Motion detection using sub-band image processing. A device has decompose logic that decomposes an input image into composite images that comprise different frequency bands of the input image. The device also has storage coupled to the decompose logic to store composite images as reference images for comparison with a later input image. The device further has comparison logic to compare the composite images with the reference images to produce preliminary motion values for the different frequency bands. The device also has logic to determine a final motion value from the preliminary motion values.