right]\left[\begin{array}{c}x\\ y\end{array}\right]+\left[\begin{array}{c}e\\ f\end{array}\right]}{1+\left[\mathrm{u\; v}\right]\left[\begin{array}{c}x\\ y\end{array}\right]}$ (formula 2)

Obviously, the position coordinates of the arbitrary pixel in original image can be updated to the x in above-mentioned formula 2, in y value, thus obtain the position coordinate value x ' of respective pixel in the image after correcting, y '.After all pixels in original image are carried out operation transform according to above-mentioned formula 2, the image after correcting can be obtained.

Further, after original image makes operation transform, the feature of some pixels can be lost, so, in the image that can obtain after operation transform is done to original image, carry out interpolation arithmetic, obtain the image after final correction.By interpolation arithmetic, the pixel lacked because of image scaling can be supplemented, eliminate possible mosaic phenomenon, the content of display frame be seamlessly transitted, does not affect viewing effect.

In step S506, the image after correction is sent to projection module 402 by correction module 403.In step S507, projection module 402 by correct after image projection on display screen.By the image after the correction that obtains after operation transform, certain geometric distortion is created relative to original image, after the distortion factor that the distortion factor of the image after correction and inclined light shaft produce offsets, demonstrate the projected image not having geometric distortion relative to original image on the display screen, thus achieve the geometric correction of projected image.

More preferably, authentication module 404 can also be comprised in the projecting apparatus of the embodiment of the present invention, as shown in Figure 7.

Authentication module 404 is arranged between photographing module 401 and correction module 403, for the photographic images obtained photographing module 401, carries out geometric distortion judgement, and geometric distortion judged result is sent to correction module 403.

Preferably, the geometric distortion judged result that correction module 403 sends according to authentication module 404 determines whether carry out geometric correction process:

If geometric distortion judged result is distortion, then correction module 403 is according to the method for above-mentioned steps S503-S505, makes operation transform to original image, obtains the image after correcting, and sends to projection module 402 to carry out Projection Display the image after correcting.If geometric distortion judged result is undistorted, then correction module 403 need not carry out geometric correction process, is directly sent to by original image projection module 402 to carry out Projection Display.

In projection process, except occurring except geometric distortion, also can there is deviation in the color of image, and occur cross-color.Such as, projected image entirety is partially orange, is a kind of cross-color.

Further, the projecting apparatus of the embodiment of the present invention can also carry out color correction process.Particularly, authentication module 404 can also carry out the photographic images obtained photographing module 401, carries out cross-color judgement, and cross-color judged result is sent to correction module 403.

The cross-color judged result that correction module 403 Receipt Validation module 404 sends, and determine whether carry out color correction process according to cross-color judged result:

If cross-color judged result is distortion, then correction module 403 is according to the background colour of the view field in the photographic images of the current acquisition of photographing module, determines primary colours to be adjusted, and the brightness adjustment value of primary colours to be adjusted is sent to projection module 402; Projection module 402 is according to the brightness adjustment value of the primary colours to be adjusted received afterwards, the brightness of the corresponding primary colours of adjustment light source; The view field that photographing module 401 continues the projection module 402 of projecting apparatus projects on the display screen takes, and obtains photographic images.Correction module 403 continues the photographic images obtaining photographing module 401 current shooting, and the relative distance between the chromaticity coordinates of the background colour of view field in the photographic images determining the current acquisition of photographing module 401 in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system is when being less than set point, terminate this color correction; Otherwise, continue according to the relative position between chromaticity coordinates in hue coordinate system of the background colour of the view field in the photographic images of the current acquisition of described photographing module and the chromaticity coordinates of object color component in hue coordinate system, determine primary colours to be adjusted, and the brightness adjustment value of these primary colours to be adjusted is continued to send to projection module 402.Concrete color correction process method will be introduced follow-up.If cross-color judged result is undistorted, then correction module 403 need not carry out color correction process, does not namely send the brightness adjustment value of primary colours to be adjusted to projection module 402.The luminance primary of projection module 402 pairs of projection light sources does not change.

The geometric distortion of the projecting apparatus of the embodiment of the present invention judges, trimming process, and cross-color judges, the flow process of trimming process, as shown in Figure 8.In step S801, projection module 402 projects light onto on display screen, demonstrates the view field that brightness is higher on the display screen.Next, in step S802, the view field that the projection module 402 of photographing module 401 pairs of projecting apparatus projects on the display screen takes, and obtains photographic images.In step S803, the photographic images that authentication module 404 pairs of photographing modules 401 obtain, carries out geometric distortion judgement, and geometric distortion judged result is sent to correction module 403.

