Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
  • H04N1/32—Circuits or arrangements for control or supervision between transmitter and receiver or between image input and image output device, e.g. between a still-image camera and its memory or between a still-image camera and a printer device
  • H04N1/32101—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title
  • H04N1/32144—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
  • H04N1/32149—Methods relating to embedding, encoding, decoding, detection or retrieval operations
  • H04N1/32154—Transform domain methods
  • H04N1/32187—Transform domain methods with selective or adaptive application of the additional information, e.g. in selected frequency coefficients
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T1/00—General purpose image data processing
  • G06T1/0021—Image watermarking
  • G06T1/0028—Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
  • G06T1/0035—Output size adaptive watermarking
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
  • H04N1/32—Circuits or arrangements for control or supervision between transmitter and receiver or between image input and image output device, e.g. between a still-image camera and its memory or between a still-image camera and a printer device
  • H04N1/32101—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title
  • H04N1/32144—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
  • H04N1/32149—Methods relating to embedding, encoding, decoding, detection or retrieval operations
  • H04N1/32154—Transform domain methods
  • H04N1/32165—Transform domain methods using cosine transforms
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
  • H04N1/32—Circuits or arrangements for control or supervision between transmitter and receiver or between image input and image output device, e.g. between a still-image camera and its memory or between a still-image camera and a printer device
  • H04N1/32101—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title
  • H04N1/32144—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
  • H04N1/32149—Methods relating to embedding, encoding, decoding, detection or retrieval operations
  • H04N1/32267—Methods relating to embedding, encoding, decoding, detection or retrieval operations combined with processing of the image
  • H04N1/32277—Compression
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
  • H04N19/46—Embedding additional information in the video signal during the compression process
  • H04N19/467—Embedding additional information in the video signal during the compression process characterised by the embedded information being invisible, e.g. watermarking
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
  • H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
  • H04N21/238—Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth; Processing of multiplex streams
  • H04N21/2383—Channel coding or modulation of digital bit-stream, e.g. QPSK modulation
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
  • H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
  • H04N21/238—Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth; Processing of multiplex streams
  • H04N21/2389—Multiplex stream processing, e.g. multiplex stream encrypting
  • H04N21/23892—Multiplex stream processing, e.g. multiplex stream encrypting involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
  • H04N21/43—Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
  • H04N21/434—Disassembling of a multiplex stream, e.g. demultiplexing audio and video streams, extraction of additional data from a video stream; Remultiplexing of multiplex streams; Extraction or processing of SI; Disassembling of packetised elementary stream
  • H04N21/4348—Demultiplexing of additional data and video streams
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/80—Generation or processing of content or additional data by content creator independently of the distribution process; Content per se
  • H04N21/83—Generation or processing of protective or descriptive data associated with content; Content structuring
  • H04N21/835—Generation of protective data, e.g. certificates
  • H04N21/8358—Generation of protective data, e.g. certificates involving watermark
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N2201/00—Indexing scheme relating to scanning, transmission or reproduction of documents or the like, and to details thereof
  • H04N2201/32—Circuits or arrangements for control or supervision between transmitter and receiver or between image input and image output device, e.g. between a still-image camera and its memory or between a still-image camera and a printer device
  • H04N2201/3201—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title
  • H04N2201/3225—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title of data relating to an image, a page or a document
  • H04N2201/3233—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title of data relating to an image, a page or a document of authentication information, e.g. digital signature, watermark
  • H04N2201/324—Selecting a particular authentication information from amongst a plurality of different authentication information

Definitions

• Distribution of digital content for media streams is subject to several problems.
• One problem is that it is easy to make exact copies of digital content, thus allowing any recipient of that content to redistribute it, whether or not authorized to do so.
• One aspect of the invention is a method of embedding information in a media stream.
• the method includes (1) selecting a set of locations within that media stream to embed information, (2) selecting a set of possible alterations to make at those locations, and (3) making a subset of the possible alterations.
• the set of locations and possible alterations is herein sometimes called a "watermark.”
