Image warmness - a new perceptual feature for images and videos

Many basic, but very useful features, for characterizing an image or calculating the similarity between two images are based on color information. Psychological studies show that beyond the tone of color, different colors are also associated with different emotions. Thus, two colors that trigger the same impression are most likely considered to be more similar than two colors which trigger the opposite impression. We introduce a new feature called image warmness. It is based on the cold or warm impression that a single color triggers in the brain of the beholder. Image warmness provides a measure about how cold or warm an entire image is perceived by humans based on colors it contains. In a survey and evaluation with 90 images and 101 participants we show that the values of image warmness calculated by the proposed formula are close to the average rating of the survey participants.