Picture signal processing method

Abstract

Abstract PURPOSE:To correct the two-dimensional shading of a picture at high accuracy by provisionally reading only a two-dimensional luminous energy distribution including only a light source without picture information to obtain reference data and correcting the main- and subscan directions of video data. CONSTITUTION:One-dimensional image sensor 104 scans a microfilm projection image 300 electrically in the main scan direction X and mechanically in the subscan direction. For each picture element unit from the sensor 104, sequentially video data is transmitted to a shading correction circuit 320 through an amplifier 310. After the corrected video data is binarized by a binarization circuit 340, other required processing is done through an interface circuit. First, reference data for two-dimensional shading is obtained, and then the gain of a D/A converter is adjusted by a correction coefficient corresponding to the reciprocal number of the reference data to correct the shading in the subscan direction. Moreover a picture signal is D/A-converted while an D/A converter executes the shading correction in the main scan direction with the aid of a reference signal.

Inventors

• 👤 Ryoichi Watanabe
• 👤 良一 渡辺

Bibliographic Details