Research On Brightness Equalization Algorithm Of Color Image In Low Illumination Environment

Obtained under low illumination environment image contains very low intensity of illumination of LLL image and local highlights the uneven illumination of the image,they usually have whole or partial low brightness,the characteristics of the image information in short supply,then need to deal with the effective means to enhance processing,and the image enhancement algorithm for the two type at present these algorithms have their own problems.Therefore,this paper focuses on the enhancement algorithm for low-light image and uneven illumination image in low illumination image,and designs an improved algorithm according to the problems encountered in the research process.The specific research work is as follows:In order to solve the problems of low light level image enhancement,such as insufficient enhancement,noise amplification,color distortion,blur and halo artifact,a low light level color image enhancement algorithm with adaptive brightness adjustment was proposed.This algorithm is based on multi-frame sequence processing method.Firstly,multi-frame images are taken consecutively for low illumination scenes,and the adaptive gamma brightness correction is performed on them.And then to convert more brightness adjusted images to YUV color space for two kinds of parallel processing,one processing is to extract component grouping Y channel based on weight adjustment of blind source separation of second-order blind identification of noise reduction,the another processing is to extract the Y-channel components after frame averaging and carry out structural similarity matching with the Y-channel components denoised by multiple blind source separation to select the best matching Y-channel components;Then the best Y-channel components were adjusted based on Peel growth curve and recombined with the U and V channel components processed by frame averaging.Finally,the reconstructed image is converted back to RGB space and linear transformation with limited maximum value is carried out to obtain a color image with significantly improved visual effect.This algorithm can improve the noise processing,brightness equalization and detail restoration of low light level image.In order to solve the problem of insufficient brightness equalization and insufficient local detail enhancement in traditional enhancement algorithms,a brightness equalization algorithm based on region division was proposed.This algorithm deals with single frame image.Firstly,color RGB images were input and converted into HSV color space.Separate the brightness V-channel brightness and calculate its mean value.If the mean value is less than the threshold value,three parallel processing methods are performed to obtain region division,neighborhood information and illumination components,and then the adaptive gamma correction parameter is constructed.If the mean brightness value is greater than the set limited threshold,the image is inverted so that the mean value is less than the set limited threshold and the above operations continue.Then the gamma correction parameter is used to correct the image,and finally the image color is restored according to the original image.This method can solve the problem of uneven illumination distribution caused by environmental illumination intensity,illumination Angle or shooting conditions,and improve the image details more obviously.