Picture Quality Improvement for a Single CCD Color TV Camera for Line Sequential System with a Green Dot Checkerboard Pattern

Abstract

This paper describes a color TV camera using a single interline-transfer CCD image sensor with Bayer geometry color filter array. Since this color camera obtains red and blue signals by a line sequential system and interpolates them by a zero-order hold circuit, a coloring like missregislation occurs at vertical contours and a lateral striped color distortion, tint changing repeatedly at every scanning line, occurs at scenes which brightness changes gradually in the vertical direction. The causes of these phenomena are explained. The methods compensating for them and these effects are specified. Further, a effect of an optical low-pass filter and a effect of adding an upper frequency component of green signal to input signals of three gamma correcting circuits are also described. These counter plans are very effective to improve the picture quality and this color camera satisfies the performance for home use by far.