Affective information processing is an advanced research direction in the AI world. Affective Information of image is taken as the objective of research in this paper. The influence of color vision properties’ histograms of image on human emotions is analyzed. Then based on 1/f fluctuation theory, a model of two-dimensional 1/f fluctuation is established, on which analysis is made on the fluctuation characteristics of image, resulting in a new algorithm proposed to objectively evaluate the harmonious feeling of image. After that, psychological testing method of SD is applied to verify the uniformity of the objective and subjective evaluations. At last, a conclusion is drawn that the image with 1/f fluctuation is harmonious and beautiful.