Color filter arrangements for fused array imaging systems
View Patent ↗Electronic devices may include camera modules. A camera module may include an array camera having an array of lenses and a corresponding array of image sensors. The array of image sensors may include a monochromatic image sensor such as a green image sensor and a polychromatic image sensor such as a red and blue image sensor. The red and blue image sensor may include a color filter array of red and blue color filter elements formed over an array of image pixels. The red and blue color filter elements in the polychromatic image sensor may be arranged in a checkerboard pattern, a zigzag pattern that extends vertically from the top of the pixel array to the bottom of the pixel array, or a diagonal strip pattern. The electronic device may include processing circuitry for combining monochromatic images from the monochromatic image sensor with polychromatic images from the polychromatic image sensor.
1. An imaging device, comprising:
a monochromatic image sensor having a first array of image pixels, wherein the image pixels in the first array of image pixels are diamond-shaped image pixels;
a polychromatic image sensor comprising:
a second array of image pixels, wherein the image pixels in the second array of image pixels are diamond-shaped image pixels; and
a color filter array formed over the second array of image pixels and comprising red and blue color filter elements, wherein the red color filter elements are arranged to form red diagonal stripes of contiguous red color filter elements that extend diagonally from a first edge of the second array to a second edge of the second array, wherein the blue color filter elements are arranged to form blue diagonal stripes of contiguous blue color filter elements that extend diagonally from the first edge of the second array to the second edge of the second array, and wherein the red diagonal stripes alternate with the blue diagonal stripes; and
processing circuitry configured to combine monochromatic image data from the monochromatic image sensor with polychromatic image data from the polychromatic image sensor to form full-color images, wherein the monochromatic image sensor and the polychromatic image sensor have an associated pixel pitch, wherein the processing circuitry interpolates missing pixel data to form the full-color images, and wherein a maximum interpolation distance is √{square root over (5)} times the pixel pitch.
2. The imaging device defined in claim 1 wherein the monochromatic image sensor comprises a clear color filter formed over the first array of image pixels.
3. The imaging device defined in claim 1 wherein the monochromatic image sensor comprises a green color filter formed over the first array of image pixels.
4. An imaging device, comprising:
a green image sensor having a first array of image pixels and a green color filter formed over the first array of image pixels;
a red and blue image sensor having a second array of image pixels and a color filter array formed over the second array of image pixels, wherein the color filter array comprises red and blue color filter elements, wherein the green image sensor and the red and blue image sensor are operable in high-dynamic-range mode in which alternating rows of image pixels in each of the first and second arrays are exposed for different lengths of time in a given imaging frame; and
processing circuitry configured to combine green image data from the green image sensor with red and blue image data from the red and blue image sensor to form full-color images, wherein the green image sensor and the red and blue image sensor have an associated pixel pitch, wherein the processing circuitry interpolates missing pixel data to form the full-color images, and wherein a maximum interpolation distance is √{square root over (5)} times the pixel pitch.
5. The imaging device defined in claim 4 wherein the image pixels in the first and second arrays of image pixels are diamond-shaped image pixels.
6. The imaging device defined in claim 5 wherein the red color filter elements and the blue color filter elements are interspersed among each other in a checkerboard pattern.
7. The imaging device defined in claim 5 wherein the red color filter elements and the blue color filter elements are arranged in respective groups of red color filter elements and groups of blue color filter elements, wherein each group of red color filter elements and each group of blue color filter elements forms a zigzag pattern that extends from an upper edge of the second array to a lower edge of the second array, and wherein the groups of red color filter elements are interleaved with the groups of blue color filter elements.
8. The imaging device defined in 5 wherein the red color filter elements are arranged to form red diagonal stripes that extend diagonally from a first edge of the second array to a second edge of the second array, wherein the blue color filter elements are arranged to form blue diagonal stripes that extend diagonally from the first edge of the second array to the second edge of the second array, and wherein the red diagonal stripes alternate with the blue diagonal stripes.
9. A system, comprising:
a central processing unit;
memory;
input-output circuitry; and
an imaging device, wherein the imaging device comprises:
a monochromatic image sensor having a first array of image pixels, wherein the image pixels in the first array of image pixels are diamond-shaped image pixels;
a polychromatic image sensor comprising:
a second array of image pixels, wherein the image pixels in the second array of image pixels are diamond-shaped image pixels; and
a color filter array formed over the second array of image pixels and comprising red and blue color filter elements, wherein the red color filter elements and the blue color filter elements are arranged in respective groups of red color filter elements and groups of blue color filter elements, wherein each group of red color filter elements and each group of blue color filter elements forms a zigzag pattern that extends from an upper edge of the second array to a lower edge of the second array, wherein each red color filter element within each group of red color filter elements shares a side with at least one other red color filter element, and wherein the groups of red color filter elements are interleaved with the groups of blue color filter elements; and
processing circuitry configured to combine monochromatic image data from the monochromatic image sensor with polychromatic image data from the polychromatic image sensor to form full-color images, wherein the monochromatic image sensor and the polychromatic image sensor have an associated pixel pitch, wherein the processing circuitry interpolates missing pixel data to form the full-color images, and wherein a maximum interpolation distance is √{square root over (5)} times the pixel pitch.
10. The system defined in claim 9 wherein the monochromatic image sensor comprises a green image sensor having a green color filter formed over the first array of image pixels.
11. The imaging device defined in claim 1 , wherein each of the blue color filter elements shares a side with at least one other blue color filter element.
12. The imaging device defined in claim 1 , wherein each of the red color filter elements shares a side with at least one other red color filter element.