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US 11,308,589 B2Granted
Devices, systems, and methods for enhancing images
AssigneeCanon Virginia, Inc.
InventorsYunzhe Zhao, Bradley Scott Denney
Life of this patent
Estimating the term…
Abstract
Devices, systems, and methods obtain an image; perform at least one nonlinear locally-adaptive mapping on the image, thereby generating a revised image; generate an edge-enhanced image based on the revised image; and perform dynamic contrast stretching on the edge-enhanced image, thereby generating an enhanced image.
Claims18
A method comprising:
- obtaining an initial image that is defined in an image space;
- performing, in the image space, at least one nonlinear locally-adaptive mapping on the initial image, thereby generating a revised image in the image space, wherein the at least one nonlinear locally-adaptive mapping on the initial image includes a first nonlinear locally-adaptive mapping on the initial image in the image space that generates a first revised value for pixel p in the initial image based on the following:
- a value of pixel p in the initial image, respective values of pixels in a neighborhood of pixel p in the initial image, a maximum value of respective values of all pixels in the initial image, and a central tendency of the respective values of all the pixels in the initial image;
- performing, in the image space, edge enhancement on the initial image, thereby generating an edge-enhanced image in the image space;
- generating a synthesized image based on the edge-enhanced image and on the revised image;
- and
- performing, in the image space, dynamic contrast stretching on the revised image in the image space, thereby generating an enhanced image in the image space.
4 more elements
A device comprising:
- one or more computer-readable media storing instructions;
- and
- one or more processors that are configured to communicate with the one or more computer-readable media to execute the instructions to cause the device to perform operations comprising:
- obtaining an image that is defined in an image space;
- performing, in the image space, one or more nonlinear locally-adaptive mappings on the image, thereby generating a revised image in the image space, wherein performing the one or more nonlinear locally-adaptive mappings on the image includes generating a respective scaling factor for each pixel in the image and multiplying each pixel's respective value by the pixel's respective scaling factor;
- performing an inverse tone mapping on the image, thereby generating an inverse-tone-mapped image;
- generating an adjusted-dynamic-range image in the image space based on the revised image in the image space and on the inverse-tone-mapped image;
- synthesizing the revised image and the adjusted-dynamic-range image, thereby generating a synthesized image;
- and
- performing dynamic contrast stretching on the synthesized image.
7 more elements
One or more non-transitory computer-readable media storing instructions that, when executed by one or more computing devices, cause the one or more computing devices to perform operations comprising:
- obtaining an image that is defined in an image space;
- performing, in the image space, a first nonlinear locally-adaptive mapping on the image, thereby generating an interim image in the image space, wherein performing the first nonlinear locally-adaptive mapping on the image includes generating a respective scaling factor for each pixel in the image and multiplying each pixel's respective value by the pixel's respective scaling factor;
- performing, in the image space, a second nonlinear locally-adaptive mapping on the interim image in the image space, thereby generating a revised image;
- enhancing one or more edges in the image, thereby generating an edge- enhanced image;
- and
- generating a synthesized image based on the edge-enhanced image and on the revised image,
- wherein an output pixel value of the first nonlinear locally-adaptive mapping on the image can be described by the following:
- y
- temp
- =
- (
- max
-
- (
- I
- i
-
-
- n
- )
- +
- f
- +
- a
-
-
- 1
- )
-
- x
- x
- +
- f
- +
- a
-
-
- 1
- ,
-
- where
-
-
- f
- =
- LP
-
- (
- x
- )
- +
- mean
-
-
- (
- I
- i
-
-
- n
- )
- 2
- ,
- where ytemp is the output pixel value of the first nonlinear locally-adaptive mapping, where Iin is the image, where x is a pixel value in the image Iin, where max(Iin) is a maximum pixel value in the image, where a1 is a strength-control parameter, where mean(Iin) is a central tendency of all pixel values in the image, and where LP(x) is a value at the pixel after the image has been convolved with a low-pass filter.
61 more elements
Dependencies are inferred from the claim text.