An interpolation method for producing full color images is disclosed. For a blue pixel, an interpolated green value is determined by green values of adjacent green pixels, and an interpolated red value is determined by red values of neighboring red pixels and a modification value. For a red pixel, an interpolated green value is determined by green values of adjacent green pixels, and an interpolated blue value is determined by blue values of neighboring blue pixels and a modification value. For a green pixel, an interpolated green value is determined by original green value of the green pixel and green values of neighboring green pixels, an interpolated red value is determined by red value of at least an adjacent red pixel and a modification value, and an interpolated blue value is determined by blue value of at least an adjacent blue pixel and a modification value.
An imaging apparatus including: a single-chip image sensor with a color filter array and capable of intermittent readout operation in horizontal and vertical directions; an intermittence control means for controlling the intermittent readout operation of the image sensor; and an interpolation means for processing signals read out from the image sensor in a thinned out pattern designated by the intermittence control means to form a reduced image consisting of trichromatic components; wherein the intermittence control means reads signals at a plurality of locations on the image sensor correspondingly to each pixel of the reduced image and controls reading at that time so that there are two or more types of color filters at the readout locations and at least one type of the color filters thereof is common to all pixels of the reduced image and at least one type of the color filters is not common to all pixels of the reduced image; and the interpolation means supplements signals corresponding to the type of unread color filter at each pixel of the reduced image to compute trichromatic components of an observed pixel.
A gradient-corrected linear interpolation method and system for the demosaicing of color images. The method and system compute an interpolation using some a current technique (preferably a bilinear interpolation technique to reduce computational complexity), compute a correction term (such as a gradient of a desired color at a given pixel), and linearly combine the interpolation and the correction term to produce a corrected, high-quality interpolation of a missing color value at a pixel. The correction term may be a gradient correction term computed from the current color of the current pixel. This gradient is directly used to affect and correct the estimated color value produced by the prior art interpolation technique. The gradient-corrected linear interpolation method and system may also apply a gradient-correction gain to the gradient correction term. This gradient-correction gain affects the amount of gradient correction that is applied to the interpolation.
A new color space that maps image pixel values in a mosaiced sampling pattern (such as that generated by a Bayer color filter array) into four color channels that correspond to rectangular sampling patterns. Because these new channels correspond to a rectangular sampling grid, they are much more amenable to processing steps such as compression. In one embodiment, the transformation from the original mosaic-patterned pixels into the new four-channel color space can be made reversible in integer arithmetic. That allows for the implementation of efficient lossless image compression systems for mosaiced (e.g., raw, or raw Charged Couple Device (CCD)) images.
