Automatic white balance method and device for a video surveillance camera

Abstract

The invention discloses an automatic white balance method and device of a video surveillance camera. The method comprises the following steps: dividing an image into a plurality of regions; in each region, computing the cumulative sum Db of the average value Mb of Cb and the absolute different value between adjacent pixels, and the cumulative sum Dr of the average value Mr of Cr and the absolute different value between adjacent pixels; in each region, carrying out Db / Mb and Dr / r to obtain a and b; arraying the value of a+b in each region from big to small and taking the regions corresponding to the first n values as reference regions; screening reference pixel points from the reference regions, wherein the reference pixel points need to satisfy two conditions at the same time; computing the three-channel average values Rave, Gave and Bave of all the reference pixel points; obtaining the RGB values of the pixel points after white balance according to the following equations: R1=Gave / Rave*R, G1=G and B1=Gave / Bave*B. The automatic white balance method and device provided by the invention have the advantages of enabling the computation of the white balance to be more accord with the standard of a grey world method, obtaining better white balance effect and being wider in application scene.

Description

technical field [0001] The invention relates to the technical field of image white balance processing, in particular to an automatic white balance method and device for a video surveillance camera. Background technique [0002] White balance is an extremely important concept in image processing. The so-called white balance (English name is White Balance), is the restoration of white objects. When we look at the vast world with our naked eyes, we have basically the same perception of the same color under different light. Color reproduction has adaptability; however, as a shooting device, such as a digital camera, it does not have the adaptability of the human eye. Under different light, due to the unbalanced output of the CCD, the color reproduction of the digital camera is distorted; the white balance is for Realize that the camera can shoot images with true colors under different light environments. [0003] In a physical sense, the gray world method assumes that the mea...

AI Technical Summary

Problems solved by technology

Because of this assumption, in fact, the principle of the grayscale world method is not very good for the situation where the color of the picture is not rich.

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