Authentication module 404 can according to the length of side ratio of the relative edge of the view field in photographic images, and the angle of adjacent edge carries out geometric distortion judgement.Particularly, in quadrangle view field formed:

If the included angle X of adjacent edge exceeds the scope of setting, then judge to there occurs geometric distortion, the scope such as set is 85 ° ~ 95 °, if λ exceeds this scope, judges to there occurs geometric distortion.Obviously, other methods many are had to judge whether λ exceeds the scope of setting.In an embodiment of the present invention, judge as follows: as setting σ value, if λ meets as lower inequality 1:

$\mathrm{\&sigma;}<\frac{\mathrm{\&lambda;}}{90}<\frac{1}{\mathrm{\&sigma;}}$ (inequality 1)

Then judge that λ does not exceed the scope of setting; Otherwise, judge that λ exceeds the scope of setting.The value of σ can be determined according to actual conditions, as required effective desirable 0.95, requires that effect is not high by desirable 0.8.

If the included angle X of adjacent edge does not exceed the angular range of setting, then proceed the length of side ratio of the relative edge judging view field whether in setting range.The quadrangle of view field, has two pairs of opposite side.Respectively to not judging length of side ratio whether in setting range to opposite side.If there is the length of side ratio of a pair opposite side to exceed setting range, then judge geometric distortion occurs.Such as, be the view field of A, B, C, D point for above-mentioned summit, AB limit and DC limit are opposite side, and AD limit and BC limit are opposite side, l _aB, l _dC, l _aD, l _bCbe respectively the length of side on AB limit, DC limit, AD limit, BC limit.If l _aB, l _dC, l _aD, l _bCone of not meet in following inequality 2 and inequality 3, then judge geometric distortion occurs:

$\mathrm{\&epsiv;}<\frac{l_{\mathrm{AB}}}{l_{\mathrm{DC}}}<\frac{1}{\mathrm{\&epsiv;}}$ (inequality 2)

$\mathrm{\&epsiv;}<\frac{l_{\mathrm{AD}}}{l_{\mathrm{BC}}}<\frac{1}{\mathrm{\&epsiv;}}$ (inequality 3)

Those skilled in the art can set ε value according to actual conditions.Such as, as required, the effective ε of setting is 0.95 preferably, if require that the not high ε of setting of effect is 0.8; In general, the setting range of ε can be (0.6≤ε≤1).

In step S804, authentication module 404 can also carry out the current photographic images taken photographing module 401, carries out cross-color judgement, and cross-color judged result is sent to correction module 403.

Particularly, authentication module 404 can according to photographic images, determine the chromaticity coordinates of the background colour of the view field in photographic images in hue coordinate system, carry out cross-color judgement according to the distance between the chromaticity coordinates of background colour and the chromaticity coordinates of object color component in hue coordinate system.Suppose that the chromaticity coordinates of view field's background colour is the T point in hue coordinate system, the chromaticity coordinates of object color component is the W point (as illustrated in fig. 9) in hue coordinate system.The chromaticity coordinates of object color component is what preset.Authentication module 404 calculates the distance between T point to W point, if distance exceedes setpoint distance value, then determines that cross-color judged result is distortion; Otherwise, determine that described cross-color judged result is undistorted.Such as, calculate T point and the distance δ of W point in hue coordinate system, as met 0≤δ≤γ, then can think and meet the requirements, γ span is redefined for 0≤γ≤0.03.

Determine that a kind of concrete grammar of the chromaticity coordinates of the background colour of the view field in photographic images can be: after determining four summits of the view field in photographic images, obtain the chromaticity coordinates on these four summits.Using the chromaticity coordinates of the mean value of the chromaticity coordinates on these four summits as the background colour of the view field in photographic images.Such as, suppose that the chromaticity coordinates on four summits of the view field in photographic images is respectively: (x _c1, y _c1), (x _c2, y _c2), (x _c3, y _c3), (x _c4, y _c4).Chromaticity coordinates (the x of the background colour of the view field then in photographic images _c, y _c), determine according to following equation 5,6:

$x_c=\frac{x_{c1}+x_{c2}+x_{c3}+x_{c4}}{4}$ (equation 5)

$y_c=\frac{y_{c1}+y_{c2}+y_{c3}+y_{c4}}{4}$

(equation 6)

Not only can determine the chromaticity coordinates of the background colour of view field for those skilled in the art with the chromaticity coordinates on four summits of view field, the chromaticity coordinates of other point in view field also can be adopted to determine.

Obviously, step S803 and S804 can perform simultaneously, also first can perform S803, or first perform S804.

