Applying Non-linear Compression to the Three-dimensional Gamut Mapping

Gamut mapping is a technique to transform out-of-gamut colors to the inside of the output device's gamut. It is essential to develop effective mapping algorithms to realize WYSIWYG (What You See Is What You Get) color reproduction. 1 We had previously found that threedimensional gamut mapping is superior to the twodimensional mapping, when we applied Mahalanobis distance as a color difference equation, such as BFD color difference formula, 2,3 However, in our previous experiments, a clipping method was used that maps all out-of-gamut colors to the surface of the gamut, and no change was made to colors inside the gamut. Since this method could possibly cause loss of gradation in an image, we had investigated non-linear compression for the three-dimensional gamut mapping in this study. The results of visual experiments indicated that preferred compression method depends on image contents. If the saturated colors that are out-of-gamut contain high frequency, a certain degree of compression was needed. On the other hand, if those colors only have gradual change with low frequency, clipping method was more preferred.

[1]  Ronald S. Gentile,et al.  A Comparison Of Techniques For Color Gamut Mismatch Compensation , 1989, Photonics West - Lasers and Applications in Science and Engineering.

[2]  Mark D. Fairchild,et al.  Psychophysical evaluation of gamut mapping techniques using simple rendered images and artificial gamut boundaries , 1997, IEEE Trans. Image Process..

[3]  Naoya Katoh,et al.  Reconsideration of CRT Monitor Characteristics , 1997, Color Imaging Conference.

[4]  Norimichi Tsumura,et al.  Color Gamut Mapping based on Mahalanobis Distance for Color Reproduction of Electronic Endoscope Image under Different Illuminant , 1997, CIC.

[5]  Roy S. Berns,et al.  Color-gamut mapping techniques for color hardcopy images , 1993, Electronic Imaging.

[6]  S. Nakauchi,et al.  Color gamut mapping based on a perceptual image difference measure , 1999 .

[7]  Mark D. Fairchild,et al.  Gamut mapping from below: Finding minimum perceptual distances for colors outside the gamut volume , 1997 .

[8]  Shin Ohno,et al.  Three-dimensional gamut mapping using various color difference formulae and color spaces , 1999, J. Electronic Imaging.

[9]  Kevin E. Spaulding,et al.  UltraColor: a new gamut-mapping strategy , 1995, Electronic Imaging.

[10]  Mark D. Fairchild,et al.  Finding constant hue surfaces in color space , 1998, Electronic Imaging.

[11]  Naoya Katoh,et al.  Gamut Mapping for Computer Generated Images (II) , 1996, CIC.

[12]  Shin Ohno,et al.  Effect of ambient light on the color appearance of softcopy images: Mixed chromatic adaptation for self-luminous displays , 1998, J. Electronic Imaging.

[13]  R. Berns,et al.  Determination of constant Hue Loci for a CRT gamut and their predictions using color appearance spaces , 1995 .