Histogram equalization
When the pixel values in an image occupy all gray levels and are evenly distributed, the image has high contrast and variable tone changes, and the image looks obvious in layers and clear in details.
The purpose of histogram equalization is to map and transform the pixel values in an image, so that the gray distribution of the mapping result image is balanced. At this time, the contrast of the image is increased, and the visual sense is clearer.
void cv::equalizeHist(InputArray src,
OutputArray dst
)
src : Source 8-bit single-channel image.
dst : The destination image of the same size and type as src.
The algorithm for the above function can be described as:
(1), calculate the grayscale histogram H< of the original image src