| 摘要 |
PROBLEM TO BE SOLVED: To decide the arrangement of pixels after resolution conversion on the basis of a conversion result for the pixel under consideration and a result after error propagation and to output the images of high image quality without increasing a work memory. SOLUTION: Multi-valued images read in an image input means are inputted to an image conversion means 31 and an error propagation means 32 and image conversion and gradation conversion to the multi-valued images are performed. The output result of the error propagation means 32 and the output result of the image conversion means 31 are inputted to a double density image preparation means 33 and the image having the double resolution for the pixel under consideration after the error propagation is prepared. Since the information of the state before an image quality processing of the pixel under consideration is preserved by the image conversion means 31 and double density conversion is performed by utilizing it, the output images of the high image quality are obtained by simple constitution. |