In step S805, if geometric distortion judged result is distortion, then correction module 403 pairs of original images carry out geometric correction process, obtain the image after correcting, and send to projection module 402 to carry out Projection Display the image after correcting.Namely correction module 403 determines corresponding geometric correction parameter according to the view field in described photographic images, geometric correction parameter is used to carry out geometric correction process to original image, after obtaining the image after correcting, projection module 402 is sent to carry out Projection Display the image after correcting.The method of correction module 403 geometric correction process is described in detail in detail in above-mentioned steps S503-S505, has repeated no more herein.

Next in step S806, if geometric distortion judged result is undistorted, then correction module 403 need not carry out geometric correction process, is directly sent to by original image projection module 402 to carry out Projection Display.If cross-color judged result is distortion, then color correction process (step S807) is carried out in the cooperation of correction module 403, photographing module 401 and projection module 402.

The cooperation of correction module 403, photographing module 401 and projection module 402 carries out the detailed process of color correction process as shown in figure 9b.In step S901, the view field that photographing module 401 pairs of projecting apparatus project on the display screen takes, and obtains photographic images.Correction module 403, according to the background colour of the view field in the photographic images of the current acquisition of photographing module, determines primary colours to be adjusted (step S902).Particularly, correction module 403, according to the relative position between the chromaticity coordinates of the background colour of the view field in the photographic images of the current acquisition of photographing module 401 in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system, determines primary colours to be adjusted.

Particularly, correction module 403 is according to photographic images, determine the chromaticity coordinates of the background colour of the view field in photographic images in hue coordinate system, according to chromaticity coordinates and the chromaticity coordinates of object color component in hue coordinate system of background colour, determine primary colours to be adjusted, after making to have adjusted these primary colours to be adjusted, the background colour of the view field in the photographic images again taken is close to object color component; Namely, after making to have adjusted these primary colours to be adjusted, the chromaticity coordinates of the background colour of the view field in the photographic images again taken is close to the chromaticity coordinates of object color component.

Concrete grammar can be as shown in Figure 10, the chromaticity coordinates of three primary light source is respectively R, G, B point in hue coordinate system, the chromaticity coordinates of object color component is W point in hue coordinate system, and the chromaticity coordinates of the view field's background colour in the photographic images of current shooting is T point in hue coordinate system.R, W point is connected and extended and obtains straight line RW, G, W point connects and extends and obtains straight line GW, and B, W point connects and extends and obtains straight line BW.

First among straight line RW, GW, BW, determine the straight line nearest with T point, the straight line nearest according to this determines the brightness adjustment value of primary colours to be adjusted and these primary colours to be adjusted.Specifically comprise as follows: the brightness judging which primary colours adjusting T point, T point can be made to this nearest rectilinear movement, then these primary colours are primary colours to be adjusted.Such as, determine T point and straight line BW nearest, in Fig. 10 because T point and G point are positioned at the same side of straight line BW, then T point can be made by the R luminance primary heightening T point to move to straight line BW, thus, judge that these primary colours to be adjusted are R primary colours; Certainly, also by reducing the brightness of other dichromatism of T point, namely reducing B and G luminance primary and T point is moved to straight line BW, thus, judging that these primary colours to be adjusted are B and G primary colours.

For the situation that the distance between T point and straight line is less than setting threshold or coincides, then judge that the method for these primary colours to be adjusted is: the brightness judging which primary colours adjusting T point, T point can be made mobile to W point, then these primary colours are primary colours to be adjusted.Such as, T point overlaps with straight line BW, T point can be made to move to W by the B luminance primary heightening T point, thus, judges that these primary colours to be adjusted are B primary colours; Certainly, also by reducing the brightness of other dichromatism of T point, namely reducing R and G luminance primary and T point is moved to W, judging that primary colours to be adjusted are R and G primary colours thus.Those skilled in the art can arrange setting threshold according to actual conditions.

Another kind of judge that the preferred approach of primary colours to be adjusted is: as shown in Figure 10, straight line RW comprises the extended line of line segment between RW and RW line segment; Straight line BW comprises the extended line of line segment between BW and BW line segment; Straight line GW comprises the extended line of line segment between GW and GW line segment.First, the extended line nearest with T point is determined.Judge that the method for primary colours to be adjusted is: the brightness judging which primary colours adjusting T point, T point can be made to move to this nearest extended line, then these primary colours are primary colours to be adjusted.Determination methods and above-mentioned similar, repeats no more herein.

For the situation that the distance between T point and this nearest extended line is less than setting threshold or coincides, then judge that the method for these primary colours to be adjusted is: the brightness judging which primary colours adjusting T point, T point can be made mobile to W point, then these primary colours are primary colours to be adjusted.Such as, T point overlaps with the extended line of BW line segment, T point can be made to move to W by the B luminance primary heightening T point, thus, judges that these primary colours to be adjusted are B primary colours.

