JP2010272920A - Electronic watermark embedding apparatus, electronic watermark embedding method, and electronic watermark embedding program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently arrange electronic watermark for every pages in an electronic document consisting of a plurality of pages. <P>SOLUTION: In an electronic watermark embedding apparatus 200, a data input part 201 extracts data of an i-th page from the electronic document 140 consisting of n pages, and writes the data themselves, or hash values or the like of the data as data for embedding X(i) (i=1, 2, ..., n) in a storage device 122. If an electronic watermark embedding part 202 reads out the data for embedding X(i) from the storage device 122, it divides the read out data for embedding X(i) to create m pieces of divided data W(i, j) (j=1, 2, ..., m). The electronic watermark embedding part 202 embeds the created m pieces of the divided data W(i, j) in j-th page as the electronic watermark. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a digital watermark embedding apparatus, a digital watermark embedding method, and a digital watermark embedding program. The present invention particularly relates to a digital watermark generating apparatus for printed matter.

  Some digital watermarks (also simply referred to as “watermarks”) are black (white) when copied or a character string such as “copy prohibited” appears. In addition, there are some that put information in the watermark itself (see, for example, Patent Documents 1 to 3).

JP 2007-81891 A JP 2005-252991 A JP 2004-104494 A

  Although the purpose of inserting a watermark is not limited to one, for example, when tampering detection is performed, it is conceivable to embed the same information as the original information as a watermark. In this case, it is necessary to embed a considerable amount of watermark, but there is a limit to the amount of information that can be embedded as a digital watermark in printed matter. Conventionally, with respect to an electronic document composed of a plurality of pages, for example, a certain page overflows without entering a watermark, and another page has an excess of the watermark area. As described above, the conventional technique has a problem that the watermark cannot be embedded efficiently.

  For example, an object of the present invention is to efficiently arrange a digital watermark for each page of an electronic document including a plurality of pages.

An electronic watermark embedding device according to one aspect of the present invention includes:
An electronic watermark embedding device for embedding an electronic watermark in an electronic document consisting of a plurality of pages,
A data input unit that inputs information corresponding to each page of the plurality of pages and writes the information to a storage device as a plurality of embedding data;
The embedding data of the plurality of embedding data written by the data input unit is read from the storage device, the embedding data read is divided by the processing device to generate a plurality of divided data, and the generated plurality of divided data And an electronic watermark embedding unit that embeds the image as a digital watermark in a distributed manner on the plurality of pages.

  According to one aspect of the present invention, in an electronic watermark embedding apparatus that embeds an electronic watermark in an electronic document consisting of a plurality of pages, the electronic watermark embedding unit divides the embedding data, which is information corresponding to each page, into a plurality The divided data is generated, and the generated divided data is distributed over a plurality of pages and embedded as a digital watermark, whereby the digital watermark can be efficiently arranged for each page. As a result, it is possible to embed a digital watermark with a larger amount of information, suppress deterioration in quality of the electronic document due to the digital watermark, and the like.

1 is a block diagram illustrating a configuration of a printing system according to a first embodiment. 6 is a diagram illustrating an example of a watermark layout according to Embodiment 1. FIG. 2 is a diagram illustrating an example of a hardware configuration of a print server according to Embodiment 1. FIG. 3 is a flowchart illustrating an operation of the digital watermark embedding device according to the first embodiment. 6 is a diagram showing an example of a watermark layout in Embodiment 1. FIG. It is a flowchart which shows an example of the algorithm of step S102 of FIG. 10 is a diagram showing an example of a watermark layout in Embodiment 2. FIG. 10 is a block diagram illustrating a configuration of a printing system according to Embodiment 3. FIG. 10 is a flowchart illustrating an operation of the digital watermark embedding device according to the third embodiment. FIG. 10 is a diagram illustrating an example of a watermark layout in the third embodiment. FIG. 20 is a diagram illustrating an example of a watermark layout in a fourth embodiment. FIG. 10 is a block diagram illustrating a configuration of a printing system according to a fifth embodiment. 10 is a flowchart illustrating an operation of the digital watermark embedding device according to the third embodiment. FIG. 20 is a diagram illustrating an example of a watermark layout in a fifth embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a block diagram illustrating a configuration example of a printing system 100 according to the present embodiment.

  In FIG. 1, the printing system 100 includes a client 110, a print server 120, and a printer 130. The client 110 is, for example, a PC (personal computer). The print server 120 is a server computer, for example, and includes a digital watermark embedding device 200 (spooler). The print server 120 includes hardware such as a processing device 121 and a storage device 122. The hardware is used by each unit of the digital watermark embedding apparatus 200. For example, the processing device 121 is used to perform calculation, processing, reading, writing, and the like of data and information in each unit of the digital watermark embedding device 200. The storage device 122 is used to store the data and information.

  The digital watermark embedding device 200 includes a data input unit 201 and a digital watermark embedding unit 202. The data input unit 201 is provided with an original original page watermark data acquisition function 211. The digital watermark embedding unit 202 is provided with a watermark page data layout function 212 and an original digital watermark merge function 213.

