Half-tone image forming device

Abstract

Abstract PURPOSE:To improve the number of gradations and resolution with small threshold matrix size by performing error diffusion processing. CONSTITUTION:This device is equipped with a screen generator 1 which generates a binary coded signal by comparing image data with threshold data, a subtracting circuit 3 which finds the difference between density converted from the constant-value binary coded signal by a density converting circuit 2 and the density of the image data, a correcting circuit 4 which finds a correction quantity for the image data nearby picture elements by multiplying the difference by a correction coefficient, and an adding circuit 5 which corrects the image data with the correction quantity. Then a quantized error is fed back to an input side and the image data corrected by the adding circuit 5 is inputted to the screen generator 1 to generate the binary coded signal. Consequently, the difference is diffused, so even when the binary coding threshold matrix size is reduced so as to increase definition, namely, when the gradations are decreased, the reproducibility of the gradations is increased.

Inventors

• 👤 Yuzuru Suzuki
• 👤 譲 鈴木
• 👤 Masao Nazeki
• 👤 名関　正生
• 👤 Kazumitsu Yanai
• 👤 谷内　和満
• 👤 Koji Inoue
• 👤 幸治 井上
• 👤 Hiroshi Sekine
• 👤 弘 関根

Bibliographic Details