Device for correcting shading distortion

Abstract

Abstract PURPOSE:To execute shading correction, which is easy to be realized as a comparatively inexpensive integrated circuit and has high accuracy and stability by adopting an MOS type A/D convertor using a small chopper comparator of offset voltage as circuit constitution. CONSTITUTION:Prior to reading an original, reading and scanning of a white reference plate 5 is executed by a scanner 2 and a white reference scan signal is inputted in an A/D convertor 9, a correction coefficient M is read out from an ROM10 address which is designated by the white reference scan signal changed into a digital, and wrote in an address which is in correspondence to a picture element of an RAM11. Then an original 4 is transferred to a read position, and an original scan signal is inputted in a device 1 for correcting shading strain from the scanner 2. At this time, the RAM11 is operated in a read mode and outputs a correction coefficient by synchronizing with a read scan. An operator 12 performs multiplication of said correction coefficient and the original scan signal which is changed into digitals by the A/D convertor 9 and outputs the original picture information whose shading strain is corrected.

Inventors

• 👤 Mitsuo Togashi
• 👤 富樫　光夫
• 👤 Shinichi Sato
• 👤 真一 佐藤
• 👤 Toshiaki Watanabe
• 👤 俊明 渡辺
• 👤 Shiyoutoku Ooshima
• 👤 大島　昇徳
• 👤 Tatsu Nakamura
• 👤 達 中村
• 👤 Kazuyoshi Ariga
• 👤 有賀　和義

Bibliographic Details