By this method, light source can be adjusted by increasing luminance primary, instead of minimizing luminance primary adjusts light source.

In step S903, the brightness adjustment value of the primary colours to be adjusted determined is sent to projection module 402 by correction module 403.The brightness adjustment value of these primary colours to be adjusted, after determining primary colours to be adjusted, can be sent to projection module 402 by correction module 403.Such as, in above-mentioned example, T point can be made to move to straight line BW by the R luminance primary heightening T point, judge these primary colours to be adjusted to be R primary colours thus, owing to being heighten R luminance primary, therefore, brightness adjustment value can be one predetermined on the occasion of.This brightness adjustment value is a predetermined proper step value, determines again and again primary colours to be adjusted, and send brightness adjustment value to projection module 402 by follow-up, makes T point final close with W point or overlap.

For another example, in above-mentioned example, by reducing the brightness of other dichromatism of T point, namely reducing B and G luminance primary makes T point move to straight line BW, thus, judge that these primary colours to be adjusted are B and G primary colours, owing to being reduction B and G luminance primary, therefore, the brightness adjustment value of B and G can be a predetermined negative value.

In step S904, projection module 402, according to the brightness adjustment value of the primary colours to be adjusted received, adjusts the brightness of the corresponding primary colours of light source.Particularly, projection module 402 is after receiving the brightness adjustment value of primary colours to be adjusted, and such as, brightness adjustment value is the brightness adjustment value of R primary colours, and this brightness adjustment value is just, then certain brightness of the R primary colours of projection module 402 corresponding raising light source.For another example, brightness adjustment value is the brightness adjustment value of B and G primary colours, and this brightness adjustment value is negative, then certain brightness of B and the G primary colours of projection module 402 corresponding reduction light source.The degree that projection module 402 improves or reduce luminance primary is determined according to the absolute value of brightness adjustment value.Have adjusted the luminance primary of light source at projection module 402 after, the background colour projecting to the image on display screen will change.

In step S905, correction module 403 continues the photographic images obtaining photographing module 401 current shooting, and judges whether the relative distance between the chromaticity coordinates of the background colour of the view field in the photographic images of current acquisition and the chromaticity coordinates of object color component is less than set point; If be less than, then terminate this color correction, perform step S906; Otherwise, repeat step S902-S905.

Have adjusted the luminance primary of light source at projection module 402 after, also can there is respective change in the background colour of the view field in the photographic images that photographing module 401 obtains.Correction module 403 continues to compare the chromaticity coordinates of the background colour of the view field that there occurs change and the chromaticity coordinates of object color component.If both relatively or overlap, so just reach the object of color correction, just can terminate this color correction process; Otherwise, also need to proceed color correction.Those skilled in the art can determine set point according to actual conditions, if require higher, set point can arrange less; To ask lower, set point can arrange larger.Certainly, also set point can be set to 0, namely represent situation about overlapping completely.This set point can arrange identical with above-mentioned setpoint distance value, or less than above-mentioned setpoint distance value.

By repeating step S902-S905, making the chromaticity coordinates W point of the chromaticity coordinates T point of the background colour of view field and object color component more and more close, until reach requirement, thus reaching the object of color correction.

Usually, the chromaticity coordinates W point of object color component is positioned at the triangle that R, G, B point is formed.Straight line RW, GW, BW cross straight line BG, BR, GR respectively in some P, N, M, and triangle RGB is divided into multiple little triangle.

List under T point lays respectively at different little leg-of-mutton situation in form as shown in table 1, determine the method for primary colours to be adjusted.Such as, T point is positioned to the situation of little triangle RWM, then determines first to increase G luminance primary, namely determine that primary colours to be adjusted are G primary colours, and the brightness adjustment value of G primary colours be on the occasion of; Through the brightness adjustment value of the primary colours G primary colours to be adjusted that projection module repeatedly sends according to correction module, gradually the G primary colours of projection light source are adjusted brighter and brighter, make the background colour coordinate of the view field in the photographic images of taking module current shooting more and more near BW straight line (or extended line of BW line segment).The background colour coordinate of the view field in the photographic images of taking module current shooting, namely T point overlaps with BW straight line (or extended line of BW line segment) or is less than setting threshold, then determine to increase B luminance primary, namely determine that primary colours to be adjusted are B primary colours, and the brightness adjustment value of B primary colours be on the occasion of.

