System and method for adaptive local white balance adjustment

An apparatus comprising:

• an image sensor including a pixel array having a plurality of pixels;
• an automatic white balance (AWB) circuit coupled to the pixel array to:
• determine a local white balance component for each pixel using a spatial-domain function and an intensity-domain function, wherein the intensity-domain function decreases the weight of pixels within a local domain whose intensity differs greatly from the intensity of the pixel to which the white balance adjustment is being applied,
• determine a global white balance component for each pixel, and
• apply a white balance adjustment to each pixel, the applied white balance adjustment comprising a combination of the local white balance component and the global white balance component.

A system comprising:

• an optical element;
• an image sensor coupled to the optical element, the image sensor comprising a pixel array including a plurality of pixels;
• an automatic white balance (AWB) circuit coupled to the pixel array to:
• determine a local white balance component for each pixel using a spatial-domain function and an intensity-domain function, wherein the spatial-domain function decreases the weight of pixels within a local domain that are spatially distant from the pixel to which the white balance adjustment is being applied,
• determine a global white balance component for each pixel, and
• apply a white balance adjustment to each pixel, the applied white balance adjustment comprising a combination of the local white balance component and the global white balance component;
• and
• one or both of a display unit and a storage unit coupled to the digital signal processor.

A system comprising:

• an optical element;
• an image sensor coupled to the optical element, the image sensor comprising a pixel array including a plurality of pixels;
• an automatic white balance (AWB) circuit coupled to the pixel array to:
• determine a local white balance component for each pixel using a spatial-domain function and an intensity-domain function, wherein the intensity-domain function decreases the weight of pixels within a local domain whose intensity differs greatly from the intensity of the pixel to which the white balance adjustment is being applied,
• determine a global white balance component for each pixel, and
• apply a white balance adjustment to each pixel, the applied white balance adjustment comprising a combination of the local white balance component and the global white balance component;
• and
• one or both of a display unit and a storage unit coupled to the digital signal processor.

A process comprising:

• receiving image data from each pixel in a pixel array;
• determining a local white balance component for the image data from each pixel using a spatial-domain function and an intensity-domain function, wherein the spatial-domain function decreases the weight of pixels within a local domain that are spatially distant from the pixel to which the white balance adjustment is being applied;
• determining a global white balance component for the image data from each pixel;
• and
• applying a white balance adjustment to the image data from each pixel, the applied white balance adjustment comprising a combination of the local white balance component and the global white balance component.

A process comprising:

• receiving image data from each pixel in a pixel array;
• determining a local white balance component for the image data from each pixel using a spatial-domain function and an intensity-domain function, wherein the intensity-domain function decreases the weight of pixels within a local domain whose intensity differs greatly from the intensity of the pixel to which the white balance adjustment is being applied;
• determining a global white balance component for the image data from each pixel;
• and
• applying a white balance adjustment to the image data from each pixel, the applied white balance adjustment comprising a combination of the local white balance component and the global white balance component.