Systems and methods for processing pre-multiplied alpha content
AssigneeApple Inc.
InventorsVincent Z Young, Mahesh B Chappalli, Bartosz Ciechanowski
Life of this patent
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Abstract
This disclosure is directed toward systems and methods of pre-multiplied alpha handling during image processing operations. The image processing circuitry may include hardware that enables removal and insertion of pre-multiplied alpha content into red, green, blue (RGB) pixel values during gamma and scaling operations. The division by alpha and multiplication by alpha hardware may enable removal of pre-multiplied alpha content to RGB pixel values prior to gamma operations and insertion of pre-multiplied alpha content into RGB pixel values prior to scaling operations.
Claims20
An electronic device comprising:
- an electronic display configured to display an image based at least in part on processed image data;
- and
- image processing circuitry configured to:
- receive a plurality of sub-pixel values comprising red, green, blue (RGB) pixel values that are pre-multiplied by an alpha pixel value;
- divide each of the RGB pixel values of the plurality of sub-pixel values by the alpha pixel value to remove the pre-multiplied alpha pixel value;
- and
- apply a fixed de-gamma function to each of the RGB pixel values with the pre-multiplied alpha pixel value removed.
An electronic device comprising:
- an electronic display configured to display an image based at least in part on processed image data;
- and
- image processing circuitry configured to:
- receive a plurality of sub-pixel values comprising pixel values that include are pre-multiplied by an alpha pixel value;
- divide each of the pixel values of the plurality of sub-pixel values by the alpha pixel value to remove the pre-multiplied alpha pixel value;
- and
- apply one or more image processing operations to each of the pixel values of the plurality of sub-pixel values with the pre-multiplied alpha pixel value removed.
An electronic device comprising:
- an electronic display configured to display an image based at least in part on processed image data;
- and
- memory-to-memory scaler and rotator (MSR) circuitry configured to:
- receive a plurality of sub-pixel values comprising red, green, blue (RGB) pixel values that include a pre-multiplied alpha pixel value;
- divide each of the RGB pixel values of the plurality of sub-pixel values by an alpha pixel value to remove the pre-multiplied alpha pixel value;
- and
- apply a fixed de-gamma function to each of the RGB pixel values with the pre-multiplied alpha pixel value removed.
Dependencies are inferred from the claim text.