Simple Differential Predictive Coding
A more common coding scheme for natural images is simple differential coding. In this case the predicted pixel value is simply the value of the preceding pixel. The signal representing the difference between the predicted pixel and the actual pixel, called the prediction error, is transmitted by an entropy code.
Many more complex predictors can be proposed, from ones using only previously scanned pixels, all the way to schemes using pixels from both previous and following video frames. MPEG uses a particularly powerful prediction scheme involving motion-compensated prediction from previous and/or subsequent frames.
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