In a method of compressing image data which include a plurality of pixel values which are associated with a respective pixel, the pixel values are coded for at least some pixels in accordance with the following steps: determining an estimated pixel value of the respective pixel in dependence on the pixel value of at least one predetermined other pixel while using an estimation rule; and forming a difference value of the respective pixel which corresponds to a predefined relation between the pixel value and the estimated pixel value of the respective pixel and quantization of the difference value in accordance with a difference value quantization rule. The quantized difference values of the pixels are compressed in accordance with a compression rule.