Gradation common data generating apparatus and gradation common data recovering apparatus.

摘要

A shared multilevel data encoding apparatus generates shared multilevel data from outline information showing the outline of a code that can be a character or figure. The shared generated multilevel data expresses the code using a predetermined number of pixels that each have a level. The shared multilevel data encoding apparatus includes an outline information expansion/reduction unit 102 and a multilevel base value calculation unit 103 for generating multilevel data for two levels and multilevel data for three levels, and a shared multilevel data generation unit 105 for generating shared multilevel data for four levels from the generated multilevel data for two levels and multilevel data for three levels. A shared multilevel data decoding apparatus decodes the shared multilevel data to produce multilevel data. The shared multilevel data decoding apparatus includes a multilevel selection unit 108 for selecting two or three levels, a first multilevel data decoding unit 109 for decoding multilevel data for two levels from the shared multilevel data, and a second multilevel data decoding unit 110 for decoding multilevel data for three levels from the shared multilevel data. Decoding is performed by only one of the first multilevel data decoding unit 109 and the second multilevel data decoding unit 110, in accordance with the selection.