  When a user executes a document printing application on the client 110 side and requests printing of an electronic document 140 composed of a plurality of pages, a spool file 150 is generated on the print server 120 side and stored in the storage device 122. Here, the spool file 150 refers to a file in which an original of the electronic document 140 (an electronic document 140 without a digital watermark embedded) is recorded as print data. In the print server 120, the data input unit 201 of the digital watermark embedding device 200 reads the spool file 150 from the storage device 122 by the original all page watermark data acquisition function 211 and acquires the watermark data of all pages of the electronic document 140. Here, the watermark data of a certain page refers to data in which information corresponding to the page is recorded (not necessarily embedded in the page). Examples include the data (content) of the page itself, data obtained by subjecting the data of the page to a predetermined conversion process (for example, a hash value), data related to the data of the page (for example, a summary of the content), and the like. Can be mentioned. The digital watermark embedding unit 202 of the digital watermark embedding device 200 determines a watermark layout for each page from the watermark data of all pages acquired by the data input unit 201 by the watermark page data layout function 212. Here, the watermark layout of a page means the watermark data of each page (including the page and other pages) embedded in the page and the position where the watermark data of each page is embedded. The digital watermark embedding unit 202 merges the determined watermark layout and the original of the electronic document 140 by the original digital watermark merge function 213. That is, the digital watermark embedding unit 202 embeds a digital watermark in the electronic document 140 according to the determined watermark layout. The print server 120 uses the printer 130 to print the electronic document 140 in which the digital watermark is embedded.

  FIG. 2 is a diagram illustrating an example of a watermark layout.

  In the example of FIG. 2, the digital watermark embedding device 200 divides and embeds the watermark data into each page according to the watermark data amount of each page for each chapter of the electronic document 140. For example, the digital watermark embedding apparatus 200 embeds the watermark data of the first to third pages of the electronic document 140 in a distributed manner on each page of the first to third pages.

  FIG. 3 is a diagram illustrating an example of a hardware configuration of the print server 120.

  In FIG. 3, a print server 120 is a computer, and includes an LCD 901 (Liquid / Crystal / Display), a keyboard 902 (K / B), a mouse 903, an FDD 904 (Flexible / Disk / Drive), and a CDD 905 (Compact / Disc / Drive). Hardware devices. These hardware devices are connected by cables and signal lines. Instead of the LCD 901, a CRT (Cathode / Ray / Tube) or other display device may be used. Instead of the mouse 903, a touch panel, a touch pad, a trackball, a pen tablet, or other pointing devices may be used.

  The print server 120 includes a CPU 911 (Central Processing Unit) that executes a program. The CPU 911 is an example of the processing device 121. The CPU 911 includes a ROM 913 (Read / Only / Memory), a RAM 914 (Random / Access / Memory), a communication board 915, an LCD 901, a keyboard 902, a mouse 903, an FDD 904, a CDD 905, an HDD 920 (Hard / Disk / Drive) via a bus 912. And control these hardware devices. Instead of the HDD 920, a flash memory, an optical disk device, a memory card reader / writer, or other storage medium may be used.

  The RAM 914 is an example of a volatile memory. The ROM 913, the FDD 904, the CDD 905, and the HDD 920 are examples of nonvolatile memories. These are examples of the storage device 122. The communication board 915, the keyboard 902, the mouse 903, the FDD 904, and the CDD 905 are examples of input devices. The communication board 915 and the LCD 901 are examples of output devices.

  The communication board 915 is connected to a LAN (Local / Area / Network) or the like. The communication board 915 is not limited to a LAN, but is an IP-VPN (Internet, Protocol, Private, Network), a wide area LAN, an ATM (Asynchronous / Transfer / Mode) network, or a WAN (Wide / Area / Network) It does not matter if it is connected to. LAN, WAN, and the Internet are examples of networks.

  The HDD 920 stores an operating system 921 (OS), a window system 922, a program group 923, and a file group 924. The programs in the program group 923 are executed by the CPU 911, the operating system 921, and the window system 922. The program group 923 includes programs that execute the functions described as “˜units” in the description of the present embodiment. The program is read and executed by the CPU 911. The file group 924 includes data, information, and signal values described as “˜data”, “˜information”, “˜ID (identifier)”, “˜flag”, and “˜result” in the description of this embodiment. And variable values and parameters are included as items of “˜file”, “˜database”, and “˜table”. The “˜file”, “˜database”, and “˜table” are stored in a storage medium such as the RAM 914 or the HDD 920. Data, information, signal values, variable values, and parameters stored in a storage medium such as the RAM 914 and the HDD 920 are read out to the main memory and the cache memory by the CPU 911 via a read / write circuit, and extracted, searched, referenced, compared, and calculated. It is used for processing (operation) of the CPU 911 such as calculation, control, output, printing and display. During the processing of the CPU 911 such as extraction, search, reference, comparison, calculation, calculation, control, output, printing, and display, data, information, signal values, variable values, and parameters are temporarily stored in the main memory, cache memory, and buffer memory. Remembered.

  The arrows in the block diagrams and flowcharts used in the description of this embodiment mainly indicate input / output of data and signals. Data and signals are recorded in memory such as RAM 914, FDD904 flexible disk (FD), CDD905 compact disk (CD), HDD920 magnetic disk, optical disk, DVD (Digital Versatile Disc), or other recording media Is done. Data and signals are transmitted by a bus 912, a signal line, a cable, or other transmission media.

