PURPOSE: To apply compression processing to picture data with a prescribed time by calculating a proper quantization table to obtain a desired compression rate based on a compression conversion table generated through actual measurement.
CONSTITUTION: Plural graphics and plural pattern picture data are subjected to compression processing in advance based on plural prescribed quantization Q tables and each of compression data quantity is measured to obtain a compression rate change characteristic. Then a graph for a compression rate and a Q factor value required to obtain desired data quantity is generated and the graph is used for the conversion table. The proper Q factor value required for compressing the data into a desired data quantity is calculated depending on each pattern through the use of the table and the Q table is decided for the compression processing. Thus, the picture data are compressed into almost a constant data quantity. Thus, in the case of transmission, the data transmission for one pattern is finished for a prescribed time.
MASUKO SHINJI
YOSHIDA SHINYA
| JPH04362876A | 1992-12-15 |