CN117596370A - Color correction method for projection picture, projection device and storage medium - Google Patents

Abstract

The invention discloses a color correction method of a projection picture, projection equipment and a storage medium, wherein the color correction method of the projection picture comprises the following steps: projecting a calibration picture to a target projection surface to obtain a first shooting image containing the calibration picture; determining color components of primary colors of each light source in the calibration picture from the first shooting image; determining a current correction value of each light source primary color according to the difference relation between the color components and the corresponding calibration current parameters of the light source primary colors; the calibration current parameter is used for controlling the color and the brightness of the calibration picture; and adjusting the brightness of each light source primary color according to the current correction value of each light source primary color. The invention can correct the projection effect according to the projection environment, thereby improving the display effect of the projection picture in the actual use environment.

Description

Color correction method for projection picture, projection device and storage medium

Technical Field

The present invention relates to the field of projection devices, and in particular, to a color correction method for a projection screen, a projection device, and a storage medium.

Background

The target projection surface of the projection device is usually a wall surface or a curtain, but in many occasions, the wall surface or the curtain is not pure white, such as light blue, beige, light pink wall surface, and some curtains are light gray, and the pure white curtain is light yellow after aging. However, the existing projection device is usually designed to have the best effect on the standard pure white curtain, so when the user encounters the above environmental problem during use, there is a problem that the color effect of the projection screen is deviated.

Disclosure of Invention

Based on the technical problems, the invention provides a color correction method, projection equipment and storage medium for a projection picture, which can correct the projection effect according to the projection environment, thereby improving the display effect of the projection picture in the actual use environment.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

in a first aspect, the present invention discloses a color correction method for a projection screen, including the following steps:

projecting a calibration picture to a target projection surface, and obtaining a first shooting image containing the calibration picture;

determining color components of primary colors of each light source in the calibration picture from the first shooting image;

determining a current correction value of each light source primary color according to the difference relation between the color components and the corresponding calibration current parameters of the light source primary colors; the calibration current parameter is used for controlling the color and the brightness of the calibration picture;

and adjusting the brightness of each light source primary color according to the current correction value of each light source primary color.

Preferably, the determining the current correction value of each light source primary color according to the difference relation between the color components and the corresponding calibration current parameter of the light source primary color includes:

determining a target component from each color component, and obtaining a first reverse offset value corresponding to each light source primary color according to the difference value between each color component and the target component;

obtaining a first ratio value corresponding to each light source primary color according to the ratio of the coordinate values of each calibration current parameter to the color space;

and obtaining current correction values corresponding to the light source primary colors according to the product of the first proportional value and the first reverse offset value corresponding to the light source primary colors.

Preferably, the target component is a minimum value in each of the color components; and said adjusting the brightness of each of said light source primaries according to said current correction value for each of said light source primaries comprises: subtracting the corresponding current correction value from the first light source current output value corresponding to each light source primary color to adjust the brightness of each light source primary color.

Preferably, when the first light source current output value of any of the light source primary colors is smaller than the current correction value, the target component is a maximum value of the color components, and the adjusting the luminance of each of the light source primary colors according to the current correction value of each of the light source primary colors includes: adding the first light source current output value corresponding to each light source primary color to the corresponding current correction value to adjust the brightness of each light source primary color.

Preferably, the obtaining the first ratio value corresponding to each primary color of the light source according to the ratio of the coordinate values of each calibration current parameter to the color space includes: and obtaining a first ratio value corresponding to each light source primary color according to the ratio of each calibration current parameter to the maximum value of the color space.

Preferably, the calibration picture includes a white area, and determining the color component of each primary light source color in the calibration picture from the first captured image includes: color components of respective light source primary colors are determined from within the white region in the first captured image.

Preferably, the periphery in the calibration picture includes a plurality of identification patterns, and the determining the color component of each light source primary color in the calibration picture from the first captured image includes: identifying the identification patterns in the first photographed image, and determining color components of each light source primary color in an area between a plurality of the identification patterns.

