Patent ID: 9654699
Date: 2017-05-16
CPC Classifications: H04N

Claim:
1. A method of reading out an array of image pixels that are capturing a high dynamic range (HDR) image having multiple exposure periods, the method comprising: writing a first, second, and third sub-frame to a memory at a first, second, and third readout time, respectively, the first, second, and third sub-frame being generated by a same first sub-array of the array of image pixels, wherein the third readout time is subsequent to the second readout time and the second readout time is subsequent to the first readout time, and wherein the first sub-frame is exposed for a first exposure period, the second sub-frame is exposed for a second exposure period shorter than the first exposure period, and the third sub-frame is exposed for a third exposure period shorter than the second exposure period; sending the first, second, and third sub-frame to an image signal processor at a first write time subsequent to the third readout time; and sending a fourth sub-frame to the image signal processor at a second write time subsequent to the third readout time, the fourth sub-frame being generated by the same first sub-array of the array of image pixels exposed for a fourth exposure period shorter than the third exposure period, wherein the fourth sub-frame bypasses the memory by being sent from an analog-to-digital converter to the image signal processor without being written to the memory, wherein the second write time is subsequent to the first write time, and wherein the first, second, third, and fourth sub-frame are received by the image signal processor sequentially, in that order, during the first write time and the second write time.