Picture signal processing method

Abstract

Abstract PURPOSE:To discriminate exactly a character image and a halftone image from a picture information source in which both of them have been mixed, by providing a space filter respect to a notice picture element and its peripheral picture element, comparing its output with a prescribed threshold level, and using it as a discriminating signal. CONSTITUTION:An analog signal from an image sensor 21 is applied to a series circuit of line memories 25, 27 and a series circuit of shift registers 261, 262 through an A/D converting circuit 22. Outputs of the line memories 25, 27 are provided to series circuits of shift registers 263, 264 and the same 265, 266, respectively. An output of the A/D converting circuit 22, outputs of the line memories 25, 27, and each output of shift registers 261-266 are supplied to a filter operating circuit 28, and with respect to nine kinds of picture signals which have been inputted in this part, a filter coefficient is multiplied, and their total is calculated. This result is compared with a prescribed threshold level by a comparator 31, and a compared output is supplied to a multiplexer 32. In this way, an output of a multivalue dither circuit 34 or a simple multivalue circuit 35 is selected and fetched.

Inventors

• 👤 Masami Kurata
• 👤 倉田　正實
• 👤 Taiji Nagaoka
• 👤 永岡　大治
• 👤 Hiroyuki Saito
• 👤 宏之 斎藤

Bibliographic Details