Face detection theory

Face detection is a very specific case of object recognition. There are many approaches to face recognition. However, we are going to discuss the two given here:

• Segmentation based on color
• Feature-based recognition

Segmentation based on color

In this technique, the face is segmented out based on skin color. The input of this is typically an RGB image, while in the processing stage we shift it to Hue saturation value (HSV) or YIQ ( Luminance (Y), In-phase Quadrature) color formats. In this process, each pixel is classified as a skin-color pixel or a non-skin-color pixel. The reason behind the use of other color models other than RGB is that sometimes RGB isn't able to distinguish skin colors in different light conditions. This significantly...