Table 1

Residing triangle	The first step increases luminance primary	Second step increases luminance primary
			GWM	R	B
GWP	B	R
			RWM	G	B
RWN	B	G
			BWP	G	R
BWN	R	G

The mode of the primary colours to be adjusted of the determination shown in above-mentioned table 1 specifically describes as follows:

If T point is positioned at little triangle GWM or BWN, then determine that primary colours to be adjusted are R primary colours, and the brightness adjustment value of R primary colours be on the occasion of;

If T point is positioned at little triangle GWP or RWN, then determine that primary colours to be adjusted are B primary colours, and the brightness adjustment value of B primary colours be on the occasion of;

If T point is positioned at little triangle RWM or BWP, then determine that primary colours to be adjusted are G primary colours, and the brightness adjustment value of G primary colours be on the occasion of;

If T point overlaps with the extended line of BW line segment or is less than setting threshold, then determine that primary colours to be adjusted are B primary colours, and the brightness adjustment value of B primary colours be on the occasion of;

If T point overlaps with the extended line of RW line segment or is less than setting threshold, then determine that primary colours to be adjusted are R primary colours, and the brightness adjustment value of R primary colours be on the occasion of;

If T point overlaps with the extended line of GW line segment or is less than setting threshold, then determine that primary colours to be adjusted are G primary colours, and the brightness adjustment value of G primary colours be on the occasion of.

In step S906, terminate this color correction.Correction module 403 no longer sends the brightness adjustment value of primary colours to projection module 402, projection module 402 will maintain the current luminance primary of projection light source.

The concrete internal structure schematic diagram of one of embodiment of the present invention projecting apparatus, as shown in figure 11, comprising: photographing module 401, projection module 402, correction module 403, authentication module 404.

Wherein, the structure function of photographing module 401, with described identical before, repeats no more herein.

Geometric distortion judging unit 1101 and cross-color judging unit 1102 specifically can be comprised in authentication module 404.

The photographic images of geometric distortion judging unit 1101 for obtaining photographing module 401, carries out geometric distortion judgement, and geometric distortion judged result is sent to correction module 403.Geometric distortion judging unit 1101 carries out the method for geometric distortion judgement previously in identical described in step S803, repeats no more herein.The photographic images of cross-color judging unit 1102 for obtaining photographing module 401, carries out cross-color judgement, and cross-color judged result is sent to correction module 403.Cross-color judging unit 1102 carries out the method for cross-color judgement previously in identical described in step S804, repeats no more herein.

Geometric correction processing unit 1103 and color correction process unit 1104 can be comprised in correction module 403.The geometric distortion judged result that geometric correction processing unit 1103 sends for receiving geometric distortion judging unit 1101, and according to geometric distortion judged result, carry out geometric correction process.Particularly, if geometric distortion judged result is distortion, geometric correction processing unit 1103 pairs of original images carry out geometric correction process, obtain the image after correcting, and send to projection module 402 to carry out Projection Display the image after correcting; If geometric distortion judged result is undistorted, then geometric correction processing unit 1103 need not carry out geometric correction process, is directly sent to by original image projection module 402 to carry out Projection Display.Geometric correction processing unit 1103 pairs of original images carry out geometric correction process, and the method obtaining the image after correcting is identical with the method described in detail in step S503-S505 before, repeats no more herein.

The cross-color judged result that color correction process unit 1104 sends for receiving cross-color judging unit 1102; And according to cross-color judged result, carry out color correction process.Particularly, if described cross-color judged result is distortion, then: according to the chromaticity coordinates of background colour in hue coordinate system of the view field in the photographic images of the current acquisition of photographing module 401, and the relative position between the chromaticity coordinates of object color component in hue coordinate system, determine primary colours to be adjusted, and the brightness adjustment value of the primary colours to be adjusted determined is sent to projection module 402, and, after projection module 402 is according to the brightness of the corresponding primary colours of the brightness adjustment value adjustment light source of described primary colours to be adjusted, continue the photographic images obtaining photographing module 401 current shooting, and the relative distance between the chromaticity coordinates of the background colour of view field in the photographic images determining the current acquisition of described photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system is when being less than set point, continue the chromaticity coordinates of background colour in hue coordinate system according to the view field in the photographic images of the current acquisition of photographing module 401, and the relative position between the chromaticity coordinates of object color component in hue coordinate system, determine primary colours to be adjusted, and the brightness adjustment value of the primary colours to be adjusted determined is sent to projection module 402.If cross-color judged result is undistorted, then color correction process unit 1104 need not carry out any process, and projection module 402 will maintain the current luminance primary of light source.Color correction process unit 1104 in correction module 403 and photographing module 401, and light source driving units 1106 in projection module 402 coordinates the method for carrying out color correction process to coordinate the method flow carrying out color correction process identical with correction module 403 as shown in figure 9b, photographing module 401 before with projection module 402, repeats no more herein.

