Exposure correction for scanners

摘要

A method and apparatus for exposure correction in scanners are disclosed. In the method, exposure is corrected for pixels received in an image sensor array. Exposure time is tracked for the incoming pixel data and a calibration factor is determined for correcting the gain, and the calibration factor is adjusted based on the tracked exposure time. In the apparatus, a scanner includes an illumination source and a sensor for receiving pixel data. Using values stored in a memory, circuitry is provided for determining a calibration factor, for tracking exposure time for the pixel data and for adjusting the pixel data based on the calibration factor and exposure time.

主权项

1. A controller for correcting for inconsistencies in a scanner, the controller comprising:
an interface with a sensor, the sensor configured to sense an image exposed by an illumination source for a duration of an exposure time; wherein the controller is configured to:
receive pixel data generated based on the image sensed by the sensor;measure the duration of the exposure time according to a non-dithered reference clock that is different from a dithered system clock;determine an exposure correction factor based on the measured exposure time; andcompensate for inconsistencies in the pixel data according to the exposure correction factor, wherein the controller is configured to be timed using a system clock signal from the dithered system clock that is different from the reference clock.