Record carrier with watermark

摘要

The invention relates to a record carrier (1) comprising a pattern of substantially parallel tracks (2) for storing data in the form of marks, in which the data is encoded by means of a channel code. The record carrier further includes a watermark (3) which is provided by controlling the parameter of the channel code so as to introduce a predetermined run length distribution in the marks on the record carrier. Brightness differences are caused by introducing this run length distribution. The invention also relates to a device for reading a record carrier, a method of providing a watermark on the record carrier, and a device for providing a watermark on a record carrier.