Observe The Environment Impact Of Color On Soft Proofing Image

Soft proofing is the new technology in recent years, applied more widely. As the use of display image simulating hard copy image, display settings, ambient light conditions and observe conditions will affect the soft proofing. Therefore, further studies need to do. By now, there is no mature method for evaluating image color difference. Most image evaluation using the method of objective evaluation, instead of the feeling of image color. Based on the impact of ambient light in the process of color evaluation, this research used subjective evaluation experiments, the experiment aimed at researching the difference of color evaluation under different ambient light. At the same time, discussed the color difference evaluation method which about the display images. It had some significance to determine the parameters of soft proofing environmental conditions.Image quality ultimately depends on the viewer satisfaction degree. Color calculation must be consistent with the visual sense. Therefore, image quality evaluation associated with the vision has become a new active research, color difference evaluation is important to the image color evaluation. The purpose of this research is to establish a method of calculating the image color difference, in order to be made the calculation result consistent with the visual sense, a large number of digital images was made to be the subjective experimental samples, evaluated by a psychophysical experiment, not only for much convince, but also for the establishment of relationship between subjective and objective color difference. In addition, a subjective evaluation experiment of image color difference levels and a subjective evaluation experiment of image color difference threshold were designed. Experimental subjects were shown on EIZO CG19 display under different ambient light conditions. A subjective evaluation experiment was carried out aiming at test images by a psychophysical experiment, Testing color difference resolution situation of display image under different ambient light conditions, viewing conditions on the impact of observation results was analyzed, optimal conditions and ranges of the viewing ambient light was determined.Tow kinds of light source D50 and D65 were used in this experiment, five illuminance grades of each ambient light were used, the ambient light illuminance of D50 were 20%(1.87×100lx), 40%(6.87×100lx),60%(12.2×100lx),80%(20.0×100lx) and 100%(27.6×100lx), the ambient light illuminance of D65 were 20%(2.48×100lx),40%(9.26×100lx),60%(16.6×100lx), 80%(26.4×100lx) and 100%(33.2×100lx).68 image pairs were used in the subjective evaluation experiment of image color difference levels, and 12920 data were got.296 image pairs were used in the subjective evaluation experiment of image color difference threshold, and 10080 data were got. Discussed different sense of digital images color difference under different ambient light by analyzing the evaluation data, it has some significance to applying soft proofing.