When I'm searching on the Internet for the Image Processing Algorithm, I found this useful article, so I copy it to my blog. Thanks the Author of nbdtech.com.
I needed a way to test if a background color is light or dark in order to choose an appropriate text color (black on light colors and white on dark colors), you can find yourself in the same problem if you try to convert an image to grayscale.
I found many approaches that didn’t work well, I’ll describe them and the problems I discovered...