• the subset of actual alterations that are made is herein sometimes called a "fingerprint.”
• the method includes determining a set of intra-coded blocks in an MPEG-2 encoding of the digital content for that media stream.
• Each intra-coded block has a set of run-level encoded values for DCT coefficients for that block.
• the method determines if there is an alternative set of values which differ only a little from the original set of values, and which do not change the bit-length of the encoded block.
• Each such block thus provides both a location to embed information, and an alteration for that location, and thus provides at least one bit worth of embeddable information.
• macroblocks may be used instead of blocks.
• the invention is not restricted to movies, but is also applicable to other digital content and other media streams, such as for example animation or sound, as well as to still media, such as for example pictures or illustrations, and to databases and other collections of information.
• Figure 2 illustrates MPEG encoding and generation of alt-blocks according to the invention.
• Figure 5 shows a flow diagram of a recursive technique that can be used to identify possible alterations in a block for determining alt-blocks according to the invention.
• Figure 6 shows a flow diagram of a method for detecting a fingerprint that embeds information in digital content.
• digital content describes data in a digital format, intended to represent media streams or other information for presentation to an end viewer.
• Digital content is distinguished from packaging information, such as for example message header information.
• decoding describes generating data in a form for presentation of the media stream, in response to the digital content for the media stream in an encoded format.
• the encoded format might include an industry standard encoded format such as MPEG-2.
• the concept of decoding as described herein is sufficiently general to include other encoding formats for the media stream.
• presentation describes generating information in a form for viewing (or other sensing) of the media stream, such as for example audio and visual information for viewing a movie.
• presentation of a movie might include visual display of the frames or fields of motion picture, as well as audio presentation of a soundtrack associated with that motion picture.
• presentation as described herein is sufficiently general to include a wide variety of other forms of generating information for reception by end viewers, including audio, visual, or otherwise.
• original movie and “alt-movie” describe alternative versions of the same media stream, such as one being an original version of that media stream introduced into a system using aspects of the invention, and another being an alternative version of that same media stream generated in response to the original movie.
• original block and “alt-block” describe alternative versions of the same individual block or macroblock within the original movie or alt-movie.
• a difference between the original movie and the alt-movie is historical, in that the alt-movie can be substituted for the original movie in every respect.
• a difference between any one original block and its associated alt-block is historical, in that the alt-block can be substituted for the original block in every respect.
• the System 100 includes video distribution network 110.
• the video distribution network includes at least one injection origin 120 and a plurality of end viewer premises 130.
• video distribution network 110 includes a redundant communication network, such as the Internet or a secure subnet thereof.
• a redundant communication network such as the Internet or a secure subnet thereof.
• video distribution network 110 there is no particular requirement for video distribution network 110 to use any particular communication technique.
• any communication technique capable of delivering copies of digital content 121 from injection origin 120, through video distribution network 110, and ultimately to end viewer premises 130, would also be suitable.
• Distribution of digital content 121 using video distribution network 110 in a preferred embodiment provides that copies of digital content 121 might be recorded and maintained at multiple caching devices 111, and might be delivered using more than one pathway from injection origin 120 to end viewer premises 130.
• any sender delivers digital content 121 to any recipient within the video distribution network 110
• the sender performs adaptation of the digital content 121 for that recipient.
• the sender decrypts its copy of the digital content, embeds information in the media stream represented by that digital content by partially fingerprinting that digital content, and re-encrypts that partially fingerprinted digital content.
• the method of finge ⁇ rinting provides for detecting individual viewers anyway.
• individual end viewer premises 130 receives the encrypted, finge ⁇ rinted digital content 121, it records that digital content 121 in local video library 131.
• Local video library 131 maintains digital content 121 in its encrypted, finge ⁇ rinted form for later distribution to one or more playback elements 132.
• local video library 131 distributes digital content 121 to one or more playback elements 132, at which digital content 121 is substantially simultaneously decrypted and presented to end viewers for viewing.