  In the description of the present embodiment, what is described as “to part” may be “to circuit”, “to device”, “to device”, and “to step”, “to process”, “to”. ~ Procedure "," ~ process ". That is, what is described as “˜unit” may be realized by firmware stored in the ROM 913. Alternatively, what is described as “˜unit” may be realized only by software, or only by hardware such as an element, a device, a board, and wiring. Alternatively, what is described as “to part” may be realized by a combination of software and hardware, or a combination of software, hardware and firmware. Firmware and software are stored as programs in a recording medium such as a flexible disk, a compact disk, a magnetic disk, an optical disk, and a DVD. The program is read by the CPU 911 and executed by the CPU 911. That is, the program causes the computer to function as “to part” described in the description of the present embodiment. Or a program makes a computer perform the procedure and method of "-part" described by description of this Embodiment.

  FIG. 4 is a flowchart showing the operation of the digital watermark embedding apparatus 200 (the digital watermark embedding method according to the present embodiment and the processing procedure of the digital watermark embedding program according to the present embodiment).

  In step S101 (data input processing) of FIG. 4, the data input unit 201 reads the electronic document 140 composed of n (n is an integer satisfying n> 1) pages from the storage device 122, and reads the electronic document 140 of the read electronic document 140. Information corresponding to each page is input and written into the storage device 122 as n embedding data (watermark data). For example, the data input unit 201 extracts the data of the i (i = 1, 2,..., N) th page from the electronic document 140 and embeds the data itself or the hash value of the data. To the storage device 122 as data X (i).

  In step S102 (digital watermark embedding process), the digital watermark embedding unit 202 reads each of the n embedding data written by the data input unit 201 in step S101 from the storage device 122. The digital watermark embedding unit 202 divides the read embedding data by the processing device 121 to generate m (m is an integer where m = n) divided data. The digital watermark embedding unit 202 distributes the generated m pieces of divided data to n pages of the electronic document 140 and embeds them as a digital watermark. For example, when the digital watermark embedding unit 202 reads the embedding data X (i) from the storage device 122, the electronic watermark embedding unit 202 divides the read embedding data X (i) into m pieces of divided data W (i, j) (j = 1, 2, ..., m). Then, the digital watermark embedding unit 202 embeds the generated m pieces of divided data W (i, j) as a digital watermark in the jth page. In the present embodiment, the digital watermark embedding unit 202 divides the data amount of the divided data W (i, j) into the maximum data amount A (j) of the digital watermark that can be embedded in the jth page × embedding data X ( The data amount P (i) of i) is limited to be equal to or less than the total data amount ΣP (i) from the embedded data X (1) to X (n).

  FIG. 5 is a diagram showing an example of a watermark layout in the present embodiment.

In FIG. 5, the watermark data amount is 1K (kilo) bytes for the first page, 1K bytes for the second page, and 500 bytes for the third page. Also, it is assumed that the amount of watermark data that can be embedded is 900 bytes per page (may vary from page to page). That is, in this example, n = m = 3, A (1) = A (2) = A (3) = 900 bytes, P (1) = 1,000 bytes, P (2) = 1,000 bytes , P (3) = 500 bytes and ΣP (i) = 2500 bytes. Therefore, in this example, the data amount of the divided data W (i, j) is limited as follows.
Data amount of divided data W (1,1) ≦ A (1) × P (1) ÷ ΣP (i) = 360 bytes of data amount of divided data W (1,2) ≦ A (2) × P (1) ÷ ΣP (i) = data amount of 360-byte divided data W (1,3) ≦ A (3) × P (1) ÷ ΣP (i) = data amount of 360-byte divided data W (2,1) ≦ A (1) × P (2) ÷ ΣP (i) = 360 byte divided data W (2,2) data amount ≦ A (2) × P (2) ÷ ΣP (i) = 360 byte divided data W (2 , 3) data amount ≦ A (3) × P (2) ÷ ΣP (i) = 360 byte divided data W (3,1) data amount ≦ A (1) × P (3) ÷ ΣP (i) = Data amount of 180-byte divided data W (3,2) ≦ A (2) × P (3) ÷ ΣP (i) = Data amount of 180-byte divided data W (3,3) ≦ A (3) × P (3) ÷ ΣP ( ) = 180 bytes

  The operation of the digital watermark embedding apparatus 200 is as follows.

  First, the data input unit 201 reads all pages and acquires watermark data of all pages. That is, the data input unit 201 acquires the embedding data X (1) to X (3) from the electronic document 140 including three pages and writes it in the storage device 122.

  Next, the digital watermark embedding unit 202 calculates the ratio of the watermark data for each page (with respect to the watermark data of all pages) (40% for the first page, 40% for the second page, and 20% for the third page). Become). The digital watermark embedding unit 202 embeds a watermark by maximizing the ratio of watermark data for each page. The watermark data of the first page is embedded with 360 bytes on the first page of the original, 360 bytes on the second page of the original, and 280 bytes on the third page of the original. In the watermark data of the second page, 360 bytes are embedded in the first page of the original, 360 bytes are embedded in the second page of the original, and 280 bytes are embedded in the third page of the original. The watermark data of the third page is embedded with 180 bytes on the first page of the original, 180 bytes on the second page of the original, and 140 bytes on the third page of the original.

