Peproducing device for halftone picture

Abstract

Abstract PURPOSE:To improve the correlation between tone and average luminance, by taking the threshold level of a middle cell of a dither matrix to a low level and sequentially increasing the threshold level of surrounding cells. CONSTITUTION:The X address of a picture memory 103 is advanced one by one with every one clock of a clock generator 1 and the column address of a matrix memory 105 is advanced one by one. On the other hand, a main scanning sychronizing signal HS of a laser beam electrophotography recorder 106 advance the Y address of the memory 103 one by one and advances the row address of the memory 105 with the row counter 108 one by one. Thus, the video information of the memory 103 is compared with the threshold of the memory 105, and a recording signal is outputted to a device 106 sequentially. In this case, the threshold levels of the middle cell of the memory 105 is taken as the lowest level to make recording with improved correlativity between the tone and the average luminance.

Inventors

• 👤 Shinichi Oota
• 👤 Keiichi Kawasaki

Bibliographic Details