Patent ID: 6996248

Claim:
An apparatus for applying data representing a watermark to data representing an image, the apparatus comprising: a source of location and time data; an error coding unit connected to receive the location and time data for applying a forward error correction algorithm to the said location and time data and outputting error coded data therefrom; a code spreading unit coupled to receive the error coded data for spreading the error coded data to create spread data by repeatedly outputting portions of the error coded data a number of times therefrom; a DES code generator for generating and outputting data representing a DES code; a combiner for combining the spread data and the DES code and outputting watermark data representing a location and time specific watermark; a receiver for receiving signals containing said data representing an image as DCT coefficients in transform space, which data is received in an encoded and compressed form on a signal medium, and for receiving an apparatus specific key; a decoding circuit responsive to the apparatus specific key for decoding and decompressing the received signals to recover the data representing an image therefrom; a control circuit for analyzing at least a component of the image data to determine an attribute thereof and to output a signal representative of the attribute; a marking control unit, coupled to receive the signal from the control circuit, the image data from the source and the watermark data from the combiner, for adding the watermark data to the image data depending on a characteristic of the attribute and a characteristic of the image data; an inverse DCT transform circuit connected to receive the watermarked image data and to convert the same from data representing the image as DCT coefficients in transformation space to data representing the image in pixel space; a pixel processor connected to receive the data representing the image in pixel space for converting the pixel data into a format suitable for display; and a projector connected to receive formatted pixel data from the pixel processor for projecting the image represented thereby.