  That is, when the digital watermark embedding unit 202 reads the embedding data X (1) written by the data input unit 201 in step S101 from the storage device 122, the read embedding data X (1) is 360 bytes, 360 bytes. The divided data W (1,1), W (1,2), and W (1,3) are generated by dividing into the remaining three 280 bytes. Then, the digital watermark embedding unit 202 embeds the generated divided data W (1,1), W (1,2), and W (1,3) as digital watermarks in the first to third pages, respectively. Similarly, when the digital watermark embedding unit 202 reads the embedding data X (2) written by the data input unit 201 in step S101 from the storage device 122, the digital embedding data X (2) is 360 bytes, 360 The divided data W (2,1), W (2,2), and W (2,3) are generated by dividing the data into three bytes, that is, the remaining 280 bytes. Then, the digital watermark embedding unit 202 embeds the generated divided data W (2,1), W (2,2), and W (2,3) as digital watermarks in the first to third pages, respectively. Similarly, when the digital watermark embedding unit 202 reads the embedding data X (3) written by the data input unit 201 in step S101 from the storage device 122, the read embedding data X (3) is 180 bytes, 180%. The divided data W (3, 1), W (3, 2), and W (3, 3) are generated by dividing into three bytes, that is, the remaining 140 bytes. Then, the digital watermark embedding unit 202 embeds the generated divided data W (3, 1), W (3, 2), and W (3, 3) as digital watermarks in the first to third pages, respectively.

  In this example, the distribution pattern of the digital watermark is such that the digital watermark is embedded in order from the smallest page number, but other distribution patterns may be employed. For example, the digital watermark embedding unit 202 is for embedding so that the data amounts of the divided data W (1,1), W (1,2), and W (1,3) are 280 bytes, 360 bytes, and 360 bytes, respectively. The data X (1) may be divided, and the data amounts of the divided data W (1,1), W (1,2), and W (1,3) are 350 bytes, 325 bytes, and 325 bytes, respectively. As described above, the embedding data X (1) may be divided.

  FIG. 6 is a flowchart showing an example of the algorithm in step S102 of FIG.

  In FIG. 6, the digital watermark embedding unit 202 sets A (j) as the embeddable data amount of the j-th page (step S111). The digital watermark embedding unit 202 sets P (i) as the data amount of the watermark data of the original i-th page (step S112). The digital watermark embedding unit 202 calculates the ratio P (i) / ΣP (i) of the watermark data of the original i page (step S113).

  The digital watermark embedding unit 202 sets i to 1 and j to 1 (step S114). The digital watermark embedding unit 202 determines whether or not the EOF (End · Of · File) of the electronic document 140 has been reached (step S115). If it is EOF, the process ends. On the other hand, if it is not EOF, the digital watermark embedding unit 202 has the data amount of the watermark data not yet assigned to any page among the watermark data of the original i page (the unembedded watermark amount of the original i page). Is larger than the ratio P (i) / ΣP (i) of the original page i watermark data and the embeddable data amount A (j) of page j (step S116). If the unembedded watermark amount of the original i-th page is equal to or less than P (i) / ΣP (i) × A (j), the digital watermark embedding unit 202 sets the data amount of the watermark data to be embedded next to the j-th page as the original The unembedded watermark amount for the i-th page is set (step S117). The digital watermark embedding unit 202 embeds the watermark data of the original i-th page with the set data amount on the j-th page (step S118). Then, i is incremented by 1, j is set to 1 (step S119), and the process returns to step S115. If the unembedded watermark amount of the original i-th page is larger than P (i) / ΣP (i) × A (j) in step S116, the digital watermark embedding unit 202 sets the data amount of the watermark data to be embedded next on the j-th page Is set to P (i) / ΣP (i) × A (j) (step S120). The digital watermark embedding unit 202 embeds the watermark data of the original i-th page of the set data amount on the j-th page (step S121). Then, j is incremented by 1 (step S122), and the process returns to step S115.

  As described above, the digital watermark embedding apparatus 200 (watermark generating apparatus) according to the present embodiment is characterized in that the watermark for each original page is efficiently distributed and embedded in all pages.

Embodiment 2. FIG.
In the present embodiment, differences from the first embodiment will be mainly described.

  In the first embodiment, the digital watermark embedding unit 202 divides the data amount of the divided data W (i, j) into the maximum data amount A (j) of the digital watermark that can be embedded in the jth page × embedding data X ( Data amount P (i) of i) / total data amount ΣP (i) from embedding data X (1) to X (n) is limited. On the other hand, in the present embodiment, the digital watermark embedding unit 202 limits the data amount of the divided data W (i, j) to a data amount P (i) ÷ m or more of the embedding data X (i). To do.

  FIG. 7 is a diagram illustrating an example of a watermark layout in the present embodiment.

  In FIG. 7, the digital watermark embedding unit 202 does not embed a watermark from the front as shown in the example of FIG.

In FIG. 7, the amount of watermark data is 1 Kbyte for the first page, 1 Kbyte for the second page, and 500 bytes for the third page, as in the example of FIG. Also, it is assumed that the amount of watermark data that can be embedded is 900 bytes per page (may vary from page to page). That is, in this example, n = m = 3, A (1) = A (2) = A (3) = 900 bytes, P (1) = 1,000 bytes, P (2) = 1,000 bytes , P (3) = 500 bytes. In this example, the data amounts of the divided data W (i, j) are equal as follows (if there is a remainder, the remainder is dispersed).
Data amount of divided data W (1,1) = data amount of divided data W (1,2) = data amount of divided data W (1,3) = P (1) ÷ 3 = 333 bytes or 334 bytes of divided data Data amount of W (2,1) = data amount of divided data W (2,2) = data amount of divided data W (2,3) = P (2) ÷ 3 = 333 bytes or 334 bytes divided data W ( 3, 1) data amount = divided data W (3,2) data amount = divided data W (3,3) data amount = P (3) / 3 = 166 bytes or 167 bytes

  The operation of the digital watermark embedding apparatus 200 is as follows.

