Embedding video watermarks without visible impairments
Methods, devices, and computer-program products are provided for adding and decoding data to a digital video signal in a visually imperceptible manner. For example, an encoded video frame can be obtained, and one or more blocks of the encoded video frame can be decoded. Binary data can be added to a subset of pixels from a set of pixels of the one or more blocks. For instance, a pixel component can be modulated to add the binary data. The one or more blocks can be re-encoded using at least one coding mode. The re-encoded one or more blocks can be added to the encoded video frame.
1. A method of processing video data, comprising: obtaining an encoded video frame; determining one or more blocks of the encoded video frame, the one or more blocks including a set of pixels; decoding the one or more blocks of the encoded video frame; modifying the decoded one or more blocks, wherein modifying the decoded one or more blocks includes adding binary data to a subset of pixels of the set of pixels of the one or more blocks at least in part by modulating at least one color-difference component of a pixel of the subset of pixels, the at least one modulated color-difference component representing at least one binary value; re-encoding the modified one or more blocks using at least one coding mode; and replacing the one or more blocks of the encoded video frame with the re-encoded modified one or more block.
2. The method of claim 1 , wherein the one or more blocks include a top row of blocks of the encoded video frame.
3. The method of claim 1 , wherein the subset of pixels of the one or more blocks include at least a top row of pixels of the one or more blocks.
4. The method of claim 1 , wherein the subset of pixels of the one or more blocks include a top two rows of pixels of the one or more blocks.
5. The method of claim 1 , wherein the at least one color-difference component includes at least one of a chroma-blue color-difference component or a chroma-red color-difference component.
6. The method of claim 1 , wherein a luma component of the pixel is not modulated.
7. The method of claim 1 , further comprising:
modifying a subsampling format of the decoded one or more blocks to increase an amount of chrominance information in the decoded one or more blocks.
8. The method of claim 7 , wherein the subsampling format is modified from a 4:2:0 subsampling format to a 4:2:2 subsampling format.
9. The method of claim 1 , wherein re-encoding the one or more blocks using at least one coding mode includes:
defining a first coding mode for a top portion of the one or more blocks;
defining a second coding mode for a bottom portion of the one or more blocks;
re-encoding the top portion of the one or more blocks using the first coding mode; and
re-encoding the bottom portion of the one or more blocks using the second coding mode.
10. An apparatus, comprising: one or more processors; and a non-transitory machine-readable storage medium containing instructions, which when executed on the one or more processors, cause the one or more processors to perform operations including: obtaining an encoded video frame; determining one or more blocks of the encoded video frame, the one or more blocks including a set of pixels; decoding the one or more blocks of the encoded video frame; modifying the decoded one or more blocks, wherein modifying the decoded one or more blocks includes adding binary data to a subset of pixels of the set of pixels of the one or more blocks at least in part by modulating at least one color-difference component of a pixel of the subset of pixels, the at least one modulated color-difference component representing at least one binary value; re-encoding the modified one or more blocks using at least one coding mode; and replacing the one or more blocks of the encoded video frame with the re-encoded modified one or more blocks.
11. The apparatus of claim 10 , wherein the one or more blocks include a top row of blocks of the encoded video frame.
12. The apparatus of claim 10 , wherein the subset of pixels of the one or more blocks includes at least a top row of pixels of the one or more blocks.
13. The apparatus of claim 10 , wherein the at least one color-difference component includes at least one of a chroma-blue color-difference component or a chroma-red color-difference component.
14. The apparatus of claim 10 , wherein a luma component of the pixel is not modulated.
15. The apparatus of claim 10 , further comprising:
modifying a subsampling format of the decoded one or more blocks to increase an amount of chrominance information in the decoded one or more blocks.
16. The apparatus of claim 10 , wherein re-encoding the one or more blocks using at least one coding mode includes:
defining a first coding mode for a top portion of the one or more blocks;
defining a second coding mode for a bottom portion of the one or more blocks;
re-encoding the top portion of the one or more blocks using the first coding mode; and
re-encoding the bottom portion of the one or more blocks using the second coding mode.
17. The apparatus of claim 10 , wherein the apparatus comprises a display device.
18. A non-transitory computer-readable medium having stored thereon instructions that, when executed by one or more processors, cause the one or more processors to: obtaining an encoded video frame; determining one or more blocks of the encoded video frame, the one or more blocks including a set of pixels; decoding the one or more blocks of the encoded video frame; modifying the decoded one or more blocks, wherein modifying the decoded one or more blocks includes adding binary data to a subset of pixels of the set of pixels of the one or more blocks at least in part by modulating at least one color-difference component of a pixel of the subset of pixels, the at least one modulated color-difference component representing at least one binary value; re-encoding the modified one or more blocks using at least one coding mode; and replacing the one or more blocks of the encoded video frame with the re-encoded modified one or more blocks.