VERFAHREN UND EINRICHTUNG ZUR DECODIERUNG VON BILDSIGNALEN MIT ZUSATZINFORMATIONEN

摘要

The letterbox process is considered in order to introduce a 16:9 large screen format compatible with existing television standards. The 4:3 receivers represent the 16:9 image information in a compatible manner with black stripes at the top and bottom edges of the image. In order to fill out the screen of a 16:9 receiver, additional information that allows an image with an improved quality to be obtained is transmitted in the black stripes of the compatible 4:3 transmission. In order to record PALplus signals on SVHS recorders, the additional information may be partially decoded. For that purpose, the additional information is demodulated before being recorded and is then recorded as basis band signals. Before being reproduced by a 16:9 receiver, the recorded additional information may go backwards through the decoding process carried out before recording, i.e. may be coded into an image signal containing additional information. In 16:9 television receivers, the additional information is then decoded again. Besides the disadvantage that represents the signal recoding effort in the recorder, the cascade coding/decoding worsens the signal-to-noise ratio in the signal. According to the invention, image signals containing partially decoded additional information recorded on SVHS recorders are directly supplied for further decoding to the 16:9 receiver and are not subjected to the corresponding partial decoding in the 16:9 receiver.