Solid-state image sensor having pixels shifted and complementary-color filter and signal processing method therefor

Abstract

A solid-state image sensor capable of enhancing efficient use of incident light and increasing the resolution of an image and a signal processing method therefore are disclosed. A digital camera includes an image pickup section having a photosensitive array in which photosensitive cells or photodiodes are arranged. Signal charges, or pixel data, are read out of the photodiodes, two lines at a time, three lines at a time, or three lines at a time with line-by-line shift in accordance with a color filter using complementary colors. A signal processing section includes a data correcting circuit for correcting the pixel data. Pixel data of one of three primary colors R, G and B is interpolated in the position of each virtual photosensitive cell or that of each real photosensitive cell. The above color filer uses more efficiently incident light than a filter using the primary colors and improves the sensitivity of the photosensitive cells in a dense pixel arrangement, thereby contributing to the enhancement of image quality. Further, the generated pixel data are used to interpolate pixel data in the real photosensitive cells or the virtual photosensitive cells. This is successful to broaden the frequency band of the pixel data of the real photosensitive cells or those of the virtual photosensitive cells and therefore to improve image quality while obviating false colors.