Preferably, before the calibration picture is projected to the target projection surface to obtain the first shot image including the calibration picture, white balance correction is performed on the projection picture, and the second light source current output value of each light source primary color after the white balance correction is used as the calibration current parameter.

In a second aspect, the present invention discloses a projection device, comprising a processor and a memory, wherein the memory stores a computer program, and the computer program is readable by the processor to be executed to implement the color correction method of the projection screen according to the first aspect.

In a third aspect, the present invention discloses a storage medium having a computer program stored therein, wherein the computer program is configured to be executable by a processor to perform the color correction method of a projection screen as described in the first aspect.

Compared with the prior art, the invention has the beneficial effects that: the invention discloses a color correction method and projection equipment of a projection picture, which projects a calibration picture to a target projection plane, shoots an image containing the calibration picture, then determines the color component of each light source primary color based on the shot image, then determines the current correction value of each light source primary color according to the difference value between the color components of each light source primary color and the calibration current parameter, and finally adjusts the brightness of each light source primary color based on the current correction value, thereby providing a method capable of correcting the projection effect according to the projection environment, effectively improving the projection display effect on the color target projection plane, maximally reducing the difference of the projection equipment relative to the white target projection plane in the environments, and greatly improving the projection picture display effect in the practical use environment.

Drawings

FIG. 1 is a flowchart of a method for color correction of a projection screen according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the hardware components of the projection device;

FIG. 3 is a coverage comparison schematic of a field of view area of a camera of a projection device and a projection display area of a bare engine;

FIG. 4 is a schematic illustration of a calibration screen;

fig. 5 is a schematic drawing of extracting the center area of the calibration picture.

Detailed Description

The following describes embodiments of the present invention in detail. It should be emphasized that the following description is merely exemplary in nature and is in no way intended to limit the scope of the invention or its applications.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element. In addition, the connection may be for both the fixing action and the circuit/signal communication action.

It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are merely for convenience in describing embodiments of the invention and to simplify the description by referring to the figures, rather than to indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless explicitly defined otherwise.

As shown in fig. 1, a first embodiment of the present invention discloses a color correction method for a projection screen, which includes the following steps:

s1: projecting a calibration picture to a target projection surface to obtain a first shooting image containing the calibration picture;

in some embodiments, before the step S1, a white balance correction is performed on the projection screen, and the second light source current output value of each light source primary color after the white balance correction is used as the calibration current parameter. The primary light source colors depend on the color of the light source in the projection device light engine, which typically includes a red light source, a green light source, and a blue light source, with the respective primary light source colors being red, green, and blue. The step of correcting the white balance of the projection picture can be executed before the projection equipment leaves the factory, and the method of correcting the white balance is to make the projection equipment project the projection picture to an ideal white target projection plane; then, each color component of a projection picture on a white target projection surface is obtained through an image pickup module, wherein the range of the color component is 0-255, wherein 0 is the lowest brightness, and 255 is the highest brightness; and adjusting the second light source current output value of each light source in the optical machine to control the duty ratio of each color component in the projection picture until the color components of three colors in the projection picture area obtained from the image pickup module are the same, thereby realizing white balance correction, and recording the second light source current output value of each light source as a corresponding calibration current parameter when the projection equipment projects the calibration picture.

S2: determining color components of primary colors of each light source in a calibration picture from a first shooting image;

in some embodiments, the calibration screen includes a white area, and the step S2 includes: the color component of each primary light source color is determined from within the white region in the first captured image.

