|Color correction in tone mapping
|Radoslaw Mantiuk(1,3), Rafal Mantiuk(2), Anna Tomaszewska(1), Wolfgang Heindrich(2)|
|(1)Szczecin University of Technology, Szczecin, Poland|
|(2)The University of British Columbia, Vancouver, Canada|
|(3)Max-Planck-Institut fur Informatik, Saabrucken, Germany|
|An original image A) compared with three images after contrast compression. Two common color correction methods B) and C) are compared with manual color adjustment D). Existing color correction methods cannot adjust colors for large contrast compression. c - contrast compression factor, s - desaturation factor.|
Tone mapping algorithms offer sophisticated methods for mapping a real-world luminance range to the luminance range of the output medium but they often cause changes in color appearance. In this work we conduct a series of subjective appearance matching experiments to measure the change in image colorfulness after contrast compression and enhancement. The results indicate that the relation between contrast compression and the color saturation correction that matches color appearance is non-linear and smaller color correction is required for small change of contrast. We demonstrate that the relation cannot be fully explained by color appearance models. We propose color correction formulas that can be used with existing tone mapping algorithms. We extend existing global and local tone mapping operators and show that the proposed color correction formulas can preserve original image colors after tone scale manipulation.
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