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US 6,788,822 B1Granted
Method and device for correcting lightness of image
AssigneesSharp Kabushiki Kaisha, Synthesis, Inc.
InventorsXiaomang Zhang, Noboru Kubo, Hiroyuki Okuhata, Akimasa Niwa
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Abstract
A method for correcting lightness of an image includes the steps of: calculating a first scale and a second scale based on an image scale of an original image from image information of the original image; multiscale retinex processing the original image with respect to the first scale and the second scale; and synthesizing a result of the multiscale retinex processing with the image information of the original image.
Claims8
A method for correcting lightness of an image, comprising the steps of:
- calculating a first scale and a second scale, which correspond to an inputted image size, based on an image scale of an original image including a plurality of pixels from image information of the original image;
- multiscale retinex processing the original image with respect to the first scale and the second scale to produce a multiscale retinex processing result;
- calculating an offset correction value based on a histogram of a lightness value against the number of pixels of the original image;
- correcting said multiscale retinex processing result based on a gain correction value and said offset correction value to produce a corrected multiscale retinex processing result;
- and
- synthesizing said corrected multiscale retinex processing result with the image information of the original image to produce an output image.
3 more elements
An image processing device, comprising:
- a scale size calculating section for calculating a first scale and a second scale, which correspond to an inputted image size, based on an image scale of an original image including a plurality of pixels from image information of the original image;
- a scale retinex processing section for multiscale retinex processing the original image with respect to the first scale and the second scale to produce a multiscale retinex processing result, and
- a correction value calculating section for calculating an offset correction value based on a histogram of a lightness value against the number of pixels of the original image,
- wherein said scale retinex processing section corrects said multiscale retinex processing result based on a gain correction value and said offset correction value to produce a corrected multiscale retinex processing result, and
- wherein said scale retinex processing section synthesizes said corrected multiscale retinex processing result with the image information, thereby generating an output image.
2 more elements
Dependencies are inferred from the claim text.