1. Field of the Invention
The present invention relates to a technology for processing an image captured by an optical system having a wide angle and a large chromatic aberration of magnification.
2. Description of the Related Art
Recently, demands for a wide-angle small imaging apparatus have been increasing for an application such as a back monitor of a vehicle. However, it is difficult to design a small optical system with a small aberration and distortion, and performance needs to be improved in combination with image processing. For example, in Japanese Patent Application Laid-open No. 2006-345054 is described a method of correcting a magnification chromatic aberration generated in an optical system, in an imaging apparatus using an optical system having a distortion, by performing coordinate transformation for each of R (red), G (green), and B (blue) signals obtained by an imaging device such as a charge coupled device (CCD) and a complimentary metal oxide semiconductor (CMOS) to generate different distortion.
Generally, a color filter such as of a Bayer array is provided in the imaging device. In the conventional art, after a defective pixel due to the color filter array such as the Bayer array is interpolated, the magnification chromatic aberration is corrected with respect to a signal obtained by the imaging device.
However, to correspond to an optical system having a large magnification chromatic aberration, a quite large memory capacity is required for the magnification chromatic aberration (for coordinate transformation), and the device becomes very expensive. Further, because the magnification chromatic aberration is different for each color component, a memory capable of addressing independently for each color component is required for correction of the magnification chromatic aberration, and it is necessary to use an expensive 3-port random access memory (RAM) (for example, a static RAM (SRAM)) having a 3-chip configuration or to drive a RAM in a time-sharing manner, which makes the device even more expensive.