IMAGE DISCRIMINATING METHOD, IMAGE PROCESSING METHOD USING IT, AND STORAGE MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide an image discriminating method automatically discriminating whether a document is a photographic image or a drawn image. SOLUTION: The output values of the R, G, B colors outputted from picture elements forming the image are detected (S201). Luminance values Y are calculated from the detected output values (S202), and histograms of the output values and the luminance values are generated (S203). The correlation coefficients of the histograms of the color output values against the histograms of the luminance values are calculated (S204), and whether the correlation coefficients are larger than a specific value or not is judged (S205). If there are two correlation coefficients larger than the specific value as a result of the judgment (S206), the read image is discriminated as the photographic image (S207). If there is one or no correlation coefficient larger than the specific value, the read image is discriminated as the drawn image (S208). A color reducing process is applied to the image discriminated as the drawn image.