| 摘要 |
A method for compressing image data having pixels arranged like a matrix in a line direction and a sub scan direction orthogonal to the line direction is provided. The method includes the steps of dividing the image data in the line direction and in the sub scan direction into blocks covering a plurality of lines, determining a representative value about density of pixels included in each of the blocks, determining additional information for each one line in each of the blocks or for each plurality of lines whose number is smaller than the number of lines of the block in each of the blocks, the additional information being information about the density of each of the pixels to be used instead of the representative value or to be added to the representative value, if there is, and creating compressed data by using the representative value and the additional information.
|