In some embodiments, referring to fig. 4, the calibration frame includes a plurality of identification patterns around, and step S2 includes: identifying the identification patterns in the first captured image, and determining color components of the primary colors of each light source in areas between the plurality of identification patterns. Wherein the areas between the plurality of identification patterns are preferably white areas. The identification patterns are common patterns such as two-dimensional codes, checkerboards and the like which can be quickly identified by an image algorithm. The other areas of the calibration picture are white areas controlled by calibration current parameters. In one embodiment, the number of the identification patterns may be four, and the identification patterns are respectively distributed near four vertices in the calibration frame, and a central area exists between the four identification patterns, where the x-coordinate and the y-coordinate of any pixel in the central area are different from the x-coordinate and the y-coordinate of any identification pattern, and the central area is the aforementioned white area, and reference may be made to the central area 300 in fig. 5.

S3: determining a current correction value of each light source primary color according to the difference relation between the color components and the corresponding calibration current parameters of the light source primary colors; the calibration current parameter is used for controlling the color and the brightness of the calibration picture;

in a further embodiment, step S3 specifically includes:

s31, determining a target component from each color component, and obtaining a first reverse offset value corresponding to each light source primary color according to the difference value between each color component and the target component;

s32, obtaining a first ratio value corresponding to each light source primary color according to the ratio of the coordinate values of each calibration current parameter to the color space;

for example, the coordinate values of the RGB three colors in the color space are 0 to 255, and the maximum value of the corresponding color space is 255. In a specific embodiment, in this step, a first ratio value corresponding to each primary color of the light source is obtained according to the ratio of each calibration current parameter to the maximum value of the color space. Alternatively, the first example ratios corresponding to the primary colors of the light sources may be obtained according to the ratios of the calibration current parameters to the same but non-maximum values in the color space, such as 230, 240, 250, etc.

S33, obtaining a current correction value corresponding to each light source primary color according to the product of the first proportional value and the first reverse offset value corresponding to each light source primary color.

S4: and adjusting the brightness of each light source primary color according to the current correction value of each light source primary color.

In some embodiments, the target component is determined as the minimum value of the color components in step S31; step S4 at this time includes: the corresponding current correction value is subtracted from the first light source current output value corresponding to each light source primary color to adjust the brightness of each light source primary color.

Further, when the first light source current output value of any light source primary color is smaller than the current correction value, the target component is the maximum value among the color components, and step S4 includes: the first light source current output value corresponding to each light source primary color is added with the corresponding current correction value to adjust the brightness of each light source primary color.

The color correction method of the projection screen disclosed in the first embodiment of the present invention is described in detail below with reference to specific embodiments.

Taking an optical machine based on the DMD (Digital Micromirror Devices, digital micro-mirror device) technology as an example, light source light rays emitted by three light sources of RGB respectively irradiate on a DMD imaging module after light path design and are modulated and reflected by a large number of micro-mirrors in the light source light rays to form image light rays, and then the image light rays are amplified by a projection lens and then emitted to a target projection surface. According to the principle of three primary colors, a certain proportion of RGB light rays are collected together to prepare light rays with any color. Projection devices are typically designed for use on standard white screens, such as projecting a white screen onto a standard white screen, where the human eye sees a white projected image; but if the target projection surface is not purely white, but light blue, the picture seen by the human eye will be a light blue picture. The invention is based on the situation existing in the prior art, and can still display the original projection color when the projection device projects to the color-cast target projection surface by reducing the current of part of light sources or improving the current of the other part of light sources.

Taking the projection device shown in fig. 2 and including a main control board 11, a camera 12 and an optical machine 13 as an example, the optical machine 13 adopts three primary color light sources of RGB, the camera 12 is connected with the main control board 11 through a data line, and the optical machine 13 is connected with the main control board 11; as shown in fig. 3, the field of view area of the camera 12 completely covers the projection display area, so that a calibration picture can be taken. The following describes a color correction method applied to a projection screen of the projection apparatus, wherein step S1 specifically includes the following steps:

a1: the user sends a wall projection color correction command to the main control board 11 through the input device;

a2: the main control board 11 sets the light engine 13 to display in a standard brightness and color temperature mode by a command so that the light engine 13 can collect its offset based on a standard color output.