  First, the data input unit 201 reads all pages and acquires watermark data of all pages, as in the example of FIG. That is, the data input unit 201 acquires the embedding data X (1) to X (3) from the electronic document 140 including three pages and writes it in the storage device 122.

  Next, the digital watermark embedding unit 202 divides the amount of watermark data for each page into three equal parts, and embeds a watermark in each page. As for the watermark data of the first page, 334 bytes are embedded in the first page of the original, 333 bytes are embedded in the second page of the original, and 333 bytes are embedded in the third page of the original (the second page or the third page instead of the first page). The eyes may be 334 bytes). In the watermark data of the second page, 334 bytes are embedded in the first page of the original, 333 bytes are embedded in the second page of the original, and 333 bytes are embedded in the third page of the original (the second page or the third page instead of the first page). The eyes may be 334 bytes). The watermark data of the third page is embedded with 167 bytes on the first page of the original, 167 bytes on the second page of the original, and 166 bytes on the third page of the original (3 pages instead of the first page or the second page) The eyes may be 167 bytes).

  In other words, when the digital watermark embedding unit 202 reads the embedding data X (1) written by the data input unit 201 in step S101 from the storage device 122, the read embedding data X (1) is approximately equal to three. The divided data W (1,1), W (1,2), and W (1,3) are generated. Then, the digital watermark embedding unit 202 embeds the generated divided data W (1,1), W (1,2), and W (1,3) as digital watermarks in the first to third pages, respectively. Similarly, when the digital watermark embedding unit 202 reads the embedding data X (2) written by the data input unit 201 in step S101 from the storage device 122, the read embedding data X (2) is reduced to three. Divided data W (2, 1), W (2, 2), W (2, 3) is generated by dividing equally. Then, the digital watermark embedding unit 202 embeds the generated divided data W (2,1), W (2,2), and W (2,3) as digital watermarks in the first to third pages, respectively. Similarly, when the digital watermark embedding unit 202 reads the embedding data X (3) written by the data input unit 201 in step S101 from the storage device 122, the read embedding data X (3) is reduced to three. Divided data W (3, 1), W (3, 2), W (3, 3) is generated by equally dividing. Then, the digital watermark embedding unit 202 embeds the generated divided data W (3, 1), W (3, 2), and W (3, 3) as digital watermarks in the first to third pages, respectively.

  Compared with the first embodiment, this embodiment has an effect that, for example, when the watermark data of only the second page of the original is desired, the same position only needs to be scanned for each page. If there is a remainder as in the above example, the watermark data may be embedded by shifting the position and embedding the watermark data at the same position for each page.

  As described above, the digital watermark embedding device 200 (watermark generating device) according to the present embodiment is characterized in that the data is distributed for each page and the watermark reading is made efficient.

Embodiment 3 FIG.
In the present embodiment, differences from the first embodiment will be mainly described.

  FIG. 8 is a block diagram illustrating a configuration example of the printing system 100 according to the present embodiment.

  In FIG. 8, the digital watermark embedding apparatus 200 includes a first page adding unit 203 in addition to a data input unit 201 and a digital watermark embedding unit 202. The other points are the same as in FIG.

  FIG. 9 is a flowchart showing the operation of the digital watermark embedding apparatus 200 (the digital watermark embedding method according to the present embodiment and the processing procedure of the digital watermark embedding program according to the present embodiment).

  In step S201 (data input processing) in FIG. 9, the data input unit 201 stores the electronic document 140 including n pages (n is an integer satisfying n> 1), as in step S101 in FIG. The information corresponding to each page of the read electronic document 140 is input and written in the storage device 122 as n embedding data (watermark data). For example, the data input unit 201 extracts the data of the i (i = 1, 2,..., N) th page from the electronic document 140 and embeds the data itself or the hash value of the data. To the storage device 122 as data X (i).

  In step S202 (first page addition processing), the first page addition unit 203 adds at least one page to the electronic document 140 stored in the storage device 122, and the electronic document 140 is m (m is m>). Change to an electronic document 140 consisting of n) integer pages. Here, it is sufficient for the first page adding unit 203 to add one page, and only one page is added. Even if it is sufficient to add one page, two or more pages may be added.

  In step S203 (digital watermark embedding process), the digital watermark embedding unit 202 reads each of the n embedding data written by the data input unit 201 in step S201 from the storage device 122. The digital watermark embedding unit 202 divides the read embedding data by the processing device 121 to generate m pieces of divided data. The digital watermark embedding unit 202 distributes the generated m pieces of divided data to n pages of the electronic document 140 and embeds them as a digital watermark. For example, when the digital watermark embedding unit 202 reads the embedding data X (i) from the storage device 122, the electronic watermark embedding unit 202 divides the read embedding data X (i) into m pieces of divided data W (i, j) (j = 1, 2, ..., m). Then, the digital watermark embedding unit 202 embeds the generated m pieces of divided data W (i, j) as a digital watermark in the jth page. In the present embodiment, as in the first embodiment, the digital watermark embedding unit 202 sets the data amount of the divided data W (i, j) to the maximum data amount A ( j) × data amount P (i) of embedding data X (i) / total data amount ΣP (i) from embedding data X (1) to X (n).

  FIG. 10 is a diagram showing an example of a watermark layout in the present embodiment.

