JP2012114725A - Digital watermark embedding apparatus and digital watermark reading apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an embedding apparatus allowing information, which cannot be removed even by applying image processing after reading a printed document by a scanner, to be embedded as a digital watermark at high speed; and a reading apparatus allowing the digital watermark embedded by the embedding apparatus to be read at high speed.SOLUTION: The embedding apparatus includes a sentence file input part for inputting a sentence file; a watermark information input part for inputting watermark information to be embedded in the sentence file; an information storage part for storing a code corresponding to the watermark information; a section detection part for detecting a section for embedding the code from the sentence file; a character number operation part for calculating a number of increase/decrease in a number of characters in the section on the basis of the code; and a character number control part for increasing/decreasing the number of characters in the section on the basis of the calculated number of increase/decrease in the number of characters. The embedding apparatus further includes a watermark information embedding processing part for embedding the code in the sentence file.

Description

  The present invention relates to a digital watermark embedding device that embeds a digital watermark in a text file and a reading device that reads out the digital watermark embedded in the text file.

  Digital watermarking is known as a technique for embedding information that cannot be perceived by humans into digital contents such as text files and multimedia data such as images, video, and audio and reading the information as necessary. Digital watermarks are used for the purpose of preventing illegal acts such as unauthorized copying, unauthorized distribution, and falsification of content, and identifying the source of leakage when content is distributed illegally.

  As a method of embedding a digital watermark in a text file, a method of embedding by controlling the direction and thickness of lines constituting a character according to Patent Document 1, or a method of embedding by controlling a character interval according to Patent Document 2 There are embedding devices and reading devices for embedding those digital watermarks. The digital watermark embedded in the text file by these embedding devices remains in the printed document after the text file is printed, and can be read out by the reading device. Therefore, by embedding the user's identification code in the text file as a digital watermark at the time of printing, the identification code can be confirmed when an illegally distributed document is found, and the responsibility can be clarified. As a result, thorough document management and information leakage can be suppressed. However, the electronic watermark embedded in the printed document by the embedding device described in the cited document 1 or 2 is obtained by performing image processing such as thinning, thickening, distortion, etc. after reading the printed document with a scanner. It can be easily removed while maintaining the appearance. For this reason, the identification code embedded at the time of printing cannot be read out from a document copied by performing the above image processing, and it is often impossible to clarify the location of responsibility at the time of information leakage.

  Therefore, as described in Patent Document 3, by changing the positional relationship between the end-of-line character group constituting the end-of-line character unit and the line feed position, the above-described method is used after the printed document is read by a scanner using a method of embedding a digital watermark. There are embedding devices and reading devices that embed information that cannot be removed by applying image processing as a digital watermark.

Japanese Patent No. 4510092 Japanese Patent No. 3884997 JP 2002-26074 A

  However, the embedding device or reading device disclosed in Citation 3 that changes the positional relationship between the end-of-line character group and the line feed position requires a morpheme dictionary or a morpheme analysis process for analyzing the morpheme of the end-of-line character group. In addition, there is a problem that the processing speed of embedding or reading becomes slow due to a large processing amount.

  Therefore, the present invention has been made in view of the above-described problems of the prior art, and is an electronic device that can embed information that cannot be removed by applying the image processing after a printed document is read by a scanner as a digital watermark at high speed. It is an object of the present invention to provide a watermark embedding device and a digital watermark reading device that reads out an embedded digital watermark at high speed.

  A first feature of a digital watermark embedding device according to the present invention for solving the above problem is a digital watermark embedding device for embedding watermark information in a text file composed of a plurality of lines, wherein the text file inputs a text file. An input unit, a watermark information input unit that inputs watermark information to be embedded in a text file, an information storage unit that stores a code corresponding to the watermark information, a section detection unit that detects a section in which a code is embedded from a text file, and a code Watermark information embedding process for embedding codes in a text file, having a character number calculation unit that calculates the number of characters in a section based on the number of characters and a character number control unit that increases or decreases the number of characters in a section based on the calculated number of characters It is a summary to provide a part.

  According to this feature, the code embedded in the text file remains unremoved even if the text file is printed and read by a scanner and subjected to image processing such as thinning, thickening, and distortion.

  The second feature of the digital watermark embedding device of the present invention is that, in the watermark information embedding processing unit of the first feature, the number-of-characters computation unit increases or decreases the number of characters in the section so that the total number of characters in the section corresponds to the code. The gist is to calculate the number.

