Image processing basics 1.0

I did not write a program for a long time, and it was unclear how many items were found this time.

First, the format and representation of the image. BMP, JPG, Tiff, GIF,... so many formats, compressed, not compressed. Let alone. I only select BMP. This is a big problem. There is a big difference between 8-bit and 24-bit. Previously, only grayscale images were used. Everything was simple. However, it is troublesome to get a 24-bit color image. RGB, these three channels are already in the dark. There are so many YUV, lab,... so many color spaces.

Statistical Features of images, such as histograms, brightness, and contrast. The items that are easy to use in gray scale are different in color images. Do I calculate each channel or use a value. The histograms in Photoshop include brightness, red, green, and blue. How can we get the brightness?

I always thought that as long as I knew how it would work, but the accuracy of writing programs was not very rough. What is it. The concept is too unclear. It is necessary to make a good supplement to the image.