Digital exposure circuit for an image sensor
AssigneeRound Rock Research, LLC
InventorsEric R. Fossum, Alexander L. 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.
Claims20
1-21. (canceled)
A device comprising:
- a first counter which counts a number of digital values indicating an overexposed pixel output during at least one image frame;
- a second counter which counts a number of digital values indicating an underexposed pixel output during said at least one image frame;
- at least one comparator for comparing results of said first and second counters;
- and
- a decision element for making a decision to either 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:
- reviewing a plurality of digital values representing values of pixels of an image sensor to determine if each digital value in said plurality of digital values indicates an overexposed pixel or an underexposed pixel;
- comparing results of said determination;
- and
- adjusting exposure of a subsequent frame of said image sensor according to said comparison.
Dependencies are inferred from the claim text.