CN103020588A - Flame detection method based on video image analysis - Google Patents

Abstract

The invention discloses a flame detection method based on video image analysis, and the core idea lies in that the aim of flame pixel identification is achieved by converting an acquired video image from an RGB color space to a CIE xyY color space, and comparing with a nominal standard flame color in terms of the distribution characteristics on a CIE xy chromaticity diagram. In addition, after conversion, CIE xyY data are simultaneously input to a flame detection module and a moving target detection module in parallel, and then binary images output by the two modules are fused to detect whether a fire occurs in a monitored scene. As flame color has relatively high definition and peculiarity in the CIE xy color space, the flame detection method has relatively high flame identification precision and a wide application range. At the same time, as the parallel processing of the flame detection module and the moving target detection module is adopted, the flame detection method has a fast speed of responding to fire detection.

Description

Flame detecting method based on video image analysis

Technical field

The present invention relates to a kind of flame detecting method based on video image analysis, especially by the analysis to pixel color feature in the video image of Real-time Collection, carry out flame detecting and alarm, belong to the technical field of intelligent fire hazard monitoring.

Background technology

Fire hazard monitoring and prior-warning device system comprise the building fire prevention in a lot of fields, and forest fire protection in the physical environment monitoring, plays very important effect.Traditional fire monitoring technology and device comprise corpuscular type smoke transducer, infrared ray and laser technology etc.The corpuscular type smoke transducer needs smoke particle to enter sensor just can cause warning, infrared ray and laser technology also need smog to block could cause warning, in addition, buildings and outdoor environment to large space, need a large amount of sensor device of layout just can reach higher monitoring coverage percentage and monitoring accuracy, cause cost to rise.

In recent years along with development and the raising of video monitoring system and Computer Vision Recognition technology, based on the fire detection system of video image analysis the trend that replaces conventional apparatus is just being arranged, especially in building fire prevention and outdoor environment are monitored.In the prior art based on the fire detection system of video image, many methods are suggested and adopt.In these methods, be divided into two main modular based on the flame detection method of video image analysis: the identification of moving target and cut apart the flame characteristic analysis.Be input to the flame characteristic analysis module through the identification of moving target and the image pixel data of dividing processing, by the features such as color, the shape of moving target and the form of beating are analyzed, and and the distinctive feature of flame analyze contrast, reach the purpose of flame identification and detection.Yet, in these methods, some algorithms adopt traditional color space for example RGB and YUV carry out the identification of flame color feature, False Rate is higher; Some algorithms are at first carried out the flame characteristic analysis, carry out moving target identification again, cause computing velocity slower, and operating cost is higher.And the other algorithm is analyzed and is detected for behavioral characteristics such as flame profiles, and algorithm framework complexity and False Rate are higher.

Summary of the invention

The objective of the invention is to overcome the deficiencies in the prior art, a kind of fire detection method based on video image analysis is provided, especially by to the analysis of pixel color feature on another color space in the video image of Real-time Collection, improve the precision of fire detection and early warning.Adopt simultaneously the mode of flame detection and moving target detection parallel processing, improve the processing speed of fire detection.

Technical scheme provided by the invention, the flame detecting method based on video image analysis comprises the steps:

Step 101: gather vedio data, the video image RGB data communication device of monitoring scene is crossed Video Image Collecting System Based obtain;

Step 103: converting video view data color space; The RGB color space conversion to CIE XYZ color space and CIE xyY color space conversion, during conversion, is turned to rgb video view data linearity first R ＇ G ＇ B ＇ data:

$R^{\′}=f_r^{-1}\left(R\right),G^{\′}=f_r^{-1}\left(G\right),B^{\′}=f_r^{-1}\left(B\right)$ Wherein

$f_r^{-1}\left(c\right)=\left\{\begin{array}{cc}{\left(\frac{c+0.055}{1.005}\right)}^{2.4}& c>0.03928\\ \frac{c}{12.92}& c\≤0.03928\end{array}\right.$

Subsequently, linearizing R ＇ G ＇ B ＇ view data is converted into CIE XYZ view data:

$\left|\begin{array}{c}X\\ Y\\ Z\end{array}\right|=\left|\begin{array}{ccc}0.412453& 0.357580& 0.180423\\ 0.212671& 0.715160& 0.072169\\ 0.019334& 0.119193& 0.950227\end{array}\right|*\left|\begin{array}{c}{R}^{\′}\\ G^{\′}\\ B^{\′}\end{array}\right|$

