Apparent Color Dataset: How Apparent Color Differs from the Color Extracted from Photos

Apparent color and pixel color are known to be different due to color constancy and contexts of images. An apparent color dataset for photographs and images will be a basis for developing perception-based color extraction and transfer system. In this study, we collected the apparent color dataset for a given image and extracted position through an online experiment that mimics the situation of using a color extraction system. Additionally, we analyzed 1110 data and verified the difference between apparent color and pixel color. As a result, approximately 80% data has $\Delta E_{\mathrm{NBS}} \gt 6.0$ color difference that is defined “Much” or “Very Much” difference by the national bureau of standards (NBS). Luminance (L*) of the apparent color was on average $\triangle E_{00}=[9.90,11.9]$ (95% confidence interval) greater than that of the pixel color. These results indicate that the color deviations cannot be ignored when apparent colors are extracted in images.