Calibration system and method for color image scan

专利名称：Calibration system and method for color

image scanning

发明人：Smyth, William K.申请号：EP90114601.9申请日：19900730公开号：EP0415100A3公开日：19910410

专利附图：

摘要：A system and method for calibrating signals provided by individual cells in aphotodetector array scanned by light originating at a low-cost variable light source andreflected from a subject to be replicated in digital form by processing photodetector cell

signals in a manner so that individual cell signals are corrected to compensate forfluctuations in source light. The system and method is particularly applicable to a colorbalanced photodetector array in which individual photodetectors are arranged in setswith each set having a variable number of rows oriented in a direction transverse to thedirection of scan and columns parallel to the direction of scan. The invention is practicedby exposing the first few photodetectors in each row to the full spectrum of visible lightreflected from a white reference patch. During processing, as the photodetector signalsare sequentially transferred, to a processor, the signals provided by the cells exposed tothe white reference are compared with a fixed value to obtain a calibration factor. As thesignals develop by cells in the same set but as a result of exposure to light reflectedfrom the subject image, those signals are multiplied by the calibration factor so that theprocess signals are corrected for variations in source light on a real time basis.

申请人：POLAROID CORPORATION

地址：549 Technology Square Cambridge, Massachusetts 02139 US

国籍：US

代理机构：Koch, Günther, Dipl.-Ing.

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