  A third feature of the digital watermark embedding device of the present invention is that, in the watermark information embedding processing unit of the first feature, the character number calculation unit is configured to determine the number of characters in the section so that the increase / decrease number of the number of characters in the section corresponds to the code. The gist is to calculate the number of changes.

  A fourth feature of the digital watermark embedding device of the present invention is that, in any one of the first to third watermark information embedding processing units, the character number control unit increases or decreases the number of characters by line feed.

The fifth feature of the digital watermark embedding device of the present invention is that, in any one of the first to third watermark information embedding processing units, the character number control unit increases or decreases the number of characters by increasing or decreasing the character spacing of the section. This is the gist.
According to such a feature, the unnaturalness of the text wrapping due to the embedding of the code can be reduced by aligning the text wrapping positions.

  The sixth feature of the digital watermark embedding device of the present invention is summarized in that, in the first to fifth watermark information embedding processing units, the section is from the beginning of the line to the end of the line.

  The seventh feature of the digital watermark embedding device of the present invention is summarized in that, in the first to fifth watermark information embedding processing units, the section is a sentence between feature characters.

  The eighth feature of the digital watermark embedding device of the present invention is that, in the first to seventh watermark information embedding processing units, the information storage unit stores the watermark information in association with a plurality of codes. To do.

  A first feature of the electronic watermark reading apparatus of the present invention is an electronic watermark reading apparatus that reads watermark information embedded in a text file composed of a plurality of lines, wherein the watermark information is converted into a code, A text file input unit for inputting a watermark information text file embedded as an information storage unit, an information storage unit for storing a code corresponding to the watermark information, and an information reading processing unit for reading out the digital watermark information embedded in the watermark information text file The information reading processing unit includes a section detecting unit for detecting a reading section for reading a code from the watermark information sentence file, a character number calculating unit for counting the number of characters in the detected reading section, and a code corresponding to the number of characters in the reading section. The gist is to include an information reading unit that identifies and reads watermark information.

  A second feature of the digital watermark reading apparatus of the present invention is a digital watermark reading apparatus that reads watermark information embedded in a text file composed of a plurality of lines. The watermark information is converted into a code as a code. Embedded in the watermark information text file, the text file input section for inputting the embedded watermark information text file and the original text file in which the watermark information is not embedded, the information storage section for storing the code corresponding to the watermark information, and the watermark information text file An information readout processing unit for reading out the digital watermark information, the information readout processing unit detecting a readout section for reading out the code from the watermark information sentence file, and a corresponding section corresponding to the readout section from the original sentence file Corresponding section detection unit to detect and corresponding to read section detected And character count calculation section that counts the number of characters and between, to identify the code corresponding to the difference between the number of characters in the corresponding section and reading section, and summarized in that and an information reading section for reading the watermark information.

  According to the present invention, an electronic watermark embedding device capable of embedding information that cannot be removed even when the above-described image processing is applied after a printed document is read with a scanner as an electronic watermark, and an electronic device that reads out the embedded electronic watermark at high speed It becomes possible to provide a watermark reading device.