Projection module 402 comprises image-driven unit 1105 and light source driving units 1106.Image-driven unit 1105 projects for the image sent according to geometric correction processing unit 1103.The image that geometric correction processing unit 1103 sends can be the image after correcting, or original image.Light source driving units 1106 is for the brightness of the corresponding primary colours of the brightness adjustment value adjustment light source of the primary colours to be adjusted that send according to color correction process unit 1104.

Because above-mentioned cross-color judges and color correction process, and do not rely on geometric distortion judgement and geometric correction process, that is, when not carrying out geometric distortion judgement and correction, projecting apparatus only can carry out cross-color judgement and correction.Therefore, in actual applications, the authentication module of above-mentioned projecting apparatus also can be the function only with cross-color judgement, namely only has cross-color judging unit 1102.Correction module also can be the function only with color correction process, namely only has color correction process unit 1104.And in the process step of trimming process as shown in Figure 8, also can realize separately cross-color by means of only step S801-S802, S804, S807 and judge and color correction process.

The projecting apparatus of the embodiment of the present invention is owing to passing through the analysis to the view field in photographic images, carry out geometric correction process or color correction process, thus the predetermined image of certain feature need not be had by projection, realize carrying out correct operation, thus simplify the process of correcting orthographic projection image.

Because the projecting apparatus of the embodiment of the present invention is in the process of carrying out geometric correction or color correction, need not project and there is the predetermined image of certain feature, therefore, above-mentioned S501-S507 step, or S801-S807 step not only can perform trimming process at the baseline of projection, also can in normal projection process, by photographing module Real-time Obtaining photographic images, authentication module can carry out geometric distortion judgement to photographic images in real time or cross-color judges, correction module can carry out geometric correction process or color correction process in real time.Therefore, the projecting apparatus of the embodiment of the present invention and projected picture correcting method thereof can carry out geometric correction or color correction more conveniently.

Because the projecting apparatus of the embodiment of the present invention can realize color correction, making the application scenario of projecting apparatus be not limited to display screen is white occasion.For the display screen of other color, as ecru etc., can color adjustment be passed through, and make the image effect that projects identical with the effect projected on white displays screen, projecting apparatus be used more convenient.

One of ordinary skill in the art will appreciate that all or part of step realized in above-described embodiment method is that the hardware that can carry out instruction relevant by program has come, this program can be stored in a computer read/write memory medium, as: ROM/RAM, magnetic disc, CD etc.

The above is only the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (14)

1. a projected picture correcting method, comprising:

By photographing module, the view field that projecting apparatus projects on the display screen is taken, obtain photographic images;

Color correction and geometric correction are carried out to described photographic images;

Described color correction comprises:

A, correction module, according to the relative position between the chromaticity coordinates of the background colour of the view field in the photographic images of the current acquisition of described photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system, determine primary colours to be adjusted; And the brightness adjustment value of the primary colours to be adjusted determined is sent to projection module; Described brightness adjustment value is predetermined;

B, described projection module are according to the brightness of the corresponding primary colours of the brightness adjustment value adjustment light source of described primary colours to be adjusted;

C, described correction module continue the photographic images obtaining described photographing module current shooting, and the relative distance between the chromaticity coordinates of the background colour of view field in the photographic images determining the current acquisition of described photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system is when being less than set point, terminate color correction; Otherwise, repeat step a, b, c;

Described geometric correction comprises:

After correction module receives described photographic images, according to the position coordinates on four summits of the view field in described photographic images, and the position coordinates on four summits of correction rectangle, determine geometric correction parameter; And

Use described geometric correction parameter to obtain the image after correcting to needing the original image of projection as operation transform, the image after the correction calculated is sent to projection module;

By projection module by the image projection after described correction on display screen.

2. the method for claim 1, the position coordinates on described four summits according to described view field, and the position coordinates on four summits of correction rectangle, determine that geometric correction parameter comprises and utilize following formula to carry out computational geometry correction parameter:

$\left[\begin{array}{c}{x_i}^{\&prime;}\\ {y_i}^{\&prime;}\end{array}\right]=\frac{\left[\begin{array}{cc}a& b\\ c& d\end{array}\right]\left[\begin{array}{c}{x}_i\\ y_i\end{array}\right]+\left[\begin{array}{c}e\\ f\end{array}\right]}{1+\left[\begin{array}{cc}u& v\end{array}\right]\left[\begin{array}{c}{x}_i\\ y_i\end{array}\right]}$ (formula 1)

Wherein, i is the integer between [Isosorbide-5-Nitrae], (x ₁, y ₁), (x ₂, y ₂), (x ₃, y ₃), (x ₄, y ₄) be the position coordinates on four summits of described view field; (x ₁', y ₁'), (x ₂', y ₂'), (x ₃', y ₃'), (x ₄', y ₄') be the position coordinates on four summits of described correction rectangle; A, b, c, d, e, f, u, v are the geometric correction parameter calculated.

