Method of operating an image sensor having a digital exposure circuit
AssigneeRound Rock Research, LLC
InventorsEric R. Fossum, Alexander I. Krymski, Roger A. Panicacci, Christopher Clark
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Abstract
Automatic exposure adjusting device considers the image on a pixel-by-pixel basis. Each pixel is characterized according to its most significant bits. After the pixels are characterized, the number of pixels in any particular group is counted. That counting is compared with thresholds which set whether the image is over exposed, under exposed, and can optionally also determine if the image is seriously over exposed or seriously under exposed. Adjustment of the exposure is carried out to bring the image to a more desired state.
Claims21
(canceled)
A method of operating a device comprising:
- counting a number of digital values indicating an overexposed pixel output during at least one image frame;
- counting a number of digital values indicating an underexposed pixel output during said at least one image frame;
- comparing results of said first and second counters with predetermined thresholds;
- and
- determining whether to increase, decrease, or maintain an exposure of a subsequent frame of said image sensor based on comparison results from the at least one comparator.
A method of controlling exposure comprising:
- obtaining a plurality of digital values from a current image frame representing values of pixels of an image sensor;
- reviewing a plurality of digital values representing values of pixels of an image sensor;
- comparing the digital values with predetermined threshold values;
- determining if each digital value in said plurality of digital values indicates an overexposed pixel or an underexposed pixel;
- and
- adjusting exposure of a subsequent frame of said image sensor according to said determination.
Dependencies are inferred from the claim text.