Patent ID: 9681071
Date: 2017-06-13
CPC Classifications: H01L,H04N

Claim:
1. A method of operation within an integrated-circuit image sensor having a pixel array, the method comprising: determining, for each of a plurality of pixels within the pixel array, whether the pixel is an overthreshold pixel or underthreshold pixel according to whether charge integrated within the pixel in response to incident light during a first interval exceeds or does not exceed a first threshold, respectively; conditionally generating, for each overthreshold pixel, a respective N-bit digital sample corresponding to the charge integrated within the pixel during the first interval; accessing a first lookup table using the N-bit digital sample generated for each overthreshold pixel to retrieve, as a representative value for the overthreshold pixel, one of a plurality of M-bit digital values that corresponds to a stepwise range of charge integration levels, M being less than N and the plurality of M-bit digital values excluding one or more reserved M-bit digital values such that the plurality of M-bit digital values consists of fewer than 2 assigning, as a representative value for each underthreshold pixel, a first one of the one or more reserved M-bit digital values.