Patent Number: 7,102,791

Title: Mask producing method, image outputting device and computer readable recording medium

Abstract: A mask is produced for converting multi-level image data into a halftone image through comparison with a threshold for each pixel. For this purpose, a dot pattern is determined on each of predetermined gray scale levels, and, the mask is created by the dot patterns obtained at the step, where the respective dot patterns are determined independently for every gray scale level.

Inventors: Hirano; Masanori (Kanagawa, JP), Ohuchi; Satoshi (Tokyo, JP)

Assignee: Ricoh Company, Ltd.

International Classification: H04N 1/405 (20060101); H04N 1/407 (20060101); H04N 1/52 (20060101); H04N 1/58 (20060101)

Expiration Date: 9/05/02018