Image processing apparatus

#1. Field of the Invention

#The present invention relates to an image processing apparatus for obtaining a high-quality image by processing image data captured by a CCD (charge-coupled device) area sensor using a complementary-color filter. The image processing apparatus may be used in a digital camera (e.g., an electronic still camera) or the like.

#2. Description of the Related Art

#FIG. 1 is a block diagram showing a configuration of an image processing apparatus according to an example of the present invention.

#FIG. 2 is a plan view showing a color array of a complementary-color filter.

#FIG. 3 is a plan view showing a part of the color array of the complementary-color filter of FIG. 2.

#Hereinafter, the present invention will be described by way of illustrative examples with reference to the accompanying drawings.

#FIG. 1 is a block diagram showing a configuration of an image processing apparatus according to an example of the present invention. Referring to FIG. 1, an image processing apparatus 1 includes: an optical low-pass filter 2; a complementary color CCD area sensor 3; a low-frequency luminance signal generating Ye, Cy, Gr, Mg interpolation section 4 (hereinafter referred to as a low-frequency luminance signal generating interpolation section 4) for interpolating components; an RGB generation section 5; a white-balance adjustment gamma correction section 6; a low-frequency luminance signal generation section 7 (hereinafter also referred to as a constant luminance signal generation section); a color difference signal generation section 8 for generating color difference signals Cr and Cb: and an adaptive median filtering section 9.

#The optical low-pass filter 2 cuts out high-range luminance components higher than or equal to ½ of an actual sampling frequency fs. The sampling frequency fs is equal to 1/Δx=1/Δy where Δx and Δy are a pixel pitch as shown in FIG. 2.