Watermark embedding

• US 20020150247A1
• Filed: 04/09/2002
• Published: 10/17/2002
• Est. Priority Date: 04/12/2001
• Status: Abandoned Application

• Current Assignee: Civolution BV (Kudelski SA)
• Original Assignee: Civolution BV (Kudelski SA)
• Inventors: Linnartz, Johan Paul Marie Gerard, Talstra, Johan Cornelis
• Application Number:
  US10/118,877
• Publication Number:
  US 20020150247A1
• Time in Patent Office: Days
• US Class Current: 380/205
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: H04N 19/40 using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream
• CPC Class Codes: H04N 19/467 characterised by the embedded information being invisible, e.g. watermarking
• CPC Class Codes: H04N 21/23892 involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• CPC Class Codes: H04N 21/8358 involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467

Abstract

The invention relates to a watermark embedding method and to transcoding and digital recording apparatus including a facility for watermark embedding. A first embodiment incorporates a watermark embedding system with a cascaded decoder/encoder transcoder of the type commonly found in digital recording apparatuses. An input data stream in a first format is received by a decoder (10) of the transcoder. Coding parameters are fed from a first output of the decoder (10) to a first input of an encoder (30) of the transcoder. A second output of the decoder (10) comprises a baseband video signal which is passed to a first input of an adder (24). An output of a watermark generator (22) is fed to a second input of the adder (24). An output of the adder (24) is fed to a second input of the encoder 30. The output of the encoder (30) comprises the information to be recorded in a second format which is compatible with a storage medium.

Claims

1. An apparatus comprising:

a transcoder for converting an input data stream containing information in a first format into a second format; and

a watermark embedding device for embedding a watermark within an output data stream, the apparatus being characterised in that the watermark embedding device is arranged to receive first data from a first part of the transcoder and to provide watermarked data to a second part of the transcoder.

2. The apparatus of claim 1, wherein the first part of the transcoder comprises decoding means for at least partially decoding the input data stream containing information in the first format.

3. The apparatus of claim 1, wherein the second part of the transcoder comprises encoding means for converting to the second format.

4. The apparatus of claim 1, wherein the transcoder comprises a cascaded decoder and encoder.

5. The apparatus of claim 1, wherein the transcoder comprises a motion compensated bit rate transcoder.

6. The apparatus of claim 1, wherein the transcoder comprises a discrete cosine transform coefficient requantization bit rate transcoder.

7. The apparatus of claim 1, wherein the transcoder comprises a discrete cosine transform coefficient damping bit rate transcoder.

8. The apparatus of claim 1, wherein the second format is a format compatible with a storage medium on which the information is to be stored.

9. The apparatus of claim 1, wherein the first and second formats are identical, apart from having different compression characteristics.

10. The apparatus of claim 1, wherein coding parameters from the input data stream are utilised to adapt the watermark to the content in which it is to be embedded.

11. Digital recording apparatus comprising the apparatus of claim 1 and means for recording the output data stream on a storage medium.

12. A method of embedding a watermark within information of a received data stream, the method comprising:

receiving an input data stream containing information in a first format and decoding data from said first format to provide decoded data;

embedding the watermark into the decoded data to provide decoded watermarked data; and

encoding the decoded watermarked data into a second format.