Method for processing picture information having a large dynamic range with a television camera tube, and also a device for applying the method

摘要

The blooming effect in pictures of a television camera tube (such as a vidicon, an orthicon or an isocon) is counteracted by setting the cathode potential to a first standard value during one scan of the scanning electron beam and to a second value during a number of subsequent scans of the scanning electron beam. During the one scan picture information is obtained both about bright and dark parts of the picture. During the subsequent scans only picture information is obtained from relatively bright parts of the picture.The videosignals of different scannings are stored and combined. The resulting combined videosignal comprises picture information about bright or dark parts of the image that otherwise would have been lost.