| 摘要 |
PROBLEM TO BE SOLVED: To efficiently and quickly compress or decompress an image or image data in order to store and access them by encoding respective quantized coefficients in a coefficient group in accordance with an entropy code. SOLUTION: Image groups are extracted from a two-dimensional(2D) monochromatic image 401 and each image group is processed in relation to a selected image group 402. The image group 402 is processed by eight-point fast Hartley(FHT) transformation means 403. Namely, FHT transformation for rows and FHT transformation for columns are calculated. An optional accuracy controller unit controls the accuracy of the FHT. A quantization means 404 quantizes the coefficient which is the output of the means 403. The quantized coefficient is outputted to an entropy coder 405, which encodes each coefficient and generates a data-encoded bit stream to be stored in a digital memory. |
