The fact is one of the most important code in image processing is filtering, and filters comes in many forms. The following is a filter using RGB Color Space, and below shows RGB Color Space, filtered image with certain values of RGB, and a method show to how to approximate the values needed for RGB filtering to detect one Faces for example.
Looking forward to see your contributions, feel free to contact me anytime :).
*RGB COLOR SPACE
*Filtered image with certain values of RGB
*Knowing approximate range color using Paint