• Figure 2 illustrates MPEG encoding and generation of alternative blocks (i.e., alt-blocks) according to the invention.
• the invention is not limited to use with MPEG encoded digital content.
• frame 200 of digital content is processed according to the MPEG standard.
• this frame is shown as an image frame in RGB, CMYK, or some other format.
• the invention is also applicable to other types of digital content.
• the data in the frame itself can be processed. If the data in the frame itself is processed, the frame is said to be "intra coded.”
• the difference of the data from data predicted for the frame can be processed.
• Prediction of frame data can be based on data in a previous frame or on data in both previous and succeeding frames.
• the frame is said to be a "predictive" frame; in the latter case, the frame is said to be a "bidirectional" frame.
• each chrominance macroblock contains four 8x8 blocks
• each chrominance macroblock contains eight 8x8 blocks.
• each block of luminance and chrominance data is processed.
• a discrete cosine transform (DCT) is applied to the block, resulting in a set of 8x8 DCT coefficients 230.
• the DCT coefficients are then quantized. Quantization involves dividing all of the DCT coefficients for a block by an integer and discarding any remainders. The process results in a few non-zero coefficients interspersed among coefficients of zero. The integer by which the coefficients are divided is the quantization level for the block. Quantization results in some loss of precision; however, depending on the degree of quantization permitted, the loss of precision will be acceptable to an end viewer (if noticed at all). The benefit of quantization is that it allows for a high degree of data compression.
• the quantized data for a block is then ordered by running through the block in a zig-zag pattern such as pattern 240. This ordering results in a series of non-zero coefficients, called levels, separated by runs of zeros. In Figure 2, such a series is shown representationally at reference numeral 250.
• the series of levels and zeros are converted into a list of pairs of numbers through a process called run level encoding.
• the pairs of numbers in the list are called run level codes, represented at reference number 260.
• the first number in each pair represents a number of zeros in a run preceding a level, and the second number in each pair represents the level.
• the series of levels and zeros (A 0 0 0 0 0 B 0 0 ...) can be converted to the pairs (0,A) and (5,B), etc., with A and B being values for levels.
• VLCs variable length codes
• VLCs 270 include four dashes representing four variable length codes, which in turn represent four run level codes for quantized DCT coefficients for a single 8x8 pixel block of luminance or chrominance data.
• a block could be represented by fewer or more such VLCs of shorter or longer length.
• the conversion of a frame into VLCs involves downsampling and quantization; as a result, the VLCs do not represent the exact frame data.
• the invention takes advantage of this fact by determining one or more alternate sets of VLCs for a frame that represent the frame in almost, but not exactly, the same way. These alternate sets of VLCs form alt-blocks according to the invention.
• the original set of VLCs is referred to as the original block.
• the total length of the VLCs for an alt- block should be equal to the total length of the VLCs for the original block. This is shown representationally in Figure 2, where the total lengths of the VLCs for alt-blocks 280 are equal to the total length of VLCs 270 for original block 290.
• FIG. 3 illustrates preservation of packetization according to the invention.
• data stream 300 includes original blocks 310 of VLCs along with control data and the like in headers 320.
• the variable number and lengths of VLCs in each block are represented by the dashed lines in blocks 310.
• Data stream 300 is packetized for presentation as a media stream as packetized data stream 330.
• the packetized data stream includes its own packet headers 340 and packets 350 including all data from data stream 300.
• the packet boundaries can occur at any place in data stream 300, as shown in Figure 3 by vertical lines between packetized data stream 330 and data stream 300. Thus, the packet boundaries can occur in blocks 310 and headers 320.
• Data stream 360 includes alt-blocks 370 for some of the blocks in data stream 300. These alt-blocks can be inserted into the data stream in place of the corresponding original blocks in order to embed data in the data stream.
• the total length of the VLCs for an alt-block equals the total length of the VLCs for the corresponding original block.
• the number, size, or both of the individual VLCs can vary from those in the original blocks, as long as the overall block lengths are unchanged. These variations are represented by the dashed lines in blocks 370.
