| 摘要 |
Methods and apparatus are provided for compressing and decompressing electronic image data. The electronic image data comprise two sets of elements which are arranged in an alternating patent. Compression is performed by generating at least two sets of reduced size image data from the electronic image data. Each element of each set of reduced size image data is representative of a plurality of elements of the original electronic image data. A modulation value is assigned to each of the elements of a first of the two sets of elements of the electronic image data and a flag is assigned to respective ones of each of the elements of a second set of the two sets of elements of electronic image data. The flag indicates whether a modulation value for that element is to be derived by interpolating adjacent horizontal elements or adjacent vertical elements. The compressed data is then used in the decompression process. |
