12-04-2012, 01:28 PM
A NOVEL 3-D COLOR HISTOGRAM EQUALIZATION METHOD WITH UNIFORM 1-D GRAY SCALE HISTOGRAM
ABSTRACT:
The majority of color histogram equalization methods do not yield uniform histogram in gray scale. After converting a color histogram equalized image into gray scale, the contrast of the converted image is worse than that of an 1-D gray scale histogram equalized image.
We propose a novel 3-D color histogram equalization method that produces uniform distribution in gray scale histogram by defining a new cumulative probability density function in 3-D color space.
Test results with natural and synthetic images are presented to compare and analyze various color histogram equalization algorithms based upon 3-D color histograms. We also present theoretical analysis for nonideal performance of existing methods.