RU2000132222A - METHOD AND DEVICE FOR SELECTIVE PROCESSING OF BLOCKS - Google Patents

Claims (21)

1. A device (150) for detecting a watermark in a watermarked data stream, where the data stream includes a plurality of data elements, each element has at least one characteristic associated with it, a watermark is embedded in selected blocks of the data stream, which satisfy a texture criterion measuring the change in a selected characteristic associated with each data stream data element, the device comprising means (160) for buffering and dividing the watermark data stream by at least one block k, means (170) for selecting watermarked data stream blocks based on a texture criterion substantially similar to the texture criterion used when selecting blocks for embedding a watermark, and means (180) for detecting a watermark only in blocks selected by means selection to reduce the time and number of operations required to process a given number of blocks.  2. The device according to claim 1, wherein the selection tool evaluates the texture criterion in the spatial domain.  3. The device according to claim 1, wherein the texture criterion used in the detection device is identical to the texture criterion used when embedding the watermark.  4. The device according to claim 1, wherein the selection tool is such a selection tool that is used to select blocks in which watermarks are embedded during the implementation process.  5. The device according to claim 1, further comprising a device (110) for initializing the embedding of the watermark in the original data stream and including second means (115) for buffering and dividing the original data stream into many blocks and third means (120) for selecting blocks of the original data stream that satisfy said essentially similar texture criterion, characterized by means (130, 140) for watermarking only selected blocks that satisfy said essentially similar text criterion Ry.  6. The device according to claim 5, in which each second means (115) for buffering and dividing and the third means (120) for selection provides blocks for the means of introduction, and the means of implementation is made with the possibility of selective locking and unlocking based on the output signal of the third means for a choice.  7. The device according to claim 5, in which the second means (115) for buffering and dividing is connected to the first input of the logic device (140) and to the input of the third means (120) for selecting blocks, where the third means for selecting blocks is connected to the implementation means , the output of which is connected to the second input of the logical device, the third means for selecting blocks controls the operation of the logical device in order to trigger selective output by the said logical device of blocks with and without watermarks.  8. The device according to claim 7, in which the logical device includes a multiplexer (140).  9. The device according to claim 5, in which the third means (120) for selecting displays the value of the texture to the embedder, where the embedder modulates the intensity of the watermark depending on the value of the texture value.  10. A method for detecting a watermark embedded in selected watermark data stream blocks that satisfy a texture criterion that measures a change in a selected characteristic associated with each watermark data stream data element, which consists in sharing data data with watermark characters for many blocks with the same size, select only blocks that satisfy the texture criterion essentially similar to that used when choosing blocks for embedding a watermark, and coexist only in the watermark blocks, selected in the selecting step to reduce the time and number of operations required to process a given number of blocks.  11. The method according to claim 10, in which the detection includes calculating the average amplitude of the respective data elements in the selected blocks in the spatial domain with respect to the relatively uncorrelated data stream.  12. The method of claim 10, wherein the data stream is a video stream.  13. The method according to p. 12, which further prevents the reproduction of the video stream when a watermark is not detected.  14. The method of claim 10, wherein the detection texture criterion used when selecting the blocks is identical to the criterion used when embedding the watermark.  15. The method of claim 10, further comprising the steps of initially embedding the watermark in the original data stream, buffering and dividing the original data stream into multiple blocks, and checking the blocks of the original data stream to determine whether they satisfy the aforementioned substantially similar texture criterion , embed a watermark only in the selected blocks, which satisfy the mentioned essentially similar criterion of texture.  16. The method according to p. 15, in which the check is characterized by subtracting the maximum value of the selected characteristics of the texture criterion from the minimum value of the selected characteristics of the texture criterion, and the absolute value of the result is compared with this threshold value.  17. The method according to p. 15, in which the check is characterized by generating the sum of the absolute values of the differences of the selected characteristics of the texture criterion, where the sum of the differences is compared with a given threshold value.  18. The method of claim 17, wherein the data elements are image elements and difference determination actions are performed on pairs of image elements having a separation, arrangement, and / or picture that represents frequencies that better mask the watermark.  19. The method according to p. 15, in which the weakening of changes in the selected characteristics along the edges of each block relative to changes in the selected characteristic within each block.  20. The method of claim 19, wherein the attenuation is characterized by assigning a weight coefficient to each data element within each block, where a lower coefficient is assigned to the data element along the edges of each block than the data elements within each block.  21. The method according to p. 10, in which further only those blocks are selected that are suitable for including a watermark using the same texture criterion that was used in the process of embedding the watermark, and the selected blocks are accumulated in the spatial domain to enhance the watermark, if present, with respect to the relatively uncorrelated data stream.