• an alt-block can be substituted into packetized data stream 330 by substituting a packet with the alt-block for the packet with the original block.
• the preferred embodiment of the invention excludes blocks which span packet boundaries from the possible locations for embedding data. In other words, alt-blocks preferably are not permitted for blocks that span packet boundaries in the packetized data stream.
• FIG. 4 shows a flow diagram of a method for watermarking and fmge ⁇ rinting digital content with a set of locations at which information might be embedded.
• a set of block locations and alt-blocks at those locations are a specific example of a set of locations and possible alterations in the context of MPEG.
• a set of such locations and possible alterations at those locations forms a watermark according to the invention.
• Step 401 and 402 are the steps for creating this watermark. Preferably, these steps are performed at injection origin 120.
• step 401 locations for embedding information are selected in digital content.
• this digital content can be an MPEG-1, MPEG-2, or MPEG-4 (collectively referred to as simply MPEG hereinafter) encoded digital movie.
• MPEG-1 MPEG-1
• MPEG-2 MPEG-2
• MPEG-4 collectively referred to as simply MPEG hereinafter
• the following steps are described in the context of an encoded digital movie. However, the invention is equally applicable to other digital content, and application of these steps would not require further invention or undue experimentation.
• the locations are preferably 8x8 blocks of either luminance and chrominance DCT coefficients, but could also be 16x16 macroblocks of such coefficients.
• the locations are blocks of intra coded macroblocks, although the invention can also be used with locations that are complete intra coded macroblocks. Blocks and intra coded macroblocks are well known in the art of MPEG encoding.
• the invention also can be applied to other blocks that contain coefficients from transforms other than DCT, for example wavelets or any other transform in which luminance or chrominance information is presented in some transformed domain (e.g., in a non-MPEG encoding scheme), or to transforms of RGB data, CMYK data, YUV data, and more generally, to any transform in which information useful for presentation of the media stream is represented in the digital content.
• transforms other than DCT for example wavelets or any other transform in which luminance or chrominance information is presented in some transformed domain (e.g., in a non-MPEG encoding scheme), or to transforms of RGB data, CMYK data, YUV data, and more generally, to any transform in which information useful for presentation of the media stream is represented in the digital content.
• transforms other than DCT for example wavelets or any other transform in which luminance or chrominance information is presented in some transformed domain (e.g., in a non-MPEG encoding scheme), or to transforms of
• step 401 preferably occurs in conjunction with step 402.
• step 402 possible alterations to the block are selected.
• these alterations preferably do not involve any change to the length of the digital content at the locations (i.e., blocks) where information is embedded.
• each block has a set of run-level encoded values for discrete cosine transform (DCT) coefficients for that block.
• DCT discrete cosine transform
• the invention determines if there is an alternative set of values which differ only a little from the original set of values, and which do not change the bit-length of the encoded block.
• Each such block thus provides both a location to embed information and an alteration for that location, and thus provides at least one bit worth of embeddable information.
• macroblocks are used instead of blocks.
• VLCs variable length codes
• run level codes that represent discrete cosine transforms of pixel data values.
• Huffman codes that provide an extremely efficient way to compress data.
• the resulting data for different blocks can be different lengths.
• any changes to the VLCs for the block must result in a net length difference of zero. This can be accomplished in several ways.
• one VLC could be substituted for another VLC that has the same length.
• more than one VLC could be substituted for an equal number of VLCs, with the sums of the lengths of the original and substituted VLCs being equal. For example, two VLCs with length 5 and 6 could be substituted for VLCs with lengths 4 and 7.
• one or more VLCs could be added or deleted. In order to reduce visible impact, additions and deletions preferably are restricted to VLCs with a level of one. Combinations of these three techniques, as well as other techniques, can be utilized.
• alt-blocks preferably are limited to blocks resulting from two changes to VLCs.
• changes to the data at the identified locations preferably are increases or decreases by a value of one level in the run level codes.
