The Effect of Image Content on Color Difference Perceptibility

Considerable work has been conducted regarding the perceptibility of color differences for simple images such as uniform color patches. From this work comes such tools as the MacAdam ellipses. Less is known regarding color difference perceptibilitywhen complex images are involved. However, the proliferation ofdesktop publishing equipment and the increasingly technically elegant accompanying software makes questions around this topic bothmore facile andmore relevant to study. The information that could be gleanedmay be useful for the design of color printer algorithms or other imaging systems. The objective of this research was to examine the impact of image content, if any, on the perceptibility of color differences. Psychophysical experimentation was conducted to determine if image content is a significant factor in color difference perceptibility. Portraits and nature scenes containing "memory colors" or colors for which observers have some preconceptions, images ofman-made objects void ofmemory colors, andmosaic images containing no recognizable image content were examined in the experimenta tion. Four different mosaic images, each composed ofpatches of a given size, were also included to investigate the effect of the size of image elements making up the image content on color difference perceptibility. The experimental results suggest that the size of elements contained in the image affected the perceptibility of color differences while the presence ofmemory colors or recognizable image content had no conclusive effect.