Abstract:
CMOS image sensor with LED flickering reduction and low color cross-talk are disclosed. In one embodiment, an image sensor includes a plurality of pixels arranged in rows and columns of a pixel array that is disposed in a semiconductor substrate. Each pixel includes a plurality of large subpixels (LPDs) and at least one small subpixel (SPD). A plurality of color filters are disposed over individual subpixels. Each individual SPD is laterally adjacent to at least one other SPD.
Abstract:
CMOS image sensor with multiple sensitivities for high dynamic range imaging and LED flicker mitigation. In one embodiment, an image sensor includes a plurality of pixels arranged in rows and columns of a pixel array that is disposed in a semiconductor substrate. Each pixel includes a plurality of cells. A plurality of color filters is disposed over corresponding plurality of cells. The plurality of color filters corresponding to the plurality of cells of an individual pixel have more than one filtering strength for each color of the plurality of color filters.
Abstract:
A method of white balancing an image includes mapping pixels of the image to a color space diagram. Each of the pixels of the image include a red (“R”), a green (“G”), and a blue (“B”) subvalue. A first central tendency of each of the RGB subvalues of pixels mapped in a first pre-defined region of the color space diagram is determined and a second central tendency of each of the RGB subvalues of pixels mapped in a second pre-defined region of the color space diagram is determined. The first pre-defined region is associated with a first illuminating source and the second pre-defined region is associated with a second illuminating source. RGB values of a white pixel are generated based on the first and second central tendencies.
Abstract:
In an embodiment, an image sensor comprises a pixel array having a minimal repeating unit, where the minimal repeating unit consists of 4×4 pixels including 12 green pixels, 2 blue pixels, and 2 red pixels, where a minimal repeating unit is immediately next to another minimal repeating unit in row and column directions. In another embodiment, an image sensor comprises a pixel array having a minimal repeating unit, where the minimal repeating unit consists of 8×8 pixels including 48 green pixels, 8 blue pixels, and 8 red pixels.
Abstract:
CMOS image sensor with LED flickering reduction and low color cross-talk are disclosed. In one embodiment, an image sensor includes a plurality of pixels arranged in rows and columns of a pixel array that is disposed in a semiconductor substrate. Each pixel includes a plurality of large subpixels (LPDs) and at least one small subpixel (SPD). A plurality of color filters are disposed over individual subpixels. Each individual SPD is laterally adjacent to at least one other SPD.
Abstract:
A method for demosaicing a raw image includes: (1) horizontally-interpolating a green channel formed of primary pixel-values Bg(x,y)g to yield a horizontally-interpolated green channel that includes both Bg(x,y)g and non-primary pixel-values Igh(x,y)r,b; (2) modifying each Igh(x,y)r,b, by horizontally-neighboring pixel-values, to yield a refined horizontally-interpolated green channel; (3) vertically-interpolating the green channel to yield a vertically-interpolated green channel that includes pixel-values Igv(x,y)r,b; (4) modifying each Igv(x,y)r,b by vertically-neighboring pixel-values, to yield a refined vertically-interpolated green channel; (5) generating a full-resolution green channel from the refined interpolated green channels and gradients thereof; (6) generating a full-resolution red channel by determining red pixel-values from a local-red mean value of neighboring pixel-values and the full-resolution green channel; (7) generating a full-resolution blue channel by determining pixel-values from a local-blue mean value of neighboring pixel-values and the full-resolution green channel; and (8) combining the full-resolution channels to yield a demosaiced raw image.
Abstract:
A brightness-sensitive automatic white balance method includes (a) determining the brightness of a scene captured in an electronic color image, (b) selecting a color-weighting map based upon the brightness of the scene, (c) extracting auto white balance parameters from the color-weighting map, and (d) white balancing the electronic color image according to the auto white balance parameters. An adaptive automatic white balance method includes (a) refining, based upon a first electronic color image of a scene illuminated by an illuminant of a first spectral type, a color-weighting probability distribution for the illuminant of the first spectral type, wherein the color-weighting probability distribution may be brightness-specific, (b) extracting auto white balance parameters from the refined color-weighting probability distribution, and (c) white balancing, according to the auto white balance parameters, an electronic color image of a scene illuminated by the illuminant of the first spectral type.
Abstract:
An image sensor has a plurality of pixels arranged in a row direction and in a column direction. Each pixel comprises a color filter that has a portion with a low transmissivity and a portion with a high transmissivity, and a photoelectric conversion element that includes a first photoelectric conversion cell which receives light transmitting through the portion with the low transmissivity of the color filter, and a second photoelectric conversion cell which receives light transmitting through the portion with the high transmissivity of the color filter. The plurality of pixels are arranged such that positions of the portions with the low transmissivity for pixels of one color are identical among the plurality of pixels, and the portions with the low transmissivity are positioned adjacent to each other between adjacent pixels of different colors in the row direction only.
Abstract:
A method for capturing a high-dynamic-range image includes: (i) storing a plurality of pixel values representing a first image captured by an image sensor that includes a pixel array, each pixel value having been generated by a respective pixel of a pixel subarray of the pixel array, each pixel being set to one of N1 first exposure values, N1≥1; (ii) determining an exposure-count N2 based on the plurality of pixel values; (iii) setting each pixel to one of a second plurality of exposure values, N2 in number, such that, for each of the second plurality of exposure values, at least one pixel is set to that exposure value, one of the second plurality of exposure values differing from each of the N1 first exposure values by more than a threshold value; and after setting (iv), capturing a second image with the image sensor.
Abstract:
An image sensor includes a pixel array, and a first, second, and an intermediate memory-element. The memory-elements store, respectively, a first, second, and an intermediate exposure value. The pixel array includes pixel-subarrays each including a rescue pixel and a first, second, and third plurality of contiguous pixels. Each of the first plurality of pixels is connected to the first memory-element and spans diagonally-opposite corners of the pixel-subarray. Each of the second plurality of pixels is connected to the second memory-element and located on a first side of the first plurality of pixels. Each of the third plurality of pixels is connected to the second memory-element and located on a second side of the first plurality of pixels. The rescue-pixel is connected to the intermediate memory-element and is (i) located on one of the first side and the second side and/or (ii) adjacent to one of the first plurality of pixels.