In a method and apparatus for difference measurement of an image, the image is detected by an image sensor array having (N×N) sensor elements, wherein N=2n, n≧2, and n being an integer number, each detected sample value is read as a positive or as a negative sample value according to a sign control pattern from a pattern control unit, and measurement values are generated for measurement template blocks of the image sensor array by a computing unit which computes for each measurement template block a weighted sum of the read sample values of the respective measurement template sensor elements depending on a predetermined measurement template. A measurement template block is, provided for at least four adjacent sensor elements of the image sensor array. The method/apparatus can be used in any kind of digital camera and allows for a fast generation of image data with a hardware implementation of low complexity.