Method and device for increasing the grey-scale resolution

摘要

The method is used for increasing the grey-scale resolution in the reproduction of an original image or the like scanned by means of a CCD sensor, in which method light incident into individual elements of the CCD sensor in each case from corresponding individual elements of the original image is converted into electric output signals which are used as a basis for the image reproduction. The reproduction of brighter portions of the original image is based on output signals which are generated by scanning the original image with light which produces a relatively lower charge integration in at least a part of the corresponding sensor elements. Correspondingly, darker portions of the original image are scanned with light which produces a relatively higher charge integration in at least a part of the sensor elements. The output signals used as a basis for the reproduction of the darker portions of the original image are subjected to a level correction. The original image is scanned at least twice, the light incident from the elements of the original image producing a different charge integration in the corresponding elements of the CCD sensor in each of the scanning processes. The scanning is done with different light intensity, the reproduction of brighter portions of the original image being based on output signals which are generated in corresponding elements of the CCD sensor during the scanning with a relatively lower light intensity. The reproduction... Original abstract incomplete.