CLHAE image enhancement method based on gray level compression

Abstract

The invention discloses a CLHAE image enhancement method based on gray level compression. The method comprises: converting a current RGB color space image into a YUV color space image, and extractingeach initial pixel value of image brightness Y; performing uniform and non-overlapping partitioning, gray level compression, histogram statistics, contrast limitation, and histogram equalization on the image brightness Y, to obtain a gray level mapping table of each block; performing bilinear interpolation algorithm calculation on the image brightness Y, to obtain each adjusted pixel value of theimage brightness Y; calculating a color conversion ratio between each initial pixel value of the image brightness Y and the adjusted pixel value, and applying to the current RGB color space image, tooutput a new RGB color space image. The method can improve processing efficiency, expand a dynamic range of an image and enhance contrast of the image on the basis of keeping the color ratio of an original image, thereby realizing fast and efficient image enhancement effect.

Description

technical field [0001] The present invention relates to the technical field of image processing, and more specifically, to a CLHAE (Contrast Limited Adaptive Histogram Equalization, Contrast Limited Adaptive Histogram Equalization) image enhancement method with color preservation and grayscale compression. Background technique [0002] With the development of society, automobiles are becoming more and more indispensable in daily life as a means of transportation, and corresponding vehicle-mounted products are also emerging, among which the vehicle-mounted image products are the most prominent. In practical applications, images collected by vehicle-mounted products often have low contrast and low definition due to equipment, ambient brightness, image compression methods, etc., which is not conducive to subsequent processing. In order to improve these defects, it is necessary to perform image enhancement on such images. [0003] Traditional image enhancement methods are divid...

AI Technical Summary

Problems solved by technology

For the whole image, the gray level of the image has been expanded, but for the original image with a "uniform" gray level distribution, the brightness of the image processed by these methods is relatively smooth, and the image appears "whitened", that is, the contrast has not been obtained. promote

Therefore, none of the above image enhancement methods can obtain a clear and satisfactory image enhancement effect.

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