In FIG. 10, the amount of watermark data is 1 Kbyte for the first page, 1 Kbyte for the second page, and 500 bytes for the third page, as in the example of FIG. The amount of watermark data that can be embedded is assumed to be 800 bytes per page (may vary from page to page). That is, in this example, n = 3, m = 4, A (1) = A (2) = A (3) = A (4) = 800 bytes, P (1) = 1,000 bytes, P ( 2) = 1,000 bytes, P (3) = 500 bytes, and ΣP (i) = 2,500 bytes. Therefore, in this example, the data amount of the divided data W (i, j) is limited as follows.
Data amount of divided data W (1,1) ≦ A (1) × P (1) ÷ ΣP (i) = data amount of divided data W (1,2) ≦ A (2) × P (1) ÷ ΣP (i) = data amount of 320-byte divided data W (1,3) ≦ A (3) × P (1) ÷ ΣP (i) = data amount of 320-byte divided data W (1,4) ≦ A (4) × P (1) ÷ ΣP (i) = data amount of 320-byte divided data W (2,1) ≦ A (1) × P (2) ÷ ΣP (i) = 320-byte divided data W (2 , 2) data amount ≦ A (2) × P (2) ÷ ΣP (i) = 320 byte divided data W (2,3) data amount ≦ A (3) × P (2) ÷ ΣP (i) = Data amount of 320-byte divided data W (2,4) ≦ A (4) × P (2) ÷ ΣP (i) = Data amount of 320-byte divided data W (3,1) ≦ A (1) × P (3) ÷ ΣP ( ) = Data amount of 160-byte divided data W (3,2) ≦ A (2) × P (3) ÷ ΣP (i) = Data amount of 160-byte divided data W (3,3) ≦ A (3) × P (3) ÷ ΣP (i) = 160 bytes Data amount of divided data W (3,4) ≦ A (4) × P (3) ÷ ΣP (i) = 160 bytes

  The operation of the digital watermark embedding apparatus 200 is as follows.

  First, the data input unit 201 reads all pages and acquires watermark data of all pages, as in the example of FIG. That is, the data input unit 201 acquires the embedding data X (1) to X (3) from the electronic document 140 including three pages and writes it in the storage device 122.

  Next, the digital watermark embedding unit 202 calculates the ratio of the watermark data for each page (with respect to the watermark data of all pages) (40% for the first page, 40% for the second page, and 20% for the third page). Become). The digital watermark embedding unit 202 embeds a watermark by maximizing the ratio of watermark data for each page. The watermark data of the first page is embedded with 320 bytes on the first page of the original, 320 bytes on the second page of the original, and 320 bytes on the third page of the original. Furthermore, since there are 40 bytes remaining, there is no fourth page in the original, but the first page adding unit 203 creates the fourth page with only the watermark. Then, the digital watermark embedding unit 202 embeds the remaining 40 bytes of the watermark data of the first page on the fourth page. The watermark data of the second page is embedded with 320 bytes on the first page of the original, 320 bytes on the second page of the original, and 320 bytes on the third page of the original. The digital watermark embedding unit 202 embeds the remaining 40 bytes of the watermark data of the second page on the fourth page. In the watermark data of the third page, 160 bytes are embedded in the first page of the original, 160 bytes are embedded in the second page of the original, and 160 bytes are embedded in the third page of the original. The digital watermark embedding unit 202 embeds the remaining 20 bytes of the watermark data of the third page on the fourth page.

  That is, when the digital watermark embedding unit 202 reads the embedding data X (1) written by the data input unit 201 in step S201 from the storage device 122, the read embedding data X (1) is 320 bytes or 320 bytes. , 320 bytes and the remaining 40 bytes are divided into four pieces to generate divided data W (1,1), W (1,2), W (1,3), and W (1,4). Then, the digital watermark embedding unit 202 applies the generated divided data W (1,1), W (1,2), W (1,3), and W (1,4) to the first to fourth pages, respectively. Embed as a watermark. Similarly, when the digital watermark embedding unit 202 reads the embedding data X (2) written by the data input unit 201 in step S201 from the storage device 122, the read embedding data X (2) is 320 bytes, 320 The divided data W (2,1), W (2,2), W (2,3), and W (2,4) are generated by dividing into four bytes of 320 bytes and the remaining 40 bytes. Then, the digital watermark embedding unit 202 applies the generated divided data W (2,1), W (2,2), W (2,3), and W (2,4) to the first to fourth pages, respectively. Embed as a watermark. Similarly, when the digital watermark embedding unit 202 reads the embedding data X (3) written by the data input unit 201 in step S201 from the storage device 122, the read embedding data X (3) is 160 bytes, 160 The divided data W (3, 1), W (3, 2), W (3, 3), and W (3, 4) are generated by being divided into four bytes of 160 bytes and the remaining 20 bytes. Then, the digital watermark embedding unit 202 applies the generated divided data W (3, 1), W (3, 2), W (3, 3), and W (3, 4) to the first to fourth pages, respectively. Embed as a watermark.

  In this example, the distribution pattern of the digital watermark is such that the digital watermark is embedded in order from the smallest page number, but other distribution patterns may be employed. For example, in the digital watermark embedding unit 202, the data amounts of the divided data W (1,1), W (1,2), W (1,3), and W (1,4) are 40 bytes, 320 bytes, and 320, respectively. The embedding data X (1) may be divided into bytes and 320 bytes, or divided data W (1,1), W (1,2), W (1,3), W (1, The embedding data X (1) may be divided so that the data amount of 4) is 300 bytes, 300 bytes, 200 bytes, and 200 bytes, respectively.

