Apparatus and method for acquiring and evaluating an image from a predetermined extract of a printed product

摘要

An apparatus for acquiring and evaluating an image of a predetermined extract of a printed product removes the effects of scattered light to improve the accuracy of image evaluation. The apparatus uses a camera that has an electronic image sensor with a two-dimensional arrangement of sensor elements. An aperture stop is arranged in the beam path of the camera for shadowing a predetermined part of the image sensor. When an acquired image is read from a part of the image sensor that is not shadowed, corresponding readings from the shadowed portion of the sensor are subtracted from the acquired image to obtain intensity signals corrected for scattered light.