Method and apparatus for white balancing digital images
AssigneeATI Technologies, Inc.
InventorsSergiu Goma, Milivoje Aleksic
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Abstract
At least one illuminant white point estimate is determined in a color space having radially defined saturation based on a reference image. A chromatic adaptation correction vector (CACV) is determined based on the at least one illuminant white point estimate. Corrected pixels are obtained by applying the CACV (preferably in a cone response color space using a correction matrix based on the CACV) to uncorrected image pixels corresponding to a target image, which may comprise the reference image or another image.
Claims23
A method for performing white balancing in a digital representation of a target image comprising uncorrected image pixels, the method comprising:
- determining, in a color space having radially defined saturation and based upon at least some of a plurality of reference pixels constituting a reference image, at least one illuminant white point estimate;
- determining a chromatic adaptation correction vector based on the at least one illuminant white point estimate;
- and
- applying the chromatic adaptation correction vector to at least some of the uncorrected image pixels to provide corrected pixels.
A circuit for white balancing in a digital representation of a target image comprising uncorrected image pixels, the circuit comprising:
- an illuminant white point estimation component operative to receive at least some of a plurality of reference pixels constituting a reference image and to determine, in a color space having radially defined saturation, at least one illuminant white point estimate based on the at least some of the plurality of reference pixels;
- and
- a chromatic adaptation component, coupled to the illuminant white point estimation component, operative to receive at least some of the uncorrected image pixels and to determine a chromatic adaptation correction vector based on the at least one illuminant white point estimate and to apply the chromatic adaptation correction vector to the at least some of the uncorrected image pixels to provide corrected pixels.
A device capable of white balancing a digital representation of a target image comprising uncorrected image pixels, the device comprising:
- at least one image sensor that first provides a digital representation of a reference image comprising a plurality of reference pixels and subsequently provides the digital representation of the target image;
- a memory component;
- and
- a color processing circuit, in communication with the at least one image sensor and the memory component, operative to determine, in a color space having radially defined saturation, at least one illuminant white point estimate based on at least some of the plurality of reference pixels and to determine a chromatic adaptation correction vector based on the at least one illuminant white point estimate, and subsequently to apply the chromatic adaptation correction vector to the at least some of the uncorrected image pixels, thereby providing corrected pixels, prior to storing any pixels corresponding to the target image in the memory component.
An image comprising a plurality of corrected pixels, said image generated in accordance with a method for performing balancing, said method comprising:
- applying a chromatic adaptation correction vector to at least a portion of an uncorrected image to provide said plurality of corrected pixels, said uncorrected image comprising a plurality of uncorrected pixels;
- and
- wherein said chromatic correction vector was generated by using, in a color space having radially defined saturation, at least some of said plurality of uncorrected pixels.
In a device, a method for receiving an image, the method comprising:
- receiving the image that comprises at least one corrected pixel,
- wherein the at least one corrected pixel is provided by applying a chromatic adaptation correction vector to at least a portion of an uncorrected image to provide said at least one corrected pixel, said uncorrected image comprising a plurality of uncorrected pixels,
- and wherein said chromatic correction vector was generated using, in a color space having radially defined saturation, at least some of said plurality of uncorrected pixels.
In a device, a method for transmitting an image, the method comprising:
- transmitting the image that comprises at least one corrected pixel,
- wherein the at least one corrected pixel is provided by applying a chromatic adaptation correction vector to at least a portion of an uncorrected image to provide said at least one corrected pixel, said uncorrected image comprising a plurality of uncorrected pixels,
- and wherein said chromatic correction vector was generated using, in a color space having radially defined saturation, at least some of said plurality of uncorrected pixels.
Dependencies are inferred from the claim text.