Systems and methods for statistics collection using pixel mask

An electronic device comprising:

• an image sensor configured to obtain a first frame of image data comprising a first plurality of pixels;
• a storage configured to store a second frame of image data comprising a second plurality of pixels;
• and
• an image signal processor configured to receive and process the first plurality of pixels or the second plurality of pixels, or both, wherein the image signal processor comprises:
• statistics collection logic configured to:
• receive a first instance of the first or second plurality of pixels;
• perform a first plurality of sequential processing operations on the pixels;
• and
• obtain at least one set of image statistics by:
• weighting the pixels using a two-dimensional weighting mask that comprises a lookup table indexed based at least partly on first and second chroma components of the pixels to obtain weighted pixel values;
• and
• accumulating the weighted pixel values;
• and
• an image processing pipeline configured to
• receive a second instance of the first or second plurality of pixels;
• and
• perform a second plurality of sequential operations on the pixels using the at least one set of image statistics from the statistics collection logic during at least one of the operations.

A method comprising:

• using image statistics collection logic of an image signal processor:
• receiving a pixel of a first RGB format into the image statistics collection logic;
• converting the pixel of the first RGB format into a pixel of a second RGB format and a pixel of a first luma and chroma format that includes a first chroma component and a second chroma component;
• determining a pixel weight using a two-dimensional pixel weighting mask that comprises a lookup table indexed by a first index value and a second index value, wherein the first index value is based at least partly on the first chroma component and wherein the second index value is based at least partly on the second chroma component;
• weighting, using the determined pixel weight, the pixel of the second RGB format or the pixel of the first luma and chroma format to obtain at least one accumulation value;
• and
• using the at least one accumulation value to obtain a tile accumulation statistic, a window accumulation statistic, or a combination thereof.

A method comprising:

• using statistics collection logic of an image signal processor to obtain statistics for pixels of a tile or window, or both, by:
• inputting the pixels of the tile or window, or both, one-by-one into a pixel weighting mask;
• determining whether the pixel weighting mask is enabled or disabled;
• when the pixel weighting mask is disabled, determining a pixel weighting value of 1 for all input pixels;
• when the pixel weighting mask is enabled, determining the pixel weighting value of each input pixel using the pixel weighting mask by:
• determining a first chroma index by scaling, offsetting, or scaling and offsetting, a first chroma component of the input pixel;
• determining a second chroma index by scaling, offsetting, or scaling and offsetting, a second chroma component of the input pixel;
• and
• when the first chroma index value is within a range of acceptable values, the second chroma index value is within a range of acceptable values, and a luma component of the input pixel is within a range of acceptable values, indexing a lookup table of the pixel weighting mask to the first chroma index and the second chroma index to obtain the pixel weighting value;
• weighting the input pixel by the pixel weighting value to obtain a weighted pixel value;
• and
• accumulating the weighted pixel value to obtain a pixel mask sum.