Display and record method of false halftone of picture

Abstract

Abstract PURPOSE:To secure the satisfactory number of gradations and image resolution to an optional picture by dividing each rectangular block into plural minor blocks and binary-coding them according to the difference between the maximum and minimum luminance levels within each rectangular block. CONSTITUTION:Both the maximum and minimum luminance levels are obtained and the difference of both levels is calculated within each rectangular block when a screen is divided into plural rectangular blocks (8X8 picture elements). When said level difference is smaller than the threshold value D1 set previously, a dither matrix of (8X8) picture elements is used for false gradation. In case the level difference is larger than the value D1 and smaller than the threshold value D2, the rectangular blocks of (8X8) picture elements are divided into minor blocks of (4X4) picture elements and then binary-coded by means of a dither matrix B. When the level difference is larger than the value D2, the blocks are divided into 16 minor blocks of (2X2) picture elements.

Inventors

• 👤 Yoshifumi Imanaka
• 👤 今中　良史

Bibliographic Details