Subtractive color processing system for digital imaging

A solid-state, digital color image capture and processing system for capturing a color image, generating a compressed set of digital values representative thereof, and reconstructing the image from the compressed set of digital values, the system comprising:

• a multiple-pixel focal plane array (FPA) for sampling the image, said FPA having a set of pixels, each pixel being disposed along an image plane to sample a respective portion of the image, said FPA also having a color filter array disposed on said image plane, said color filter array having subtractive color filter elements of different predetermined colors, arranged such that at each pixel of the FPA, the FPA samples a digital value corresponding to a respective one of the different predetermined colors, whereby the set of digital values sampled by the complete set of pixels of the FPA is a compressed digital dataset representative of the color image, said compressed digital dataset containing fewer values than necessary to constitute complete color planes for each of the different predetermined colors, the subtractive color filter elements being selected from the group consisting of any of (i) cyan, yellow and white, (ii) cyan, magenta and white, or (iii) yellow, magenta and white,
• a memory element in electrical communication with the FPA to store the digital values sampled by the FPA, the set of sampled digital values stored in the memory element being representative of the color image,
• a digital image signal processing circuit adapted to receive the values stored in the memory element, and to generate, from sampled digital values stored in the memory element, a decompressed set of values constituting a reconstructed digital representation of the sampled image, the digital signal processing circuit comprising:
• a digital interpolating circuit which generates, from the sampled values stored in the memory element, a set of cyan, yellow and white values constituting complete cyan, yellow, and white color planes corresponding to the sampled image, the digital interpolating circuit comprising:
• a circuit output at which the digital interpolating circuit rapidly generates, from the sampled white values stored in the memory element, a full resolution black and white image by interpolating only the sampled white values stored in the memory element.

A decoding circuit for generating a reconstructed color image from a compressed digital dataset representative of the color image, the compressed digital dataset being generated by a focal plane array (FPA) having a subtractive color filter array thereon, said color filter array having subtractive color filter elements of cyan, yellow and white, arranged such that at each pixel of the FPA, the FPA samples a digital cyan value, a digital yellow value, or a digital white value, whereby the set of digital cyan, yellow and white values sampled by the full set of pixels of the FPA is a compressed digital dataset representative of the color image, said compressed digital dataset containing fewer values than necessary to constitute complete cyan, yellow and white color planes representative of the sampled image, the decoding circuit comprising:

• a digital image signal processor adapted to receive the values generated by the FPA and to generate, from sampled digital values stored in a memory element, a set of values constituting a reconstructed digital representation of the sampled image, the digital image signal processor including:
• a digital interpolating circuit which generates, from the sampled values stored in the memory element, values constituting a complete set of cyan, yellow and white color planes corresponding to the sampled image, and
• a circuit output at which the digital image signal processor rapidly generates, from the sampled white values stored in the memory element, a half-resolution black and white image by selecting and transmitting only the sampled white values stored in the memory element.

A decoding circuit for generating a reconstructed color image from a compressed digital dataset representative of the color image, the compressed digital dataset being generated by a focal plane array (FPA) having a subtractive color filter array thereon, said color filter array having subtractive color filter elements of cyan, yellow and white, arranged such that at each pixel of the FPA, the FPA samples a digital cyan value, a digital yellow value, or a digital white value, whereby the set of digital cyan, yellow and white values sampled by the full set of pixels of the FPA is a compressed digital dataset representative of the color image, said compressed digital dataset containing fewer values than necessary to constitute complete cyan, yellow and white color planes representative of the sampled image, the decoding circuit comprising:

• a digital image signal processor adapted to receive the values generated by the FPA and to generate, from sampled digital values stored in a memory element, a set of values constituting a reconstructed digital representation of the sampled image, the digital image signal processor including:
• a digital interpolating circuit which generates, from the sampled values stored in the memory element, values constituting a complete set of cyan, yellow and white color planes corresponding to the sampled image, the digital interpolating circuit comprising:
• a circuit output at which the interpolating circuit rapidly generates, from the sampled white values stored in the memory element, a full resolution black and white image by interpolating only the sampled white values stored in the memory element.