CIE XYZ view data is transformed into CIE xyY view data subsequently after the conversion, wherein:

$x=\frac{X}{X+Y+Z},y=\frac{Y}{X+Y+Z}$

Step 105: detect in the color space after conversion whether the target that meets the flame color feature is arranged; To change after CIE xy data and the Standard Colors data plot of each pixel of image compare, if the CIE xy coordinate points of this pixel drops in the flame region in the Standard Colors data plot, this pixel assignment is 1; If the CIE xy coordinate points of this pixel drops on outside the flame region in the Standard Colors data plot, this pixel assignment is 0; And export a width of cloth binary image, this characterization image meet the image pixel positions of flame color feature;

Step 107: detect in the color space after conversion whether moving target is arranged; Carry out detection and the judgement of moving target by CIE Y view data; Detection of Moving Objects is mainly finished by the difference that compares present image and background image, by comparing, one amplitude shift moving-target binary image MO is generated, the background image of constantly updating leaves in the background image buffer, background image is finished by difference image between statistics frame again, the frame-to-frame differences image calculation is CIE Y brightness poor of the two continuous frames image of real time video image, if continuous a few frame or in a period of time, the frame-to-frame differences image is continuously zero or is close to zero, this monitoring scene image is reliable background image, and this background image leaves in the background image impact damper and constantly is updated; And export an amplitude shift moving-target binary image, this characterization image the image pixel positions of moving target;

Step 109: the testing result of fusion steps 105 and step 107, there is dynamic flame to occur in the time of judgement, if meet the flame occurrence condition, enter step 110 and start the fire alarm device; Otherwise continue to enter step 101 and carry out Real Time Monitoring; Fusion method is binaryzation AND operation, and it all is 1 in above-mentioned two width of cloth binary images that certain pixel of present image only has simultaneously, and this pixel just can be judged as suspicious flame pixels.Further may judge to comprise the number of adding up suspicious flame pixels, reach a certain threshold value when adding up the suspicious flame pixels number of gained, detection side's rule judges that current monitoring scene has fire to occur, and produces a fire alarm signal, starts early warning system.

Step 110: start the fire alarm device.

Advantage of the present invention: adopting the video image that will gather is CIE xyY color space from the RGB color space conversion, by contrasting with the distribution characteristics of the standard flame source color of demarcating on CIE xy chromatic diagram, reaches the identification of flame pixels.CIE xy is independently linear color space of a kind of equipment, more can accurately explain color characteristic in itself.The standard flame source color has obvious distinguishing and uniqueness at CIE xy chromatic diagram.So the present invention has higher flame to detect degree of accuracy.Because the present invention adopts flame to detect and the mode of moving target detection parallel processing, fire detection operation reaction velocity is fast, wide accommodation in addition.

Description of drawings

Fig. 1 is fire detection method schematic flow sheet among the present invention.

Fig. 2 is Plays flame color of the present invention position signal in XYZ chromaticity diagram.

Fig. 3 is apparatus structure block diagram of the present invention.

Embodiment

The invention will be further described with enforcement below in conjunction with concrete accompanying drawing.

As shown in Figure 1, be fire detection method schematic flow sheet among the present invention.Step is as follows:

Step 101: gather vedio data; The video image that gathers is in from the RGB color space conversion to CIE XYZ color space and the further CIE xy color space conversion of image pretreatment module, in transfer process, because common RGB color space is non-linear space, namely passed through the Gamma correction processing, the rgb video view data of therefore obtaining at first wants linearity to turn to R ＇ G ＇ B ＇ data; Linearizing R ＇ G ＇ B ＇ view data is converted into CIE XYZ view data by the linear matrix operation, and CIE XYZ view data is transformed into CIE xyY view data subsequently after the conversion;

Step 103: converting video view data color space; To change after CIE xy data and the Standard Colors data plot of each pixel of image compare, if the CIE xy coordinate points of this pixel drops in the flame region in the Standard Colors data plot, this pixel assignment is 1; Otherwise assignment is 0, and the Output rusults of flame pixels detection module is a width of cloth binary image, this characterization image meet the image pixel positions of flame color feature.

