System for compression and decompression of video data using discrete cosine transform and coding techniques

摘要

A method and a structure provide discrete cosine transform (DCT) and its inverse (IDCT) using digital FIR filters in a filter bank. The filter bank of the present invention forms a structure of cascaded filters, in which data are communicated only between filters having "parent-child" relationships. Each filter in the filter bank is required only to communicate with at most two other filters in the filter bank. Consequently, in any implementation, both the communication overhead between filters in the filter bank, and the circuit size are minimized. Therefore, the filter bank is particularly suited for integrated circuit implementation. In one embodiment, the filter bank is implemented in an image compression and decompression integrated circuit using a structure which includes pipeline registers, adders and multipliers. In that embodiment, the filter bank provides an 8-point DCT in each of the two passes of a 2-dimensional DCT used in a data compression operation. The same structure also provides an 8-point IDCT in each of the two passes of the 2-dimensional IDCT used in an data decompression operation.