Study Of Appearance Evaluation Based On Texture Characteristics

Color and texture are the important parts of object appearance. The different textures would affect the visual color difference significantly when the colors of the object appearances are the same or similar. Especially in the textile industry, the texture structure has obvious effects on the visual color perceptions. But the existing color appearance model, such as CIECAM02, cannot satisfactorily predict the color appearance of the samples with textures. In order to properly describe the appearance of the textiles, a series of psychophysical experiments were specially designed to derive the most important visual properties for textiles and the computational model for each visual property, which is of great significance to the various applications of textiles.To investigate the human visual perception for the textural features of textiles,15parameters representing textile properties were evaluated in this study via the psychophysical method of categorical judgment with the surface samples presented in a light booth and simulated samples on a display, respectively. The analysis of experimental data indicates that the visual perception of textiles can be expressed by the3properties of directionality, smoothness and warmth, and directionality and smoothness properties depend on texture structure while the warmth property are highly related to the colors. The textiles with large primitive elements have high directionality and coarseness, while the textiles with unobvious primitive elements exhibit the properties of randomness and smoothness. The visual perception of the warmth property increases slightly for coarser samples when they have similar color. Meanwhile, the visual evaluations for the15properties of the surface samples coincide well with those of display samples.Based on the psychophysical method of pair comparison, three models were built respectively for the three principal visual properties. The experimental results indicate that the directionality property correlates well with the Fourier spectral distribution, i.e., when the placement rules change, its evaluation varies and is proportional to the log value of the computational directionality. The coarseness property depends on the spatial frequency and depth information, and the corresponding visual perception decreases when the display sample is made smoother through Gaussian blur. The chroma and hue of the display textile sample have a vital impact on the assessments for the warmth property, and the red and yellow samples are visually warmer than the blue and purple ones.Finally, on the basis of summarizing the research of this thesis, the prospects of the future study were also proposed.