Imaging systems with digitally controlled analog offset compensation

摘要

An image sensor may be provided that includes an image pixel array, analog column circuitry and digital column circuitry. The digital column circuitry may extract a systematic analog signal offset from data received from the analog column circuitry. The digital column circuitry may generate analog signal offset correction values based on the systematic analog signal offsets and provide the analog signal offset correction values to the analog column circuitry. The analog column circuitry may remove signal offsets from subsequently read out image data from the image pixel array using the analog signal offset correction values provided by the digital column circuitry. The image pixel array may include image pixels having color filters of various colors. The digital column circuitry may generate analog signal offset correction values corresponding to each of the various colors.

主权项

1. A method of generating offset-compensated image data using an image sensor with an array of image pixels arranged in pixel rows and pixel columns, analog column circuitry coupled to the pixel columns, and digital column circuitry coupled to the analog column circuitry, the method comprising:
with the analog column circuitry, providing image data from a portion of the image pixels to the digital column circuitry; with the digital column circuitry, extracting signal offset correction values from the provided image data; with the digital column circuitry, providing the extracted signal offset correction values to the analog column circuitry; and with the analog column circuitry, removing signal offsets from additional image data using the provided offset correction values to form offset-compensated analog image signals.