The human skin colors of different individuals cluster
in a small region in color space provided that the images
are taken under illumination controlled environments [11].
Hence, one of the easiest and often used methods is to de-
fine skin-color cluster decision boundaries for different color
space components. Single or multiple ranges of threshold
values for each color space component are defined and the
image pixel values that fall within these predefined range(s)
for all the chosen color components are defined as skin
pixels.