A method for generating print data for digital color images uses a division of the images in windows. Each window is characterized as belonging to a predefined class, based on values of pixels in corresponding windows in at least two sub-images that are derived from the color image by a series of image processing steps. These sub-images are, e.g. a gradient sub-image in which the value of every pixel indicates the difference of that pixel with its local neighborhood and a non-uniformity sub-image in which each pixel determined to be comprised in a uniform area is provided with a predetermined value. The percentage of windows belonging to a class is calculated and compared to threshold values to identify an image type. This image type is used to select a conversion method to convert the color image into print data for printing on the printer system.