3. method as claimed in claim 2, described use described geometric correction parameter comprises to needing the original image of projection to obtain the image after correcting as operation transform the position coordinates determining this pixel after the correction corresponding with the position coordinates of the pixel in original image according to following formula:

$\left[\begin{array}{c}{x}^{\&prime;}\\ y^{\&prime;}\end{array}\right]=\frac{\left[\begin{array}{cc}a& b\\ c& d\end{array}\right]\left[\begin{array}{c}x\\ y\end{array}\right]+\left[\begin{array}{c}e\\ f\end{array}\right]}{1+\left[\begin{array}{cc}u& v\end{array}\right]\left[\begin{array}{c}x\\ y\end{array}\right]}$ (formula 2)

In formula, (x, y) is the position coordinates of the pixel in original image, and (x', y') is the position coordinates of this pixel after correcting.

4. the method as described in as arbitrary in claim 1-3, the position coordinates on four summits of described correction rectangle is predefined; Or,

The position coordinates on four summits of described correction rectangle determines according to the position coordinates on four summits of view field in described photographic images.

5. method as claimed in claim 4, the position coordinates on four summits of described correction rectangle is comprising of determining according to the position coordinates on four summits of view field in described photographic images:

For the quadrangle be made up of four summits of view field in described photographic images, determine that the position coordinates on four summits of described correction rectangle is positioned within described quadrangle;

Or, for the described quadrangle be made up of four summits of view field in described photographic images, determine that the position coordinates on four summits of described correction rectangle is positioned within described quadrangle, and the ratio of width to height of described correction rectangle is identical with the ratio of width to height of described original image.

6. method as claimed in claim 5, after correction module receives described photographic images, according to the position coordinates on four summits of the view field in described photographic images, and the position coordinates on four summits of correction rectangle, before determining geometric correction parameter step, described geometric correction also comprises:

Authentication module carries out geometric distortion judgement to view field in described photographic images, and geometric distortion judged result is sent to described correction module.

7. the method for claim 1, by photographing module, the view field that projecting apparatus projects on the display screen is being taken, after obtaining the step of photographic images, also comprising:

Authentication module carries out cross-color judgement to view field in described photographic images, and cross-color judged result is sent to described correction module; And,

Correction module is according to the relative position between the chromaticity coordinates of the background colour of the view field in the photographic images of the current acquisition of described photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system, determine that primary colours to be adjusted are specially: described correction module is after determining that described cross-color judged result is distortion, according to the relative position between chromaticity coordinates in hue coordinate system of the background colour of the view field in the photographic images of the current acquisition of described photographing module and the chromaticity coordinates of object color component in hue coordinate system, determine primary colours to be adjusted.

8. method as claimed in claim 7, described authentication module carries out cross-color to view field in described photographic images and judges to comprise:

If described authentication module determines that the distance between the chromaticity coordinates of the background colour of the view field in the photographic images of the current acquisition of described photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system exceedes setpoint distance value, then determine that described cross-color judged result is distortion; Otherwise, determine that described cross-color judged result is undistorted.

9. method as claimed in claim 8, described correction module, according to the relative position between the chromaticity coordinates of the background colour of the view field in the photographic images of the current acquisition of described photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system, determines that primary colours to be adjusted comprise:

The chromaticity coordinates of three primary light source is respectively R, G, B point in described hue coordinate system, the chromaticity coordinates of described object color component is W point in hue coordinate system, and the chromaticity coordinates of the background colour of the view field in the photographic images of the current acquisition of described photographing module is T point in hue coordinate system; Straight line RW, GW, BW cross straight line BG, BR, GR respectively in some P, N, M, triangle RGB are divided into the little triangle of GWM, BWN, GWP, RWN, RWM, BWP;

If T point is positioned at little triangle GWM or BWN, then determine that primary colours to be adjusted are R primary colours, and the brightness adjustment value of R primary colours be on the occasion of;

If T point is positioned at little triangle GWP or RWN, then determine that primary colours to be adjusted are B primary colours, and the brightness adjustment value of B primary colours be on the occasion of;

If T point is positioned at little triangle RWM or BWP, then determine that primary colours to be adjusted are G primary colours, and the brightness adjustment value of G primary colours be on the occasion of;

If T point overlaps with the extended line of BW line segment or is less than setting threshold, then determine that primary colours to be adjusted are B primary colours, and the brightness adjustment value of B primary colours be on the occasion of;

If T point overlaps with the extended line of RW line segment or is less than setting threshold, then determine that primary colours to be adjusted are R primary colours, and the brightness adjustment value of R primary colours be on the occasion of;

If T point overlaps with the extended line of GW line segment or is less than setting threshold, then determine that primary colours to be adjusted are G primary colours, and the brightness adjustment value of G primary colours be on the occasion of.

