1. A method of compressing an image, the method comprising: applying a prediction unit to calculate a prediction value of a pixel to be encoded in a frame of said image, wherein the pixel to be encoded lies on a straight line spatially in between at least two other pixels and the prediction value is at least partially based on the at least two other pixels; determining a difference between the prediction value and an actual value of the pixel to be encoded; encoding the difference with a bounded encoding error; and repeating said calculating, determining and encoding for at least 5% of the pixels of the image.