Methods and apparatus for reducing spatial flicker artifacts
AssigneeSemiconductor Components Industries, LLC
InventorsManjunath SOMAYAJI, Rohit RANADE
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Abstract
Various embodiments of the present technology may comprise a method and apparatus for reducing spatial flicker artifacts in high dynamic range images produced from multiple image captures with differing integration times. The method and apparatus may comprise, in the image captures, measuring pixel intensity selecting pixels with a predetermined intensity thresholds, calculating a ratio based on a channel selection, normalizing the calculated ratio to an ideal ratio, and applying the normalized ratio to corresponding image pixels in a second image capture to produce a flicker-free image.
Claims20
An imaging device comprising:
- an array of pixels arranged in rows and columns, wherein the array of pixels generates:
- first image pixel data corresponding to pixels having a first exposure time, and second image pixel data corresponding to pixels having a second exposure time,
- wherein the first and second image pixel data are derived from the same spatially located pixels;
- and
- an image signal processor coupled to the array of pixels, wherein the image signal processor:
- receives the first image pixel data and second image pixel data;
- identifies valid and invalid image pixel data based on pixel data values;
- computes a ratio utilizing the valid image pixel data;
- normalizes the ratio to an ideal ratio;
- and
- modifies the second image pixel data according to the normalized ratio.
A method for reducing spatial artifacts in multi-exposure images comprising:
- generating, with an image sensor comprising an array of pixels arranged in rows and columns, first image pixel data corresponding to pixels having a first exposure time, and second image pixel data corresponding to pixels having a second exposure time, wherein the first and second image pixel data are derived from the same spatially located pixels;
- wherein the first and second image pixel data comprise a value representing light intensity;
- identifying whether the value is one of a valid or an invalid image pixel data;
- computing a ratio utilizing the valid image pixel data;
- utilizing an ideal ratio to compute a normalized ratio;
- and
- modifying the second image pixel data according to the normalized color ratio.
A system for producing flicker-free images of a scene illuminated by a light using an alternating current source, comprising:
- an image sensor, comprising a color filter array situated on an array of pixels arranged in rows and columns, wherein the image sensor obtains:
- first image pixel data corresponding to pixels having a first exposure time, and second image pixel data corresponding to pixels having a second exposure time;
- wherein the first and second image pixel data are derived from the same spatially located pixels;
- a storage unit coupled to the image sensor, wherein the storage unit stores the first and second image pixel data;
- an image signal processor coupled to the storage unit, wherein the image signal processor:
- identifies valid and invalid image pixel data based on a pixel data value;
- computes a color ratio utilizing the valid image pixel data;
- utilizes an ideal ratio to compute a normalized color ratio;
- and
- modifies the second image pixel data according to the normalized color ratio to form corrected image pixel data;
- combines the corrected image pixel data with the first image pixel data to form a multi-pixel data image;
- and
- an I/O device for displaying the multi-pixel data image.
Dependencies are inferred from the claim text.