It is a block diagram which shows the structure of the digital watermark embedding apparatus by 1st embodiment. It is a block diagram which shows the structure of the embedding process part of the digital watermark embedding apparatus by 1st embodiment. It is a flowchart which shows the operation | movement procedure of the digital watermark embedding apparatus by 1st embodiment. It is a figure which shows the example of the original text file of electronic watermark embedding object. It is a figure which shows the example of the watermark information embedded in a text file as a digital watermark. It is a figure which shows the example of rules, such as the relationship between the number of characters of one line and embedded information, and how to count characters, used in the digital watermark embedding device / reading device according to the first embodiment. It is a figure which shows the example of the text file which embedded the watermark information by the digital watermark embedding apparatus by 1st embodiment. It is a figure which shows the example of the text file which embedded the watermark information by the digital watermark embedding apparatus by 1st embodiment. It is a figure which shows the example of the text file which embedded the watermark information by the digital watermark embedding apparatus by 1st embodiment. It is a figure which shows the example of rules, such as the relationship between the number of characters of one line and embedded information, and how to count characters, used in the digital watermark embedding device / reading device according to the first embodiment. It is a block diagram which shows the structure of the electronic watermark reading apparatus by 1st embodiment. It is a block diagram which shows the structure of the read-out process part of the digital watermark read-out apparatus by 1st embodiment. It is a flowchart which shows the operation | movement procedure of the electronic watermark reading apparatus by 1st embodiment. It is a figure which shows the example of the watermark information read from the text file by the digital watermark reading apparatus by 1st embodiment. It is a figure which shows the example of the image which printed the text file which embedded the watermark information with the digital watermark embedding apparatus by 1st embodiment, and was read with the scanner. It is a figure which shows the example of the image which printed the text file which embedded watermark information with the digital watermark embedding apparatus by 1st embodiment, read with the scanner, and performed the thinning process. It is a figure which shows the example of the image which printed the text file which embedded watermark information with the digital watermark embedding apparatus by 1st embodiment, read with the scanner, and performed the thick line process. It is a figure which shows the example of the image which printed the text file which embedded the watermark information by the digital watermark embedding apparatus by 1st embodiment, read with the scanner, and performed the distortion process. It is a block diagram which shows the structure of the digital watermark embedding apparatus by 2nd embodiment. It is a block diagram which shows the structure of the embedding process part of the digital watermark embedding apparatus by 2nd embodiment. It is a flowchart which shows the operation | movement procedure of the digital watermark embedding apparatus by 2nd embodiment. It is a figure which shows the example of rules, such as the relationship between the total number of characters from the 1st character of a sentence to the end of a line, the embedded information, and the numbering method of characters used with the electronic watermark embedding apparatus and reading apparatus by 2nd embodiment. It is a figure which shows the example of the text file which embedded the watermark information with the digital watermark embedding apparatus by 2nd embodiment. It is a figure which shows the example of the text file which embedded the watermark information with the digital watermark embedding apparatus by 2nd embodiment. It is a figure which shows the example of the text file which embedded the watermark information with the digital watermark embedding apparatus by 2nd embodiment. It is a figure which shows the example of rules, such as the relationship between the total number of characters from the 1st character of a sentence to the end of a line, the embedded information, and the numbering method of characters used with the electronic watermark embedding apparatus and reading apparatus by 2nd embodiment. It is a block diagram which shows the structure of the electronic watermark reading apparatus by 2nd embodiment. It is a block diagram which shows the structure of the read-out process part of the digital watermark read-out apparatus by 2nd embodiment. It is a flowchart which shows the operation | movement procedure of the electronic watermark reading apparatus by 2nd embodiment. It is a figure which shows the example of the watermark information read from the text file by the digital watermark reading apparatus by 2nd embodiment.

  Hereinafter, a digital watermark embedding device and a digital watermark reading device according to an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
The present embodiment relates to an embedding device that embeds invisible information in a line by matching the number of characters included in one line with a predetermined number of characters, and a reading device that reads out the embedded information.

[Digital watermark embedding device]
FIG. 1 is a block diagram showing the configuration of the digital watermark embedding apparatus in the first embodiment. As shown in FIG. 1, a digital watermark embedding device 100 according to the present embodiment includes a text file input unit 110 that inputs a text file to be embedded with watermark information, a watermark information input unit 120 that inputs watermark information, and is included in one line. Information storage unit 130 that stores the correspondence between the number of characters to be embedded and information to be embedded as embedding rule information, an embedding processing unit 140 that performs digital watermark embedding processing, and an output unit 150 that outputs a text file in which watermark information is embedded. The

  FIG. 2 is a block diagram illustrating a configuration of the embedding processing unit 140. As shown in FIG. 2, the embedding processing unit 140 includes a section detecting unit 141 that detects a line from a sentence constituting the sentence file, and an information storage unit 130 that indicates the number of characters in the line when information is embedded in the detected line. The number-of-characters calculation unit 142 that calculates according to the embedding rule information stored in the number of characters, and the number-of-characters control unit 143 that increases or decreases the number of characters in the row so as to match the result of the number-of-characters calculation unit 142.

  Next, a digital watermark embedding method using the digital watermark embedding apparatus 100 will be described. FIG. 3 is a flowchart showing an operation procedure of the digital watermark embedding apparatus 100.

  As shown in FIG. 3, the original text file 160 to be embedded with the watermark information is input to the text file input section 110 (S101A), and the watermark information 170 composed of n pieces of information is input to the watermark information input section 120. (S102A).

  The input original text file 160 data and watermark information 170 are transferred to the embedding processing unit 140. The embedding processing unit 140 repeats the following procedure.

  First, the section detecting unit 141 detects one line that has the youngest line number counted from the first line and is not yet processed from the data of the original sentence file 160 (S103A).

