Apparatus and method for memory saving wavelet based video coding

Abstract

A method and apparatus for compressing video signals. The video compression may include row by row horizontal subband filtering of video data representing part of an image, and row by row concurrent vertical high and vertical low pass subband filtering of the results of the horizontal subband filtering. Less than the vertical filter length of rows of results of the horizontal subband filtering may be buffered at a time. The vertical high and vertical low pass subband filtering may include calculating a first result row by adding a first row of a recursion buffer to the results of multiplying a row of results from the horizontal subband filtering and a first vertical filter coefficient, calculating a second result row by adding the first row of the recursion buffer to the result of multiplying the row of results of the horizontal subband filtering and a second vertical filter coefficient, overwriting the first row of the recursion buffer with the second result row, and transmitting the first result row to be encoded.