IMAGE PROCESSING METHOD AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of forming a high- grade image by enhancing the printing stability of a highlight part without generating the bad effect due to excessively applied energy in a shadow part. SOLUTION: In an image forming apparatus dividing inputted image gradation value data into a plurality of blocks to convert the same to multi-value data for performing recording according to the gradation converting characteristic determined corresponding to the relative pixel positions in the blocks to perform gradation recording, the gradation converting characteristic is set to B<A when the max. value of the multi-value data to the medium contrast or less of the printing density of the image gradation value data is set to A and the min. value of an envelope curve obtained by connecting the max. values of multi-value data to respective converting characteristic curves wherein printing density is a medium contrast or less is set to B.