| 摘要 |
PURPOSE:To always obtain a constant compression ratio at every block by encoding the data of the hierarchy of gradation and the hierarchy of resolution and stopping an encoding processing at a point of time when the total amount of encoded data reaches preliminarily set code amount. CONSTITUTION:In a significant rank determination device 3, the ranking of each hierarchy when the picture element within a block is divided into the hierarchy of resolution and the hierarchy of gradation is performed based on an analysis result 8. In this case, the hierarchy of prescribed resolution and the hierachy of gradation are defined as a first rank, and the candidate of the hierarchy of the resolution and the candidate of the hierarchy of gradation where an input block 7 is available to be decoded in a state less than a prescribed encoded error, are determined respectively on the feature amount of resolution and the feature amount of gradation. By starting from the first rank hierarchy of resolution and the hierarchy of gradation, the ranking is performed for the candidate of the hierarchy of resolution and the candidate of the hierarchy of gradation. At this point, a rank 9 and the output 10 of a gradation/ resolution computerization device 4 are encoded by an information source encoder 5, encoded data amount is added to it, and it is terminated by reaching an aimed code amount. |
