Patent ID: 7825965

Claim:
A method of interpolating missing colors in a color filter array (CFA) comprising red, green and blue photosites, the method comprising: using an edge detector and one or more interpolators to: determine an interpolation direction for each red and each blue photosite based on local edge information; interpolate a green color for each red and each blue photosite in the determined interpolation direction for the each red and each blue photosite; for each green photosite, interpolate red and blue colors; for each red photosite, interpolate a blue color in the determined interpolation direction for the each red photosite; and for each blue photosite, interpolate a red color in the determined interpolation direction for the each blue photosite; and then reduce Moiré by converting each photosite from RGB color space to YCbCr to produce converted photosites; selecting each converted photosite, and for each selected converted photosite modifying a Cb value of the each selected converted photosite to a Cb average of converted photosites within a window that is centered at the each selected converted photosite; and wherein said green color interpolating in vertical and horizontal directions for each red photosite involves local green and red photosites; and for an upper vertical directional gradient, local green and red photosites in a first region that extends to the sides of and above the selected red photosite are used, a central strand of photosites of the first region comprises four photosites and extends vertically upwards beginning at the selected red photosite, and adjacent flanking strands of photosites comprise three photosites; for a lower vertical directional gradient, local green and red photosites in a second region that extends to the sides of and below the selected red photosite are used, a central strand of photosites of the second region comprises four photosites and extends vertically downwards beginning at the selected red photosite, and adjacent flanking strands of photosites comprise three photosites; for a left horizontal directional gradient, local green and red photosites in a third region that extends above and below and to the left of the selected red photosite are used, a central strand of photosites of the third region comprises four photosites and extends horizontally to the left beginning at the selected red photosite, and adjacent flanking strands of photosites comprise three photosites; and for a right horizontal directional gradient, local green and red photosites in a fourth region that extends above and below and to the right of the selected red photosite are used, a central strand of photosites of the fourth region comprises four photosites and extends horizontally to the right beginning at the selected red photosite, and adjacent flanking strands of photosites comprise three photosites.