Videosignalverarbeitung für elektronisches Wasserzeichensetzen

摘要

An image or sequence of images is watermarked without limiting the watermark signal. The watermarking apparatus includes a conventional DCT unit (108) and quantizer (110) for generating an array of quantized DCT coefficients. The array is watermarked (118) by masking the array to select certain ones of the DCT coefficients that are then replaced by zero values to form a masked array. The masked array is further processed by a watermark inserter(120) that replaces the zero valued coefficients with predefined watermark coefficients to form a watermarked array of DCT coefficients, e.g., a watermarked image. A decoder for decoding the bitstream thusly generated and for removing the embedded watermark is also taught. <IMAGE>