A3: the main control board 11 controls the optical machine 13 to project a calibration picture according to preset calibration current parameters corresponding to primary colors of each light source, wherein the calibration picture is a pure white background and can at least comprise one identification pattern, and the identification pattern can be a two-dimensional code, for example. In other embodiments, the calibration screen may be a solid white screen.

As shown in fig. 4, in order to facilitate region extraction, in this embodiment, 4 two-dimensional codes 200 are arranged around the calibration screen 100, and then the positions of the central regions between the four two-dimensional codes 200 are extracted by a program.

A4: the main control board 11 notifies the camera 12 of the acquisition of the picture, and obtains a first photographed image including the calibration picture.

A5: identifying the two-dimensional code 200 through a two-dimensional code program, and extracting the position of the two-dimensional code 200; and then the sample area is extracted based on the position of the two-dimensional code 200.

In this embodiment, by setting the two-dimensional code 200 around the calibration frame 100 and extracting the central area 300 of the calibration frame 100 based on the position of the two-dimensional code 200, it is able to ensure that the image of the central area 300 of the calibration frame 100 is accurately captured, and then the central area 300 of the calibration frame 100 is used as a sample area to determine parameters, so that the acquired parameters can be more accurate, and the situation that a scene outside the optical machine frame is acquired when there is a position deviation between the assembly of the camera 12 and the optical machine 13 is avoided, resulting in an error in calculation, especially in a side-projection use scene after trapezoidal correction.

The step S2 specifically comprises the following steps:

a6: an RGB average of the sample area is calculated. The average values of RGB in the sample area correspond to the color components of the primary colors red, green and blue of the light source respectively.

The step S3 specifically comprises the following steps:

a7: the current correction value of the RGB lamp of the light engine 13 is calculated based on the RGB average value of the sample area.

Step S4 then comprises:

a8: the main control board 11 adjusts the output power of the RGB lamp of the light machine according to the current correction value of the RGB lamp of the light machine 13.

Based on the electrical characteristic difference of the light sources, the brightness of the light sources in different batches can be different under the same current and voltage conditions, so that the light source currents of the corresponding light source primary colors can be different when different projection devices project calibration pictures with the same color and brightness. In this example, the projection device performs white balance correction by using a color temperature meter when leaving the factory, so as to find a set of current output values of the light sources to mix light of R, G, B light sources into white light. Based on the characteristic difference of the electrical appliances, the RGB light source current values corresponding to the light source current output values measured by different projection devices under the condition of the same white calibration picture are different, and the values of the three are supposed to be consistent under ideal conditions; the corrected RGB light source current output value may be stored inside the projection device as a calibrated current parameter of the optomachine to be obtained by command acquisition. The light source includes an LED light source and a laser light source, and an example of the LED light source will be described below.

The following are two correction calculation methods for calculating the current correction value of the RGB lamp of the light engine and adjusting the output power of the RGB light source of the light engine in the specific example:

for example, when the wall surface is simply bluish, one method is to control the light source current output of the red and green light sources in the optical machine to be unchanged, and reduce the light source current output of the blue light source, namely reduce the output brightness of the blue light source; when the wall surface is bluish green, the light source current output of the red light source in the optical machine is controlled to be unchanged, and the light source current output of the green and blue light sources is reduced, namely the light source output brightness of the blue and green light sources is reduced, so that a projection picture on the wall surface can be white in white calibration. In another method, when the wall surface is simply blue, the light source current output of the red light source and the green light source in the optical machine is controlled to be increased, and the light source current output of the blue light source is kept unchanged, namely the output brightness of the red light source and the green light source is increased. Two correction methods include:

a. current reduction method: the color correction of the projection picture is realized by reducing the brightness of the LED lamp beads corresponding to the color of the background wall surface.