Step 105: detect in the color space after conversion whether the target that meets the flame color feature is arranged; When carrying out the flame pixels detection, the detection of moving target and judgement are also in parallel processing.The CIE Y luminance picture data that are converted to through pretreatment module are used for carrying out detection and the judgement of moving target.Detection of Moving Objects of the present invention is mainly finished by the difference that compares present image and background image, and by comparing, an amplitude shift moving-target binary image MO is generated.The background image of constantly updating leaves in the background image buffer.Background image is finished by difference image between statistics frame again, and the frame-to-frame differences image calculation is CIE Y brightness poor of the two continuous frames image of real time video image.If continuous a few frame or in a period of time, frame-to-frame differences image are zero or are close to zero that this monitoring scene image visual is reliable background image always, this background image leaves in the background image impact damper and constantly is updated.The Output rusults of moving target detection module is an amplitude shift moving-target binary image, this characterization image the image pixel positions of moving target.

Step 107: detect in the color space after conversion whether moving target is arranged; Two width of cloth binary images of flame pixels detection module and moving target module output merge judged whether that further flame occurs in current monitoring scene.Fusion method is binaryzation AND operation, and it all is 1 in above-mentioned two width of cloth binary images that certain pixel that is to say present image only has simultaneously, and this pixel just can be judged as suspicious flame pixels.Further may judge to comprise the number of adding up suspicious flame pixels, reach a certain threshold value when adding up the suspicious flame pixels number of gained, detection side's rule judges that current monitoring scene has fire to occur, and produces a fire alarm signal, starts early warning system.

The present invention also provides a kind of flame detecting device, comprises Video Image Collecting System Based, video image analysis system, fire warning system.Wherein the video image analysis system comprises four modules: video image pretreatment module, moving target identification module, flame pixels identification module, and fire judge module.The video image analysis system is positioned at computer system, is core of the present invention, by the video image of Real-time Collection is processed and analyzed, and makes the judgement that whether has fire to occur.At first, the video image subsystem by pretreatment module to image graph as pre-service such as color space conversion, the RGB image format conversion that video acquisition is obtained is to CIE xyY color space.Pre-service also can comprise the processing such as denoising, further improves the precision and stability that flame is judged.Be input to respectively two parallel processing modules through the vedio data after the color space conversion: moving target identification module and flame pixels identification module.This parallel processing is different from traditional serial processing, can greatly accelerate processing and reaction velocity that fire is judged.The moving target identification module also comprises a frame background image buffer.The flame pixels identification module also comprises the standard flame source color data figure of prior demarcation.The fire judge module is accepted the Output rusults of moving target identification module and flame pixels identification module, makes the judgement that whether has fire to occur, and the fire alarm signal is input to fire early-warning system.

The implementation step is as follows: in step 101, the vedio data of institute's monitoring scene obtains by Video Image Collecting System Based, supposes that video image format is rgb format.Next, the video image of collection passes through step 103 from the RGB color space conversion to CIE XYZ color space and further CIE xy color space conversion; CIE XYZ color space is different from the RGB color space, and it is independently linear color space of a kind of equipment, by International Commission on Illumination last century the '20s propose and 1931 with its standardization, more can accurately explain color characteristic in itself.In the present invention, the CIE XYZ three-dimensional color space data after the conversion further are transformed into CIE xyY chrominance space, make color characteristic (form and aspect and saturation degree) further be independent of brightness.Because common RGB color space is non-linear space, has namely passed through the Gamma correction processing, the rgb video view data of therefore obtaining at first wants linearity to turn to R ＇ G ＇ B ＇ data:

$R^{\′}=f_r^{-1}\left(R\right),G^{\′}=f_r^{-1}\left(G\right),B^{\′}=f_r^{-1}\left(B\right)$ Wherein

$f_r^{-1}\left(c\right)=\left\{\begin{array}{cc}{\left(\frac{c+0.055}{1.005}\right)}^{2.4}& c>0.03928\\ \frac{c}{12.92}& c\≤0.03928\end{array}\right.$

Subsequently, linearizing R ＇ G ＇ B ＇ view data is converted into CIE XYZ view data:

