Digital exposure circuit for an image sensor
First Claim
Patent Images
1. 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 with programmable thresholds; and
a decision element for making a decision to either increase, decrease, or maintain an exposure of a next frame of said image sensor based on comparison results from the at least one comparator.
1 Assignment
0 Petitions
Accused Products
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.
-
Citations
16 Claims
-
1. 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 with programmable thresholds; and a decision element for making a decision to either increase, decrease, or maintain an exposure of a next frame of said image sensor based on comparison results from the at least one comparator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. 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 said plurality of digital values 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 with programmable thresholds; and adjusting exposure of a next frame of said image sensor according to said comparison. - View Dependent Claims (11, 12, 13, 14, 15, 16)
-
Specification