a1: wall face reverse RGB value extraction;

the method for extracting the wall face reverse RGB value comprises the following steps:

a11: projecting a calibration picture to a target projection surface, such as a wall surface, then shooting to obtain a first shooting image containing the calibration picture, and calculating the difference value between each color component of the wall surface and the pure white RGB component from the white area of the calibration picture in the first shooting image:

rev_wall_r＝255-WALL_R；

rev_wall_g＝255-WALL_G；

rev_wall_b＝255-WALL_B。

wherein WALL_ R, WALL _ G, WALL _B is the color component of the three light source primary colors respectively corresponding to red, green and blue.

a12: determining reference difference components of the RGB three lamps:

in the method, the maximum value of the RGB component difference value of the wall surface distance pure white is used as a reference difference component of three RGB lamps:

rev_wall_max＝max{rev_wall_r,rev_wall_g,rev_wall_b}；

based on the reference difference components of the three light source primary colors of RGB, the offset of each lamp of RGB on the basis of the maximum value component can be obtained.

a13: calculating a first reverse offset value of the wall surface RGB component:

offset_wall_r＝WALL_R+rev_wall_max-255；

offset_wall_g＝WALL_G+rev_wall_max-255；

offset_wall_b＝WALL_B+rev_wall_max-255；

the steps a11 to a13 can be simplified as follows: firstly, determining a target component from wall RGB components: wal_min=min { wal_r, wal_g, wal_b }; and obtaining a first reverse offset value corresponding to the wall RGB components according to the difference value between the color components of the wall RGB three light source primary colors and the target component:

offset_wall_r＝WALL_R-WALL_min；

offset_wall_g＝WALL_G-WALL_min；

offset_wall_b＝WALL_B-WALL_min；

a2: light source reverse RGB value extraction;

extracting the light source reverse RGB values comprises the steps of:

a21: calculating a first proportional value of a maximum value of the light source current relative to the color space of the wall surface:

ratio_led_r＝LED_R/255；

ratio_led_g＝LED_G/255；

ratio_led_b＝LED_B/255；

the LED_ R, LED _ G, LED _B is respectively a calibration current parameter for modulating the color of a white area of a calibration picture by three light sources of red, green and blue in the optical machine; 255 in the denominator is the maximum of the three colors in the color space.

a22: calculating second reverse offset values of the light source current RGB components, and taking the second reverse offset values of the light source current RGB components as current correction values of the light source current RGB components respectively:

offset_led_r＝offset_wall_r*ratio_led_r；

offset_led_g＝offset_wall_g*ratio_led_g；

offset_led_b＝offset_wall_b*ratio_led_b；

finally, on the wall surface with color cast, the current value of the RGB light source of the optical machine is as follows:

SET_LED_R＝LED_R-offset_led_r；

SET_LED_G＝LED_G-offset_led_g；

SET_LED_B＝LED_B-offset_led_b；

in this way, the projected picture seen by the user on the target projection surface with color cast will return to a pure white picture.

When the projection device projects a picture subsequently, the corresponding offset_led_r, offset_led_g and offset_led_b are subtracted from the light source current output values of each color in the optical machine, and are positive numbers, and the main control board sets the output power of the RGB lamp according to the calculated current values so as to realize the adjustment of the brightness of the RGB lamp, and finally realizes the color correction of the projection picture, so that the projection picture projected on the target projection surface with color cast can show real colors.

In some cases, since the light source current output values of the individual color light sources are not enough to subtract the corresponding offset_led_r, offset_led_g, offset_led_b in some frames, the frames may not be completely corrected in place, and the colors of the frames displayed finally may have larger deviations. Therefore, when this is the case, the current boosting method described below can be adopted, so that the color deviation can be effectively eliminated.

b. Current boosting method: the color correction of the projection picture is realized by improving the brightness of the LED lamp beads corresponding to the complementary colors of the background wall colors.

