Chapter 3. Color and Color Imagery

Summary

In addition to shape, texture and other low-level image features, color information is an important feature which has been successfully used in many image processing applications such as object recognition, image matching, context based image retrieval, computer vision, color image compression, etc. In this chapter, we briefly describe the principles behind the perception of colors by human visual system and then describe the important color space transformation techniques suitable for digital image processing. We also introduce in this chapter a new area of development in color image processing, popularly known as color interpolation. Due to the cost and packaging consideration, in digital imaging devices such as a digital cameras, the image color is captured in a sub-sampled pattern. Typically each pixel in the captured raw image contains only one of the three primary color components, R (Red), G (Green), or B (Blue). The methodology to recover or interpolate these missing color components is popularly known as “color interpolation” or “color demosaicing”. We describe various non-adaptive and adaptive color interpolation algorithms and some interesting results.