| 摘要 |
PURPOSE: To reduce data amount than that before data are compressed by performing compression by a prescribed logical system after data are provided with redundancy. CONSTITUTION: The character data of a color pallet form are compressed and address-translated data are synthesized. When the synthesized data are less than before data are compressed, the synthesized data are compressed as they are. On the other hand, when the data are larger than before data are compressed, the character data of the color pallet form are decomposed into the data of an RGB or YIG color space system by a first data system transforming part 22, afterwards, spatial correlation is removed by performing discrete cosine transform at an axial transforming part 23, energy is concentrated to one part of coefficient and further, data are quantized by a quantizing part 24. Then, when the data are returned to the color pallet form again by an inverse quantiation part 25, inverse axial transforming part 26 and second data system transforming part 27, the data are provided with redundancy. Then, these data provided with redundancy are compressed by the prescribed logical system. |
