公开(公告)号：US06822766B2

公开(公告)日：2004-11-23

申请号：US09797268

申请日：2001-03-01

Applicant: Edward A. Hill ,  Craig T. Johnson ,  Carolyn L. Harris ,  William D. Amidei

Inventor： Edward A. Hill ,  Craig T. Johnson ,  Carolyn L. Harris ,  William D. Amidei

IPC: H04N100

CPC classification number: H04N1/401

Abstract: A circuit connected to a linear array of photosensors generates image data representative of information printed on a document and adjusts the gains applied to the outputs of selected ones of the photosensors to eliminate streaks in the image data otherwise due to the selected photosensors imaging debris on an optical reference surface. The circuit determines which photosensors have low output values during a factory scan of a clean white reference surface. During a subsequent user environment calibration scan, low output values are adjusted to the average of their neighbors, but only for locations not identified as having low outputs during the factory scan. The circuit additionally performs a PRNU compensation and further adjusts the gains applied to each of the outputs of the photosensors so that all of their output values have a substantially uniform value.

Abstract translation: 连接到光电传感器的线性阵列的电路产生表示打印在文档上的信息的图像数据，并且调整应用于所选择的光电传感器的输出的增益以消除图像数据中的条纹，否则由于所选择的光电传感器成像碎片在 光学参考面。 该电路确定在干净的白色参考表面的工厂扫描期间哪些光电传感器具有低输出值。 在随后的用户环境校准扫描期间，将低输出值调整为其邻居的平均值，但仅对于在工厂扫描期间未被识别为具有低输出的位置。 该电路还执行PRNU补偿，并进一步调整施加到光电传感器的每个输出的增益，使得它们的所有输出值具有基本均匀的值。