| 摘要 |
PURPOSE:To obtain a method and device for compressing and coding image data in which the processing time is reduced. CONSTITUTION:Image data are subjected to reduction and block processing by a block processing section 50, a block activity calculation section 60 calculates activity corresponding to each block of reduced image data respectively and the activity is sequentially added by an addition processing section 62 and a total activity calculation section 64 predicts the total activity corresponding to original image data. A quantization coefficient is set to a normalizing section 54 by a quantization coefficient setting section 66 based on the total activity in a 1st path and a transformation coefficient transformed by a 2-dimension orthogonal transformation section 52 is quantized and a 2-dimension Huffman coding section 56 encodes the result. When coded data exceed a prescribed code quantity, the coding is stopped and the code quantity corresponding to the entire image data based on an address of the image data is calculated by a total code quantity calculation section 76, and a quantization coefficient is calculated based on the entire code quantity in a 2nd path and image data are quantized and coded by the quantization coefficient. |