b1: wall face reverse RGB value extraction:

the method for extracting the wall face reverse RGB value comprises the following steps:

b11: projecting a calibration picture to a target projection surface, such as a wall surface, then shooting to obtain a first shooting image containing the calibration picture, and calculating the difference value between each color component of the wall surface and the pure white RGB component from the white area of the calibration picture in the first shooting image:

rev_wall_r＝255-WALL_R；

rev_wall_g＝255-WALL_G；

rev_wall_b＝255-WALL_B；

b12: determining reference difference components of the RGB three lamps:

in the method, the minimum value of the difference value of the RGB components of the wall surface distance pure white is used as the reference difference value component of the RGB three lamps:

rev_wall_min＝min{rev_wall_r,rev_wall_g,rev_wall_b}；

based on the reference difference components of the three light source primary colors of RGB, the offset of each RGB lamp on the basis of the minimum component can be obtained.

b13: calculating a first reverse offset value of the wall surface RGB component:

offset_wall_r＝WALL_R+rev_wall_min-255；

offset_wall_g＝WALL_G+rev_wall_min-255；

offset_wall_b＝WALL_B+rev_wall_min-255；

the steps b11 to b13 can be simplified as follows: firstly, determining a target component from wall RGB components: wal_max=max { wal_r, wal_g, wal_b }; and obtaining a first reverse offset value corresponding to the wall RGB components according to the difference value between the color components of the wall RGB three light source primary colors and the target component:

offset_wall_r＝WALL_R-WALL_max；

offset_wall_g＝WALL_G-WALL_max；

offset_wall_b＝WALL_B-WALL_max；

b2: light source reverse RGB value extraction:

extracting the light source reverse RGB values comprises the steps of:

b21: calculating a first proportional value of the light source current relative to the maximum value of the wall color space:

ratio_led_r＝LED_R/255；

ratio_led_g＝LED_G/255；

ratio_led_b＝LED_B/255；

b22: calculating second reverse offset values of the light source current RGB components, and taking the second reverse offset values of the light source current RGB components as current correction values of the light source current RGB components respectively:

offset_led_r＝offset_wall_r*ratio_led_r；

offset_led_g＝offset_wall_g*ratio_led_g；

offset_led_b＝offset_wall_b*ratio_led_b；

finally, on the wall surface with color cast, the current value of the RGB light source of the optical machine is as follows:

SET_LED_R＝LED_R+offset_led_r；

SET_LED_G＝LED_G+offset_led_g；

SET_LED_B＝LED_B+offset_led_b；

the corresponding offset_led_r, offset_led_g and offset_led_b are added to the RGB light source current values of other colors of each pixel, and are positive numbers, and the main control board sets the output power of the RGB lamp according to the calculated current values so as to realize the brightness adjustment of the RGB lamp, and finally realizes the color correction of a projection picture, so that the projection picture projected on a target projection plane with color cast can show real colors.

In practical application, the two methods (a current reduction method and a current lifting method) can be replaced in real time according to practical situations, for example, an image processor defaults to adopt the current reduction method, and when a certain picture cannot correct color deviation by the current reduction method, the current of the picture adopts the current lifting method; in addition, only one method can be selected: and acquiring current values corresponding to the colors of the light sources corresponding to each frame of picture of the appointed video file, and adopting a current reduction method when finding that more than half of pictures in the video file adopt the current reduction method, wherein the current reduction method can be adopted when the whole video file is played, or adopting a current lifting method.

In the embodiment of the invention, the camera is used for collecting the color of the projection area of the target projection surface, the light source of the projection equipment is adjusted through the algorithm, and the brightness of the corresponding light source primary colors is increased or reduced, so that the projection effect is corrected according to the environment; therefore, the projection display effect can be effectively improved on the color projection wall surface or curtain, and the difference of the projection equipment relative to the white projection surface in the environments is reduced to the maximum extent.

The second embodiment of the present invention also discloses a projection device, which includes a processor and a memory, wherein the memory stores a computer program, and the computer program can be read by the processor to execute the steps of the color correction method for the projection screen in the first embodiment.

The third embodiment of the present invention discloses a storage medium in which a computer program is stored, wherein the computer program is configured to be executable by a processor to perform the steps of the color correction method for a projection screen in the first embodiment.

