Extended dynamic range image sensor

Abstract

A method for correcting a fixed pattern noise associated with an image sensor having two or more pixels and a charge control structure for changing a charge capacity of the two or more pixels during an integration time, the method comprising: setting the charge capacity of each pixel to substantially zero at a beginning of an integration time; changing the charge capacity of each pixels throughout the integration time such that substantially no portion of the pixel photo response curve is substantially linear; and multiplying each pixel by a constant value determined for that pixel to compensate for variations of the charge capacity.

Description

technical field [0001] The invention relates to the field of image sensors having a plurality of pixels which can change their charge during accumulation, thereby increasing the extended dynamic range. Background technique [0002] When people observe the real world, the eyes are able to see a wide range of brightness levels. When looking at pictures of the same scene, one would expect to see the same range. But people often forget that when he is looking at the real world, when he looks at the bright area and then looks at the dark area, the eye will constantly adjust the light intensity through the iris. When the outside world is bright sunlight, no matter how hard the eye tries, the bright sunlight prevents the eye from seeing details that are in the shadows. Photos, however, are able to bring out details in the shadows. However, photographic paper is unlikely to reflect enough light to achieve the range of brightness levels produced by the sun. The proposed solution ...

AI Technical Summary

Problems solved by technology

This consumes a large portion of the memory and is therefore the main reason why this technique cannot be widely used

[0012] In summary, the prior art does not provide a simple method that can eliminate the fixed pattern noise

Images