$\left|\begin{array}{c}X\\ Y\\ Z\end{array}\right|=\left|\begin{array}{ccc}0.412453& 0.357580& 0.180423\\ 0.212671& 0.715160& 0.072169\\ 0.019334& 0.119193& 0.950227\end{array}\right|*\left|\begin{array}{c}{R}^{\′}\\ G^{\′}\\ B^{\′}\end{array}\right|$

CIE XYZ view data is transformed into CIE xyY view data subsequently after the conversion, wherein:

$x=\frac{X}{X+Y+Z},y=\frac{Y}{X+Y+Z}$

In step 105, carry out flame color signature analysis and detection from the CIE xy two-dimensional chromaticity view data that step 103 is converted to.This analysis and detection are by comparing to finish with the good standard flame source color data Figure 106 of prior demarcation.As shown in Figure 2, the color data of standard flame source is plotted on the CIE xy chromatic diagram, and transverse axis represents CIE x value, and the longitudinal axis represents CIE y value.Scientific research represents that flame mainly is distributed in redness and yellow area with obvious color characteristic, and this feature is especially obvious on CIE xy chromatic diagram.Color among Fig. 2 in the shape of a hoof track is visible all colourities of common people, and outside curved boundary is spectrum locus, and the oblique line Delta Region that marks is the chromaticity coordinate zone of having demarcated the standard flame source place.As shown in the figure, be distributed in the zone, the lower right corner of CIE xy chromaticity coordinate figure in the standard flame source color set, utilize this information, the vedio data of institute's monitoring scene just can carry out the flame color signature analysis.Be embodied as: to change after CIE xy data and the Standard Colors data plot of each pixel of image compare, if the CIE xy coordinate points of this pixel drops in the oblique line Delta Region among Standard Colors data Figure 106, this pixel assignment is 1; Otherwise assignment is 0.The Output rusults of step 105 is a width of cloth binary image, this characterization image meet the image pixel positions of flame color feature.

Step 107 integrating step 108 is finished detection and the judgement of moving target.The CIE Y luminance picture data that are converted to through step 103 are used for carrying out detection and the judgement of moving target.Detection of Moving Objects of the present invention is mainly finished by the difference that compares present image and background image, and by comparing, an amplitude shift moving-target binary image MO is generated:

；

Y (i wherein, j, t) be in the present image location of pixels at (i, j) the CIE Y brightness value of locating, BG (i, j, t-1) be in the previous frame background image location of pixels at (i, j) the CIE Y brightness value of locating, Threshold are judgment thresholds that prior experimental calibration obtains.The background image of constantly updating leaves in the background image buffer.Background image is finished by difference image between statistics frame again, and the frame-to-frame differences image calculation is CIE Y brightness poor of the two continuous frames image of real time video image.If continuous a few frame or in a period of time, frame-to-frame differences image are zero or are close to zero that this monitoring scene image visual is reliable background image always, simultaneously by step 108, this background image leaves in the background image impact damper and constantly is updated.The Output rusults of step 107 is an amplitude shift moving-target binary image, this characterization image the image pixel positions of moving target.

In step 109, merge from two width of cloth binary images of step 107 and step 109 output to have judged whether that further flame occurs current monitoring scene.Fusion method is binaryzation AND operation, and it all is 1 in above-mentioned two width of cloth binary images that certain pixel that is to say present image only has simultaneously, and this pixel just can be judged as suspicious flame pixels.Further may judge and comprise the number of adding up suspicious flame pixels, when the suspicious flame pixels number of statistics gained reaches a certain threshold value, detection side's rule judges that current monitoring scene has fire to occur, produce a fire alarm signal, case method enters step 110, starts prior-warning device, otherwise, implementation method reenters step 101, continues to gather current video image and monitors.

In step 110, from the alarm signal startup early warning system of step 109 output.

Fig. 2 is that standard flame source is plotted in the position signal on the CIE xy chromatic diagram, and wherein transverse axis represents CIE x value, and the longitudinal axis represents CIE y value.Scientific research represents that flame mainly is distributed in redness and yellow area with obvious color characteristic, and this feature is especially obvious on CIE xy chromatic diagram.Color among Fig. 2 in the shape of a hoof track is visible all colourities of common people, and outside curved boundary is spectrum locus, and the oblique line Delta Region that marks is the chromaticity coordinate zone of having demarcated the standard flame source place.As shown in Figure 2, be distributed in the zone, the lower right corner of CIE xy chromaticity coordinate figure in the standard flame source color set, utilize this information, the vedio data of institute's monitoring scene just can carry out the flame color signature analysis.

