| 摘要 |
A CMOS imager includes a CMOS image sensor comprising an array of photoreceptors, a memory storing a reference operating level for the array, and readout circuitry for obtaining, at n-bit resolution, a photoreceptor reset value from the photoreceptors in the array. In addition, the CMOS imager includes comparison circuitry that determines a difference between the reference operating level and the photoreceptor reset value as well as matching circuitry that matches the difference against bins in a bin allocation. In particular, the bin allocation spans a photoreceptor noise range with the bins forming a quantization of the noise range into correction levels. Each of the correction levels may be associated with an m-bit correction code, where m is typically much less than n. As a result, the amount of memory necessary to store the correction codes is far less than that required to store full resolution (i.e., n-bit) values. The CMOS imager thereby achieves reduced noise image extraction from a CMOS image sensor with less complexity, less memory and less expense than convention correlated double sampling implementations.
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