Analysis of Physical Features Affecting Glossiness and Roughness Alteration in Image Reproduction and Image Features for Their Recovery

Digital imaging can cause the perception of an appearance that is different from the real object. This study first confirmed that the glossiness and roughness of reproduced images are altered by directly comparing real and colorimetrically reproduced images (CRIs). Then, psychophysical experiments comparing real and modulated images were performed, and the physical features that influence the alteration of the real object were analyzed. Furthermore, we analyzed the image features to recover the altered glossiness and roughness by image reproduction. In total, 67 samples belonging to 11 material categories, including metals, resins, etc., were used as stimuli. Analysis of the physical surface roughness of real objects showed that the low skewness and high kurtosis of samples were associated with alterations in glossiness and roughness, respectively. It was shown that these can be recovered by modulating the contrast for glossiness and the angular second moment in the gray level co-occurrence matrix for roughness, reproducing perceptually equivalent images. These results suggest that although the glossiness and roughness of real objects and their CRIs are perceived differently, reproducing perceptually equivalent glossiness and roughness may be facilitated by measuring the physical features of real objects and reflecting them in image features.