Fig. 3 is system and device synoptic diagram of the present invention.The present invention includes for the acquisition system 301 that gathers video image, video image analysis system 302, fire warning system 307.Wherein the video image analysis system comprises four modules: video image pretreatment module 303, moving target identification module 304, flame pixels identification module 305, and fire judge module 306.

Video Image Collecting System Based 301 can be analog video camera, can be the IP video camera also, guarantees successively to gather the current monitoring scene image and is input to video image analysis system 302.Video image analysis system 302 is positioned at computer system, the video image that gathers is processed and is analyzed, and make the judgement that whether has fire to occur.At first, video image subsystem 302 is passed through 303 pairs of image graph of pretreatment module as pre-service such as color space conversion.The RGB image format conversion that video acquisition is obtained arrives CIE xyY color space.Pre-service also can comprise the processing such as denoising, further improves the precision and stability that flame is judged.Be input to respectively two parallel processing modules through the vedio data after the color space conversion: moving target identification module 304 and flame pixels identification module 305.This parallel processing is different from traditional serial processing, can greatly accelerate processing and reaction velocity that fire is judged.Moving target identification module 304 also comprises a frame background image buffer.Flame pixels identification module 305 also comprises the standard flame source color data figure of prior demarcation.Fire judge module 306 is accepted the Output rusults of moving target identification module 304 and flame pixels identification module 305, makes the judgement that whether has fire to occur, and the fire alarm signal is input to fire early-warning system 307.Fire early-warning system 307 is conventional fire early-warning system, and the effect of fire early-warning system 307 and structure are known by the art personnel, no longer describes in detail herein.

Claims (2)

1. step 101: gather vedio data, the video image RGB data communication device of monitoring scene is crossed Video Image Collecting System Based obtain;

Step 103: converting video view data color space; The RGB color space conversion to CIE XYZ color space and CIE xyY color space conversion, during conversion, first will

The vedio data linearity turns to

Data:

Wherein

Subsequently, linearizing

View data is converted into CIE XYZ view data:

CIE XYZ view data is transformed into CIE xyY view data subsequently after the conversion, wherein:

?

Step 105: detect in the color space after conversion whether the target that meets the flame color feature is arranged; To change after CIE xyY data and the Standard Colors data plot of each pixel of image compare, if the CIE xyY coordinate points of this pixel drops in the flame region in the Standard Colors data plot, this pixel assignment is 1; If the CIE xyY coordinate points of this pixel drops on outside the flame region in the Standard Colors data plot, this pixel assignment is 0; And export a width of cloth binary image, this characterization image meet the image pixel positions of flame color feature;

Step 107: detect in the color space after conversion whether moving target is arranged; Carry out detection and the judgement of moving target by CIE Y view data; Detection of Moving Objects is mainly finished by the difference that compares present image and background image, by comparing, one amplitude shift moving-target binary image MO is generated, the background image of constantly updating leaves in the background image buffer, background image is finished by difference image between statistics frame again, the frame-to-frame differences image calculation is CIE Y brightness poor of the two continuous frames image of real time video image, if continuous a few frame or in a period of time, the frame-to-frame differences image is continuously zero or is close to zero, this monitoring scene image is reliable background image, and this background image leaves in the background image impact damper and constantly is updated; And export an amplitude shift moving-target binary image, this characterization image the image pixel positions of moving target;

Step 109: fusion steps 105And step 107Testing result, have dynamic flame to send out in the time of judgement

Give birth to, if meet the flame occurrence condition, enter step 110 and start the fire alarm device; Otherwise continue to enter step 101Carry out Real Time Monitoring; Fusion method is binaryzation AND operation, and it all is 1 in above-mentioned two width of cloth binary images that certain pixel of present image only has simultaneously, and this pixel just can be judged as suspicious flame pixels.

2. further may judge to comprise the number of adding up suspicious flame pixels, reach a certain threshold value when adding up the suspicious flame pixels number of gained, detection side's rule judges that current monitoring scene has fire to occur, and produces a fire alarm signal, starts early warning system;

Step 110: start the fire alarm device.

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