Abstract: A method for prediction weights determination for use in compression (particularly image compression) and forecasting applications. Prediction weights determining significance of different predictions when calculating generalized prediction are calculated using specific context-based procedure. Information about already known best predictions in close neighborhood of the position being processed is used to form prediction context. Number of times each particular prediction was the best prediction in past in current prediction context is treated as a prediction weight.

Abstract: A method to efficiently detect, and thus store, approximately duplicate or most likely duplicate files or data sets that will benefit from differencing technology rather than standard compression technology. During archive creation or modification, sets of most likely files are detected and a reduced number of transformed file segments are stored in whole. During archive expansion, one or more files are recreated from each full or partial copy.