A scaling device for an image processor includes an image enlarging device and an integer divider. The image enlarging device receives an input image data, and enlarges the input image data, outputting an enlarging image data and a sample signal. The integer divider receives the enlarging image data, and samples the enlarging image data, outputting an object image data. By only adding an external integer divider at the output of the image enlarging device for obtain the scaling function of the image processor, a simpler circuit for image scaling is presented.