Patent ID: 6977961
Filing Date: 2005-12-20
Classification: H04N

Abstract:
1. Apparatus for coding video data, comprising means for receiving pixel values organised in frames each comprising a matrix of video blocks, each video block comprising a video matrix of N pixel values, and processor circuitry arranged: a) to set each element in a prediction matrix to an initial prediction value; b) in the prediction matrix, to apply a smoothing transform to the values along rows and then along columns, or vice versa, to obtain interpolated values; c) to set the prediction values to the interpolated values; d) to calculate the differences between the prediction values and corresponding received pixel values to produce a residual prediction matrix containing prediction residuals; and e) to perform a discrete cosine transform on the prediction residuals to obtain elements of a compressed video data matrix, wherein the processor circuitry is arranged iteratively to calculate the prediction values used to calculate the prediction residuals by repeating b) and c); and wherein a) is performed by performing a discrete cosine transform on the video matrix to obtain a transform video matrix of N coefficients, selecting n of the coefficients, setting the N-n remaining coefficients to zero to obtain an initial prediction transform matrix of initial prediction coefficients, and performing an inverse discrete cosine transform on the initial prediction transform matrix to obtain a matrix of N initial prediction values.