imag_improve_rgb

代码说明：

  This is a two stage method in which at first image RGB compensated and then converted to YCbCr to normalise overall illumination of image.Its cascaded implementation of section 2.A of paper "A FAST SKIN REGION DETECTOR" by Phil Chen, Dr.Christos Greecos, ESC Division Research 2005,and section 2.1 of paper "Simple and Accurate Color Face Detection Algorithm in Complex Background" by YUI TING PAI et al. ICME 2006 . Please go through those papers for more details.