发明名称 |
Raster input scanner calibration. |
摘要 |
<p>A raster input scanner (10) in which a dither generator (65) introduces a random error signal to artificially increase the calibration signal accuracy during calibration of the scanner. Calibration includes the following steps: a) scanning a calibration image of preset density to provide an image signal output from each of the array photosites; b) introducing a dither signal into the image signal output of each of said photosites to provide an artificially distorted image signal output from each of said photosites; c) converting the distorted image signals to digital signals; d) averaging a plurality of such artificially distorted signals from each of said photosites; e) determining a digital correction voltage for correcting non-uniform photosensors of the array; and f) converting the digital correction voltages to analog and adjusting the image signal outputs of the non-uniform photosites by combining the image signal output of each photosite with the corrective voltage for that photosensor. </p> |
申请公布号 |
EP0295873(A2) |
申请公布日期 |
1988.12.21 |
申请号 |
EP19880305431 |
申请日期 |
1988.06.15 |
申请人 |
XEROX CORPORATION |
发明人 |
WILLIAMS, LEON CALVIN;CLARK, RAYMOND JOHN |
分类号 |
H04N1/19;G06T1/00;H04N1/401 |
主分类号 |
H04N1/19 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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