  As described above, the digital watermark embedding apparatus 200 (watermark generation apparatus) according to the present embodiment is characterized in that, when the watermark data does not fit on all pages, a watermark only page is added.

Embodiment 4 FIG.
The difference between the present embodiment and the third embodiment will be mainly described.

  In the third embodiment, as in the first embodiment, the digital watermark embedding unit 202 converts the data amount of the divided data W (i, j) into the maximum data amount A ( j) × data amount P (i) of embedding data X (i) / total data amount ΣP (i) from embedding data X (1) to X (n). On the other hand, in the present embodiment, as in the second embodiment, the digital watermark embedding unit 202 uses the data amount of the divided data W (i, j) as the data amount P (i) of the embedding data X (i). ÷ Limit to m or more.

  FIG. 11 is a diagram showing an example of a watermark layout in the present embodiment.

  In FIG. 11, the digital watermark embedding unit 202 does not embed a watermark from the front as shown in the example of FIG.

In FIG. 11, the amount of watermark data is 1 Kbyte for the first page, 1 Kbyte for the second page, and 500 bytes for the third page, as in the example of FIG. Also, it is assumed that the amount of watermark data that can be embedded is 800 bytes per page (may vary from page to page). That is, in this example, n = 3, m = 4, A (1) = A (2) = A (3) = A (4) = 800 bytes, P (1) = 1,000 bytes, P ( 2) = 1,000 bytes, P (3) = 500 bytes, and ΣP (i) = 2,500 bytes. In this example, the data amounts of the divided data W (i, j) are equal as follows (if there is a remainder, the remainder is dispersed).
Data amount of divided data W (1,1) = data amount of divided data W (1,2) = data amount of divided data W (1,3) = data amount of divided data W (1,4) = P ( 1) ÷ 4 = 250 bytes of divided data W (2,1) data amount = divided data W (2,2) data amount = divided data W (2,3) data amount = divided data W (2,4) ) Data amount = P (2) ÷ 4 = data amount of 250 byte divided data W (3,1) = data amount of divided data W (3,2) = data amount of divided data W (3,3) = Data amount of divided data W (3, 4) = P (3) ÷ 4 = 125 bytes

  The operation of the digital watermark embedding apparatus 200 is as follows.

  First, as in the example of FIG. 10, the data input unit 201 reads all pages and acquires watermark data of all pages. That is, the data input unit 201 acquires the embedding data X (1) to X (3) from the electronic document 140 including three pages and writes it in the storage device 122.

  Next, the digital watermark embedding unit 202 equally divides the data amount of the watermark data for each page into four, and embeds the watermark in each page. The watermark data of the first page is embedded with 250 bytes on the first page of the original, 250 bytes on the second page of the original, and 250 bytes on the third page of the original. Furthermore, the first page adding unit 203 creates 4 The remaining 250 bytes are embedded in the page. The watermark data of the second page is embedded with 250 bytes on the first page of the original, 250 bytes on the second page of the original, and 250 bytes on the third page of the original. The remaining 250 bytes are embedded in the page. As for the watermark data of the third page, 125 bytes are embedded in the first page of the original, 125 bytes are embedded in the second page of the original, and 125 bytes are embedded in the third page of the original. Furthermore, the first page adding unit 203 creates 4 The remaining 125 bytes are embedded in the page.

  That is, when the digital watermark embedding unit 202 reads the embedding data X (1) written by the data input unit 201 in step S201 from the storage device 122, the digital embedding data X (1) is equally divided into four. Thus, divided data W (1,1), W (1,2), W (1,3), and W (1,4) are generated. Then, the digital watermark embedding unit 202 applies the generated divided data W (1,1), W (1,2), W (1,3), and W (1,4) to the first to fourth pages, respectively. Embed as a watermark. Similarly, when the digital watermark embedding unit 202 reads the embedding data X (2) written by the data input unit 201 in step S201 from the storage device 122, the read embedding data X (2) is reduced to four or the like. The divided data W (2,1), W (2,2), W (2,3), and W (2,4) are generated. Then, the digital watermark embedding unit 202 applies the generated divided data W (2,1), W (2,2), W (2,3), and W (2,4) to the first to fourth pages, respectively. Embed as a watermark. Similarly, when the digital watermark embedding unit 202 reads the embedding data X (3) written by the data input unit 201 in step S101 from the storage device 122, the read embedding data X (3) is reduced to four or the like. The divided data W (3,1), W (3,2), W (3,3), and W (3,4) are generated. Then, the digital watermark embedding unit 202 applies the generated divided data W (3, 1), W (3, 2), W (3, 3), and W (3, 4) to the first to fourth pages, respectively. Embed as a watermark.

Embodiment 5 FIG.
In the present embodiment, differences from the first embodiment will be mainly described.

  FIG. 12 is a block diagram illustrating a configuration example of the printing system 100 according to the present embodiment.

  In FIG. 12, the digital watermark embedding apparatus 200 includes a second page addition unit 204 in addition to the data input unit 201 and the digital watermark embedding unit 202. The other points are the same as in FIG.

  FIG. 13 is a flowchart showing the operation of the digital watermark embedding apparatus 200 (the digital watermark embedding method according to the present embodiment and the processing procedure of the digital watermark embedding program according to the present embodiment).

  Step S301 (data input processing) and step S302 (digital watermark embedding processing) in FIG. 13 are the same as steps S101 and S102 in FIG.

