Illumination estimation for images
First Claim
Patent Images
1. A computer-implemented method of removing illumination variation from an image, the method performed by a computer and comprising:
- selecting an image containing varying illumination;
determining instances of a repeating pattern in the image;
calculating inverse illumination values for pixels at locations within instances of the repeating pattern responsive to pixel intensities of pixels at corresponding locations in other instances of the repeating pattern; and
for pixels in the image, multiplying a pixel intensity of a pixel by an inverse illumination value calculated for the pixel to remove the illumination variation from the image responsive to the calculation of the inverse illumination values.
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Accused Products
Abstract
An image comprising varying illumination is selected. Instances of a repeating pattern in the image is determined. Illumination values for pixels at locations within instances of the repeating pattern are calculated responsive to pixel intensities of pixels at corresponding locations in other instances of the repeating pattern. The varying illumination is removed form the image responsive to the illumination values.
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Citations
25 Claims
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1. A computer-implemented method of removing illumination variation from an image, the method performed by a computer and comprising:
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selecting an image containing varying illumination; determining instances of a repeating pattern in the image; calculating inverse illumination values for pixels at locations within instances of the repeating pattern responsive to pixel intensities of pixels at corresponding locations in other instances of the repeating pattern; and for pixels in the image, multiplying a pixel intensity of a pixel by an inverse illumination value calculated for the pixel to remove the illumination variation from the image responsive to the calculation of the inverse illumination values. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A computer program product having a non-transitory computer-readable storage medium storing computer-executable code for removing illumination variation from an image, the code when executed performs steps comprising:
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selecting an image containing varying illumination; determining instances of a repeating pattern in the image; calculating inverse illumination values for pixels at locations within instances of the repeating pattern responsive to pixel intensities of pixels at corresponding locations in other instances of the repeating pattern; and for pixels in the image, multiplying a pixel intensity of a pixel by an inverse illumination value calculated for the pixel to remove the illumination variation from the image responsive to the calculation of the inverse illumination values. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A computer system for removing illumination variation from an image, the system comprising:
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a computer processor; and a computer-readable storage medium storing computer-executable code configured to execute on the computer processor, the code when executed performs steps comprising; selecting an image containing varying illumination; determining instances of a repeating pattern in the image; calculating inverse illumination values for pixels at locations within instances of the repeating pattern responsive to pixel intensities of pixels at corresponding locations in other instances of the repeating pattern; and for pixels in the image, multiplying a pixel intensity of a pixel by an inverse illumination value calculated for the pixel to remove the illumination variation from the image responsive to the calculation of the illumination values. - View Dependent Claims (15, 16, 17, 18, 19)
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20. A computer-implemented method of removing illumination variation from an image, the method performed by a computer and comprising:
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selecting an image containing varying illumination; determining instances of a repeating pattern in the image; for each of a plurality of pixels in the image, calculating an illumination value for the pixel within an instance of the repeating pattern based at least in part on a difference between a pixel intensity of the pixel within the instance of the repeating pattern and a pixel intensity of a pixel at a corresponding location in an adjacent instance of the repeating pattern, wherein the calculation is performed as an optimization problem and wherein a mean pixel value for a defined region of the image is used as an initial value for the optimization problem; and removing the illumination variation from the image based on the calculation of the illumination values. - View Dependent Claims (21)
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22. A computer program product having a non-transitory computer-readable storage medium storing computer-executable code for removing illumination variation from an image, the code when executed performs steps comprising:
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selecting an image containing varying illumination; determining instances of a repeating pattern in the image; for each of a plurality of pixels in the image, calculating an illumination value for the pixel within an instance of the repeating pattern based at least in part on a difference between a pixel intensity of the pixel within the instance of the repeating pattern and a pixel intensity of a pixel at a corresponding location in an adjacent instance of the repeating pattern, wherein the calculation is performed as an optimization problem and wherein a mean pixel value for a defined region of the image is used as an initial value for the optimization problem; and removing the illumination variation from the image based on the calculation of the illumination values. - View Dependent Claims (23, 25)
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24. A computer system for removing illumination variation from an image, the system comprising:
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a computer processor; and a computer-readable storage medium storing computer-executable code configured to execute on the computer processor, the code when executed performs steps comprising; selecting an image containing varying illumination; determining instances of a repeating pattern in the image; for each of a plurality of pixels in the image, calculating an illumination value for the pixel within an instance of the repeating pattern based at least in part on a difference between a pixel intensity of the pixel within the instance of the repeating pattern and a pixel intensity of a pixel at a corresponding location in an adjacent instance of the repeating pattern, wherein the calculation is performed as an optimization problem and wherein a mean pixel value for a defined region of the image is used as an initial value for the optimization problem; and removing the illumination variation from the image based on the calculation of the illumination values.
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Specification