• MPEG involves quantization of data represented by the run level codes. If the quantization scale (QS) is higher than 24, even a level change of one can result in unacceptable distortion of the presentation. Thus, only blocks with a quantization scale of less than or equal to 24 preferably are used to form alt-blocks.
• the block includes one or two run level codes that can be changed by a value of plus or minus one level, with the change(s) in run level(s) resulting in VLC(s) that have a same length as the VLC(s) for the unchanged levels (if two run level codes are changed, only the sums of the lengths of the VLCs need to be equal)
• an initial process is started that in turn calls another instance of itself.
• the called instances of the process can then also call other instances of the process, etc.
• the recursive call is shown as a dashed line.
• the initial process makes a first permissible modification of a VLC for a block in step 501.
• a modification of a VLC is permissible if it meets the criteria for quantization level and any other requirements established for modifications to VLCs.
• the process checks to see if the net change in length of the modified VLCs for the block is zero. If the net change (including changes from modifications in any calling recursive processes) is zero, a possible alt-block has been found. The possible alt-block is added to a list of possible alt- blocks in step 503. If the net change is not zero, the change is noted in step 504.
• the process recursively calls another instance of itself in step 507, passing on the net change up to that point.
• the recursively called process starts from the next possible modification of a VLC for the block.
• This next modification might be another modification of the first or current VLC or a modification of the next VLC.
• the processes continue to make recursive calls until the end of the block is reached.
• flow for that process is diverted by step 505 to step 506, where the recursive process returns.
• the process that called the returning process continues at step 508, where a next permissible modification of the VLCs in the block is made. This entire recursive process continues until the initial process reaches the end of the block.
• the recursive technique of Figure 5 can be used to find all possible alt-blocks for a given block. However, in alternative embodiments, the technique could be stopped once a certain number of possible alt-blocks have been found, or even once a single alt-block has been found. If more than one possible alt-block has been found, one or more alt-blocks could be selected from the possible alt-blocks, for example pseudorandomly. Other variations are possible and remain within the scope of the invention.
• finge ⁇ rinting is performed in step 403. Finge ⁇ rinting is the process of actually making some of the alterations at the selected locations in order to embed information in the digital content. In the MPEG context, alterations are made by using alt- blocks in place of some original blocks.
• alt-block can be used to embed one bit at that location. For example, once the set of locations and possible alterations are defined, a "0" can be embedded at a location by using an original block at that location, and a "1" can be embedded by using an alt-block at the location. Other schemes for embedding the data also can be used. Furthermore, if more than one alt-block is found for a block at a selected location, those alt- blocks can be used to embed more than one bit at that location. For example, the original block could represent "00,” a first alt-block could represent "01,” a second alt-block could represent "10,” and a third alt-block could represent "11.” Again, other schemes for using multiple alt-blocks are possible.
• step 403 information (i.e., bits) are embedded in the digital content by substituting alt- blocks for original blocks at some of the selected locations in the digital content.
• information i.e., bits
• only a subset of the locations are subject to change at each of plural different points in distribution of the digital content.
• a first subset can be subject to change at primary caches 112
• a second subset can be subject to change at intermediate caches 113
• a third subset can be subject to change at leaf caches 114, etc.
• not all of the locations in each subset will be altered because at least some "0s" (or other values depending on the coding scheme) will be embedded at the available locations.
• Figure 6 shows a flow diagram of a method for extracting embedded information from a finge ⁇ rint in digital content.
• the data can be extracted at computing device that can perform the steps shown in Figure 6.
• Such a computing device preferably includes at least a processor and a memory for storing the digital content and for storing instructions for performing the steps.
• the identifying information preferably is itself embedded in the digital content in some robust fashion or is self-evident from the digital content.
• the identifying information could be the title of the movie, which would be self-evident from the content of the movie.
• Other identifying information can be utilized.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Computer Security & Cryptography (AREA)
• Compression Or Coding Systems Of Tv Signals (AREA)
• Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)
• Editing Of Facsimile Originals (AREA)
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