10. a projecting apparatus, comprises, photographing module, correction module, authentication module and projection module, wherein:

Described photographing module is used for taking the view field that projecting apparatus projects on the display screen, obtains photographic images;

Described correction module is used for after determining that geometric distortion judged result is distortion, according to the position coordinates on four summits of the view field in described photographic images, and the position coordinates on four summits of correction rectangle, determine geometric correction parameter; And use described geometric correction parameter to make operation transform to needing the original image of projection, obtain the image after correcting, the image after the correction calculated is sent to projection module;

Described authentication module is used for carrying out geometric distortion judgement to view field in described photographic images, and geometric distortion judged result is sent to described correction module; For carrying out cross-color judgement to view field in described photographic images, and cross-color judged result is sent to described correction module;

Described correction module is also for after determining that described cross-color judged result is distortion, according to the relative position between chromaticity coordinates in hue coordinate system of the background colour of the view field in the photographic images of the current acquisition of described photographing module and the chromaticity coordinates of object color component in hue coordinate system, determine primary colours to be adjusted; And the brightness adjustment value of the primary colours to be adjusted determined is sent to described projection module; Described brightness adjustment value is predefined;

Described correction module is also for continuing the photographic images obtaining described photographing module current shooting, and the relative distance between the chromaticity coordinates of the background colour of view field in the photographic images determining the current acquisition of described photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system is when being less than set point, continue, according to the relative position between chromaticity coordinates in hue coordinate system of the background colour of the view field in the photographic images of the current acquisition of described photographing module and the chromaticity coordinates of object color component in hue coordinate system, to determine primary colours to be adjusted; And the brightness adjustment value of the primary colours to be adjusted determined is sent to described projection module; And,

Described projection module, for the brightness of the corresponding primary colours of the brightness adjustment value adjustment light source according to described primary colours to be adjusted; By the image projection after described correction on display screen.

11. projecting apparatus as claimed in claim 10, is characterized in that, the position coordinates on four summits of described correction rectangle is predefined; Or the position coordinates on four summits of described correction rectangle determines according to the position coordinates on four summits of view field in described photographic images.

12. projecting apparatus as claimed in claim 10, it is characterized in that, described authentication module comprises:

Geometric distortion judging unit, for carrying out geometric distortion judgement to view field in described photographic images, and sends to described correction module by geometric distortion judged result;

Cross-color judging unit, for carrying out cross-color judgement to view field in described photographic images, and sends to described correction module by cross-color judged result.

13. projecting apparatus as claimed in claim 12, it is characterized in that, described correction module comprises:

Geometric correction processing unit, for receiving the geometric distortion judged result that described geometric distortion judging unit sends; If described geometric distortion judged result is distortion, then determine the view field in described photographic images, and determine corresponding geometric correction parameter; Using described geometric correction parameter to make operation transform to needing the original image of projection, obtaining the image after correcting;

Color correction process unit, for receiving the cross-color judged result that described cross-color judging unit sends, if described cross-color judged result is distortion, then: according to the relative position between chromaticity coordinates in hue coordinate system of the background colour of the view field in the photographic images of the current acquisition of described photographing module and the chromaticity coordinates of object color component in hue coordinate system, determine primary colours to be adjusted, and the brightness adjustment value of the primary colours to be adjusted determined is sent to described projection module, and, after described projection module is according to the brightness of the corresponding primary colours of the brightness adjustment value adjustment light source of described primary colours to be adjusted, continue the photographic images obtaining described photographing module current shooting, and the relative distance between the chromaticity coordinates of the background colour of view field in the photographic images determining the current acquisition of described photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system is when being less than set point, continue according to the relative position between chromaticity coordinates in hue coordinate system of the background colour of the view field in the photographic images of the current acquisition of described photographing module and the chromaticity coordinates of object color component in hue coordinate system, determine primary colours to be adjusted, and the brightness adjustment value of the primary colours to be adjusted determined is sent to described projection module.

14. projecting apparatus as claimed in claim 13, it is characterized in that, described projection module comprises:

Image-driven unit, for projecting according to the image after the correction of described geometric correction processing unit transmission;

Light source driving units, the brightness adjustment value for the primary colours to be adjusted sent according to described color correction process unit adjusts the brightness of the corresponding primary colours of light source.