  In step S303 (second page addition processing), the second page addition unit 204 causes the processing device 121 to generate the parity data of the digital watermark embedded by the digital watermark embedding unit 202 in step S302. The second page adding unit 204 adds a page on which the generated parity data is recorded to the electronic document 140.

  FIG. 14 is a diagram showing an example of a watermark layout in the present embodiment.

  In the example of FIG. 14, the parity of the watermark is generated in the horizontal direction in the example of FIG. 5 to generate a parity-only page so that the consistency of the watermark can be obtained (FIG. 7, FIG. 10, FIG. 11 examples). On the fourth page, the parity data of the data embedded in the same position of the first page, the second page, and the third page is embedded in the same position as the parity data of the watermark data of each page. For example, if the first bit of the first page is 1, the first bit of the first page is 0, and the first bit of the third page is 1, the first bit of the fourth page is their parity data 1 + 0 + 1 = 0 (in the case of even parity).

  As described above, digital watermark embedding apparatus 200 (watermark generation apparatus) according to the present embodiment is characterized in that the watermark parity of all pages is newly added.

  As mentioned above, although embodiment of this invention was described, you may implement combining 2 or more embodiment among these. Alternatively, one of these embodiments may be partially implemented. Or you may implement combining two or more embodiment among these partially.

  100 printing system, 110 client, 120 print server, 121 processing device, 122 storage device, 130 printer, 140 electronic document, 150 spool file, 200 digital watermark embedding device, 201 data input unit, 202 digital watermark embedding unit, 203 1st Page adder, 204 Second page adder, 211 Original all page watermark data acquisition function, 212 Watermark page data layout function, 213 Original digital watermark merge function, 901 LCD, 902 keyboard, 903 mouse, 904 FDD, 905 CDD, 911 CPU, 912 bus, 913 ROM, 914 RAM, 915 communication board, 920 HDD, 921 operating system, 922 window system, 923 programs, 24 file group.

Claims (8)

An electronic watermark embedding device for embedding an electronic watermark in an electronic document consisting of a plurality of pages,
A data input unit that inputs information corresponding to each page of the plurality of pages and writes the information to a storage device as a plurality of embedding data;
The embedding data of the plurality of embedding data written by the data input unit is read from the storage device, the embedding data read is divided by the processing device to generate a plurality of divided data, and the generated plurality of divided data An electronic watermark embedding device comprising: an electronic watermark embedding unit that embeds the image as a digital watermark in a distributed manner on the plurality of pages. The electronic document is composed of n pages (n is an integer satisfying n> 1),
The data input unit writes information corresponding to the i (i = 1, 2,..., N) th page as embedded data X (i) to the storage device,
When the digital watermark embedding unit reads the embedding data X (i) from the storage device, the digital watermark embedding unit divides the read embedding data X (i) to m (m is an integer where m = n) divided data W. (I, j) (j = 1, 2,..., M) is generated, and the generated m pieces of divided data W (i, j) are embedded as a digital watermark in the jth page. The digital watermark embedding apparatus according to claim 1. The electronic document is composed of n pages (n is an integer satisfying n> 1),
The digital watermark embedding device further includes:
A first page adding unit that adds at least one page to the electronic document and changes the electronic document to an electronic document having m (m is an integer satisfying m> n) pages;
The data input unit writes information corresponding to the i (i = 1, 2,..., N) th page as embedded data X (i) to the storage device,
When the digital watermark embedding unit reads the embedding data X (i) from the storage device, the digital watermark embedding unit divides the read embedding data X (i) into m pieces of divided data W (i, j) (j = 1, 2. The digital watermark embedding apparatus according to claim 1, wherein the generated m pieces of divided data W (i, j) are embedded as a digital watermark in the jth page. .   The digital watermark embedding unit divides the data amount of the divided data W (i, j) by (maximum data amount of digital watermark that can be embedded in the j-th page) × (data amount of embedding data X (i)) ÷ 4. The digital watermark embedding apparatus according to claim 2, wherein the electronic watermark embedding apparatus is limited to a value equal to or less than (total data amount from embedding data X (1) to X (n)).   The electronic watermark embedding unit limits the data amount of the divided data W (i, j) to (data amount of embedding data X (i)) / m or more. Digital watermark embedding device. The digital watermark embedding device further includes:
The electronic device includes a second page adding unit that generates parity data of the electronic watermark embedded by the electronic watermark embedding unit by a processing device and adds a page on which the generated parity data is recorded to the electronic document. The electronic watermark embedding device according to any one of 1 to 5. An electronic watermark embedding method for embedding an electronic watermark in an electronic document consisting of a plurality of pages,
A storage device of the computer stores information corresponding to each of the plurality of pages as a plurality of embedding data;
A processing device of a computer reads each embedding data of the plurality of embedding data from a storage device, divides the read embedding data to generate a plurality of divided data, and generates the plurality of divided data as the plurality of divided data An electronic watermark embedding method characterized in that it is embedded in a page as a digital watermark. An electronic watermark embedding program for embedding an electronic watermark in an electronic document consisting of a plurality of pages,
A data input process for inputting information corresponding to each page of the plurality of pages and writing the information as a plurality of embedding data in a storage device;
Each of the embedding data of the plurality of embedding data written by the data input process is read from the storage device, and the embedding data thus read is divided by the processing device to generate a plurality of divided data, and the generated plurality of divided data An electronic watermark embedding program for causing a computer to execute an electronic watermark embedding process for embedding a plurality of pages and embedding it as an electronic watermark.

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