The present disclosure relates to an image signal processing device and method for performing interpolation of pixel signals of three primary colors output from an imaging device including a color filter of a Bayer array.
A pixel signal of each of three primary colors output from an imaging device including a color filter of a Bayer array is only one of pixel signals of R (red), G (green) and B (blue) per pixel.
Pixel signals of two colors other than a pixel which is output as a pixel signal among three pixels are required to be produced by interpolation processing. Processing for producing pixel signals which are not output as pixel signals by interpolation processing is called demosaicing.
An example of the easiest method of demosaicing is a bilinear method for performing linear interpolation using pixel signals of peripheral colors which are the same as a color to be produced by interpolation.
However, the interpolation processing by the bilinear method is not used in general because the method has the disadvantages of, for example, causing false colors at edges of images because of incorrect interpolation and causing great deterioration in resolution.
There is known an adaptive color plane interpolation (ACPI) method commonly used for resolving the disadvantages of the bilinear method. The ACPI method is used for performing interpolation of a pixel signal with reference to pixel signals of colors different from a color to be produced by the interpolation.
U.S. Pat. No. 5,629,734 (Patent Literature 1) discloses interpolation processing by the ACPI method. Japanese Unexamined Patent Application Publication No. 2012-099903 (Patent Literature 2) discloses interpolation processing by a method obtained by improving the ACPI method.