摘要 |
An image signal (V1) is transform coded in a Discrete cosine Transform Coder (DCT) and the output coefficients thus provided are encoded in a zonal encoder (QZ). The output of QZ is inversely coded (IQZ) and substracted from the coefficients of the DCT. The resulting error is encoded in an entropy encoder. Both the zonal coder and the entropy encoder have quality inputs (TZQ, TEQ) controlling the compression factor, and have their outputs combined in a single compressed data stream (TXD3). |