  Next, the number-of-characters calculation unit 142 calculates the number of characters in the line when information is embedded in the detected line according to the embedding rule information 180 (S104A).

  Then, the number-of-characters control unit 143 embeds information corresponding to the calculation result by increasing or decreasing the number of characters in the line so as to match the calculation result of the character number calculation unit 142 (S105A), and updates the data of the original sentence file 160. (S106A).

  The repetition of the above procedure ends when no new row is detected in the section detection unit 141 (S107A).

  The data of the original text file 160 updated by the above procedure is output from the output unit 150 as a text file 161 in which the watermark information 170 is embedded (S108A).

  Hereinafter, the operation of the digital watermark embedding apparatus 100 will be described in detail using specific data.

  The original sentence file 162 in FIG. 4 is an example of the original sentence file 160. A line feed code is included at the end of each line of text. The first line 162-1 is 36 characters. The second line 162-2 is 37 characters. In the third line 162-3, up to "-" at the end of the line is 37 characters. The fourth line 162-4 is 10 characters in the number of characters up to “.” At the end of the line.

  The watermark information 171 in FIG. 5 is an example of the watermark information 170 and is a three-digit bit expressed in a binary number.

  The embedding rule information 181 in FIG. 6 is an example of embedding rule information 180 stored in the information storage unit 130, and indicates the correspondence between the number of characters in one line after embedding processing and the information to be embedded.

  The original sentence file 162 of FIG. 4 is input from the sentence file input unit 110, and the watermark information 171 of FIG. 5 is input from the watermark information input unit 120.

  The input original text file 162 data and watermark information 171 are passed to the embedding processing unit 140. The embedding processing unit 140 embeds information corresponding to the watermark information 171 in the data of the original sentence file 162 by the following procedure.

  FIG. 7 shows a sentence file 162a in which information corresponding to bit 0 which is the first bit of FIG. 5 is embedded in the first line of the original sentence file 162 of FIG. The procedure for embedding information corresponding to bit 0 of the watermark information 171 is as follows.

  First, the section detection unit 141 detects the first line 162-1 from the data of the original sentence file 162.

  Next, the number-of-characters computation unit 142 computes the number of characters in the first line corresponding to bit 0 according to the embedding rule information 181. First, it is read from the rule of the embedding rule information 181 that the number of characters corresponding to bit 0 in the first row is 36. Next, the number of characters in the first line 162-1 before embedding is counted and calculated to be 36. Next, the difference between the number of characters 36 corresponding to bit 0 and the number of characters 36 before embedding is calculated to obtain a change amount 0 of the number of characters.

  Next, the number-of-characters control unit 143 performs a process of changing the number of characters in the first line 162-1 based on the amount of change 0 in the number of characters. Since the amount of change in the number of characters is 0, the character number changing process is not performed. After performing the above processing, the data of the original sentence file 162 is updated to create a sentence file 162a.

  FIG. 8 shows a sentence file 162b in which information corresponding to bit 1 which is the second bit of FIG. 5 is embedded in the second line, following FIG. The procedure for embedding information corresponding to 1 of the second bit of the watermark information 171 is as follows.

  First, the section detection unit 141 detects the second line 162a-2 from the data of the text file 162a of FIG.

  Next, the number-of-characters computation unit 142 computes the number of characters in the second line corresponding to bit 1 according to the embedding rule information 181. First, it is read from the rule 2 of the embedding rule information 181 that the number of characters corresponding to bit 1 in the second row is 35. Next, the number of characters in the second line 162a-2 before embedding is counted and calculated to be 37. Next, the difference between the number of characters 35 corresponding to bit 1 and the number of characters 37 before embedding is calculated to obtain the amount of character change -2. Then, it is verified whether the number of characters in the second line 162b-2 can be reduced by two characters. First, the process of counting the number of characters by reducing the number of characters on the second line one by one is repeated, and the line feed position when the number of characters has decreased by two or more characters is obtained. When a line feed is made between the characters “out” and “se” at the position of −2 characters from the end of the line, the number of characters on the second line is 35. Therefore, it is possible to reduce two characters.

  Next, the number-of-characters control unit 143 performs a process of changing the number of characters in the second line 162a-2 based on the amount-of-character change-2. Since the change amount of the number of characters is −2, a line feed is performed between the character “out” and the character “se” at the position of −2 characters from the end of the second line 162a-2. After performing the above processing, the data of the text file 162a is updated to create the text file 162b.

