Apple Inc.
NOISE REDUCTION CIRCUIT FOR DUAL-MODE IMAGE FUSION ARCHITECTURE

Abstract:

Embodiments relate to an image processing circuit comprising a noise reduction circuit configurable to perform bilateral filtering on demosaiced and resampled image data, or on raw image data, based on the operating mode of the image processing circuit. The noise reduction circuit filters received image data based upon directional taps, by selecting, for each pixel, a set of neighbor pixels, and comparing values of the set of neighbor pixels to determine whether the pixel lies on a directional edge. For raw images, the noise reduction circuit selects the set of neighbor pixels to include a plurality of pixels of the same color channel as the pixel, and one or more additional pixels of a different color channel, where color values for the one or more additional pixels are determined by interpolating color values of two or more adjacent pixels of the same color channel as the pixel.