Patent ID: 6341144
Filing Date: 2002-01-22
Classification: H04N

Abstract:
A method of decoding coded signals of a block of new image data, comprising the steps of:identifying a first block of image data vertically adjacent to the block of new image data, a second block of image data horizontally adjacent to the first block and a third block of image data horizontally adjacent to the block of new image data, and vertically adjacent to the second block; determining a horizontal gradient between the first block and the second block; determining a vertical gradient between the third block and the second block; predicting image data for the block of new image data based on the horizontal and vertical gradients, wherein the predicting step further comprises the steps of: in the event that the vertical gradient is less than the horizontal gradient, predicting the image data for the block of new image data based on the image data of the first block, and in the event that the horizontal gradient is less then the vertical gradient, predicting the image data for the block of new image data based on the image data of the third block; identifying a residual image signal from a coded signal; generating an image signal for the block of new image data from the predicted image data and the residual image signal; and scanning the coded signals, preliminary to the prediction step, wherein in the event that the vertical gradient is less than the horizontal gradient, the scanning proceeds in a horizontal-diagonal direction, and in the event that the horizontal gradient is less than the vertical gradient, the scanning proceeds in a vertical-diagonal direction.