Alternatively, the storage medium may include, but is not limited to: a usb disk, a Read-Only Memory (ROM), a random access Memory (RandomAccess Memory, RAM), a removable hard disk, a magnetic disk, or an optical disk, or other various media capable of storing a computer program.

The background section of the present invention may contain background information about the problem or environment of the present invention rather than the prior art described by others. Accordingly, inclusion in the background section is not an admission of prior art by the applicant.

The foregoing is a further detailed description of the invention in connection with specific/preferred embodiments, and it is not intended that the invention be limited to such description. It will be apparent to those skilled in the art that several alternatives or modifications can be made to the described embodiments without departing from the spirit of the invention, and these alternatives or modifications should be considered to be within the scope of the invention. In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "preferred embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction. Although embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the scope as defined by the appended claims.

Claims (10)

1. A color correction method for a projection screen, the method comprising:

projecting a calibration picture to a target projection surface, and obtaining a first shooting image containing the calibration picture;

determining color components of primary colors of each light source in the calibration picture from the first shooting image;

determining a current correction value of each light source primary color according to the difference relation between the color components and the corresponding calibration current parameters of the light source primary colors; the calibration current parameter is used for controlling the color and the brightness of the calibration picture;

and adjusting the brightness of each light source primary color according to the current correction value of each light source primary color.

2. The method of claim 1, wherein determining the current correction value for each of the light source primary colors based on the difference relationship between the color components and the corresponding nominal current parameters for the light source primary colors comprises:

determining a target component from each color component, and obtaining a first reverse offset value corresponding to each light source primary color according to the difference value between each color component and the target component;

obtaining a first ratio value corresponding to each light source primary color according to the ratio of the coordinate values of each calibration current parameter to the color space;

and obtaining current correction values corresponding to the light source primary colors according to the product of the first proportional value and the first reverse offset value corresponding to the light source primary colors.

3. The method of claim 2, wherein the target component is a minimum value in each of the color components; said adjusting the brightness of each of said light source primaries according to said current correction value for each of said light source primaries comprises: subtracting the corresponding current correction value from the first light source current output value corresponding to each light source primary color to adjust the brightness of each light source primary color.

4. A method according to claim 3, wherein said first light source current output value of any of said light source primary colors is less than said current correction value, said target component being the maximum value of each of said color components, said adjusting the brightness of each of said light source primary colors based on said current correction value of each of said light source primary colors comprising: adding the first light source current output value corresponding to each light source primary color to the corresponding current correction value to adjust the brightness of each light source primary color.

5. The method according to claim 2, wherein obtaining the first ratio value corresponding to each primary color of the light source according to the ratio of the coordinate values of each calibration current parameter to the color space comprises: and obtaining a first ratio value corresponding to each light source primary color according to the ratio of each calibration current parameter to the maximum value of the color space.

6. The method of claim 1, wherein the calibration frame includes a white region, and wherein determining color components of primary colors of light sources within the calibration frame from the first captured image includes: color components of respective light source primary colors are determined from within the white region in the first captured image.

7. The method of claim 1 or 6, wherein the periphery within the calibration frame includes a plurality of identification patterns, and wherein determining color components of the primary colors of the light sources within the calibration frame from the first captured image includes: identifying the identification patterns in the first photographed image, and determining color components of each light source primary color in an area between a plurality of the identification patterns.

8. The method according to claim 1, wherein before the calibration picture is projected onto the target projection surface to obtain the first captured image including the calibration picture, a white balance correction is performed on the projection picture, and the second light source current output value of each light source primary color after the white balance correction is used as a calibration current parameter.

9. A projection device comprising a processor and a memory, the memory having stored therein a computer program readable by the processor for execution to implement the method of color correction of a projected picture as claimed in any one of claims 1 to 8.

10. A storage medium having a computer program stored therein, wherein the computer program is arranged to be run by a processor to perform the method of color correction of a projected picture as claimed in any one of claims 1 to 8.