Image Color Conversion#

This chapter describes implementation of image processing functions that perform different types of image color conversion. The oneIPL supports the following image color conversions:

  • Color models conversion

  • Conversion from color to gray scale and vice versa

  • Different types of format conversion:

    • from pixel-order to planar format and vice versa

    • changing number of channels or planes

    • changing sampling format

    • altering order of samples or planes

  • Gamma correction

  • Reduction from high bit resolution color to low bit resolution color

  • Intensity transformation using lookup tables

  • Color twist

  • Color keying

All oneIPL color conversion functions perform point operations on pixels of the source image. For a given destination pixel, the resultant channel values are computed using channel values of the corresponding source pixel only, and not involving any neighborhood pixels. Thus, the rectangular region of interest (ROI, see Regions of Interest in oneIPL) used in function operations may extend to the size of the whole image.

This chapter starts with introductory material that discusses color space models essential for understanding of the oneIPL color conversion functions.

For more information about color spaces and color conversion techniques, see [Jack01], [Rogers85], and [Foley90].