A method of capturing a color image, generating a compressed set of digital values representative thereof, and reconstructing the image from the compressed set of digital values, the method comprising the steps of:

• providing a multiple-pixel focal plane array (FPA) for sampling the image, said FPA having a set of pixels, each pixel being disposed along an image plane to sample a respective portion of the image,
• disposing a subtractive color filter array on an image plane of the FPA, said color filter array having subtractive color filter elements of different predetermined colors, the arrangement of subtractive color filter elements forming a subtractive filter mosaic in which subtractive color filter elements each overlie a respective pixel of the FPA,
• configuring the subtractive color filter array to have subtractive color filter elements of cyan, yellow and white,
• sampling the image with the multiple-pixel FPA upon which the subtractive color filter array is disposed, such that each pixel of the FPA samples a digital value corresponding to a respective one of the different predetermined colors, whereby the set of digital values sampled by the complete set of pixels of the FPA is a compressed digital dataset representative of the color image, said compressed digital dataset containing fewer values than necessary to constitute complete color planes for each of the different predetermined colors,
• storing the digital values sampled by the FPA in a memory element, the set of sampled digital values stored in the memory element being representative of the color image, and
• generating, from the sampled digital values stored in the memory element, a decompressed set of values constituting a reconstructed digital representation of the sampled image,
• said generating step including the step of utilizing a digital signal processing circuit,
• the step of configuring the subtractive color filter array to have subtractive color filter elements of cyan, yellow and white including the step of configuring the subtractive color filter array to have a mosaic pattern consisting of 50% white pixels, 25% cyan pixels, and 25% yellow pixels,
• the step of generating a decompressed set of values constituting a reconstructed digital representation of the sampled image comprising the step of interpolating across the set of sampled cyan, yellow and white values stored in the memory element to generate a set of cyan, yellow and white values constituting complete cyan, yellow, and white color planes corresponding to the sampled image,
• the step of interpolating comprising:
• generating, from the sampled white values stored in the memory element, a full resolution black and white image, by interpolating only the sampled white values stored in the memory element.

A method of generating a reconstructed color image from a compressed digital dataset representative of the color image, the compressed digital dataset being generated by a focal plane array (FPA) having a subtractive color filter array thereon, said color filter array having subtractive color filter elements of cyan, yellow and white, arranged such that at each pixel of the FPA, the FPA samples a digital cyan value, a digital yellow value, or a digital white value, whereby the set of digital cyan, yellow and white values sampled by the full set of pixels of the FPA is a compressed digital dataset representative of the color image, said compressed digital dataset containing fewer values than necessary to constitute complete cyan, yellow and white color planes representative of the sampled image, the method comprising the steps of:

• generating, from digital values sampled by the FPA, a set of values constituting a reconstructed digital representation of the sampled image, the step of generating a set of values constituting a reconstructed digital representation of the sampled image including the step of
• interpolating across the digital cyan, yellow and white values sampled by the FPA to generate respective cyan, yellow and white values constituting complete cyan, yellow and white color planes corresponding to the sampled image,
• the step of generating a set of values constituting a reconstructed digital representation of the sampled image, and
• generating, from the sampled white values stored in the memory element, a half-resolution black and white image by selecting and transmitting only the sampled white values stored in the memory element.

A method of generating a reconstructed color image from a compressed digital dataset representative of the color image, the compressed digital dataset being generated by a focal plane array (FPA) having a subtractive color filter array thereon, said color filter array having subtractive color filter elements of cyan, yellow and white, arranged such that at each pixel of the FPA, the FPA samples a digital cyan value, a digital yellow value, or a digital white value, whereby the set of digital cyan, yellow and white values sampled by the full set of pixels of the FPA is a compressed digital dataset representative of the color image, said compressed digital dataset containing fewer values than necessary to constitute complete cyan, yellow and white color planes representative of the sampled image, the method comprising the steps of:

• generating, from digital values sampled by the FPA, a set of values constituting a reconstructed digital representation of the sampled image, the step of generating a set of values constituting a reconstructed digital representation of the sampled image including the step of
• interpolating across the digital cyan, yellow and white values sampled by the FPA to generate respective cyan, yellow and white values constituting complete cyan, yellow and white color planes corresponding to the sampled image,
• the interpolating step includes the further step of
• generating, from the sampled white values stored in the memory element, a full resolution black and white image, by interpolating only the sampled white values stored in the memory element.