  FIG. 9 shows a text file 162c in which information corresponding to bit 0, which is the third bit in FIG. 5, is embedded in the third line, following FIG. The procedure for embedding information corresponding to 0 of the third bit of the watermark information 171 is as follows.

  First, the section detection unit 141 detects the third line 162b-3 from the data of the text file 162b in FIG.

  Next, the number-of-characters calculation unit 142 calculates the number of characters in the third row corresponding to bit 0 according to the embedding rule information 181. First, it is read from rule 1 of the embedding rule information 181 that the number of characters corresponding to bit 0 in the third row is 36. Next, the number of characters in the third line 162b-3 before embedding is counted. The number of characters in the third line 162b-3 before embedding is 39 characters when counted up to "-" at the end of the line, but from the rule 5 of the embedding rule information 181, "-" at the end of the line is not counted as the number of characters. Next, the difference between the number of characters 36 corresponding to bit 0 and the number of characters 38 before embedding is calculated to obtain a character number variation -2. Then, it is verified whether the number of characters in the third line 162b-3 can be reduced by two characters. First, the process of counting the number of characters by reducing the number of characters on the third line one by one is repeated, and the line feed position when the number of characters decreases by two or more characters is obtained. When a line feed is made between the character “-” (the character immediately after the character “o”) and “ta” at the position of −1 character from the end of the line, the number of characters on the third line is determined from rule 5 of the embedding rule information 181. The number “o” is 35 because it is not counted in the number of characters, and is reduced by 3 characters from the original number of characters. Therefore, it cannot be reduced by 2 characters.

  As a result of the verification, when it is determined that the number of characters cannot be changed, the number of characters corresponding to bit 0 is read from rule 1 of the embedding rule information 181. If there is no other character number corresponding to bit 0, the number of characters is obtained according to rule 3. In this case, there are 38 other character numbers corresponding to bit 0. Therefore, the difference between the number of characters 38 corresponding to bit 0 and the number of characters 38 before embedding is calculated to obtain a change amount 0 of the number of characters. When the amount of change is 0, verification regarding whether or not the number of characters can be changed is omitted.

  Next, the number-of-characters control unit 143 performs a process of changing the number of characters in the third line 162b-3 based on the amount of change 0 in the number of characters. Since the amount of change in the number of characters is 0, no line feed is actually performed. After performing the above processing, the data of the original sentence file 162b is updated to create a sentence file 162c.

  All the watermark information 171 is embedded as described above. The subsequent lines are processed so that no information is embedded. First, the section detection unit 141 detects the fourth line 162c-4 from the data of the text file 162c of FIG.

  Next, the number-of-characters calculation unit 142 calculates the number of characters in the fourth line 162c-4 when no information is embedded in accordance with the embedding rule information 181. It is read from rule 3 of the embedding rule information 181 that the number of characters when no information is embedded in the fourth line 162c-4 is 34 or less or 39 or more. Next, the number of characters in the fourth line 162c-4 before embedding is counted. The number of characters in the fourth line 162c-4 on the fourth line before embedding is 10 up to “.” At the end of the line, but from the rule 5 of the embedding rule information 181, “.” At the end of the line cannot be included in the number of characters. 9 Next, the difference between the number of characters read from the rule 5 of the embedding rule 181 and the number of characters before embedding is calculated. Since the number of characters in the fourth line 162c-4 before embedding is 34 or less, it is within the range of the number of characters when no information is embedded in rule 3 of the embedding rule 181, and the amount of change in the number of characters is zero.

  Next, the number-of-characters control unit 143 performs a process for changing the number of characters in the fourth line 162c-4 based on the amount of change 0 in the number of characters. Since the amount of change in the number of characters is 0, no line feed is actually performed. After performing the above processing, the data of the original sentence file 162c is updated.

  The text file 162c generated by the above procedure is output from the output unit 150 as a text file in which the watermark information 171 is embedded.

  The original sentence file 162 used in the above description is an example, and embedding of the digital watermark according to the present embodiment can be applied to an arbitrary sentence file without departing from the gist.

  For example, the original sentence file may be in a data format in which lines are folded according to the sum of the character size and character spacing per line. In this case, in addition to the method of controlling the number of characters by adding a line feed code at the end of the line, a method of controlling the number of characters by changing the character spacing or character size may be used.

  The original sentence file may be a file including multimedia data such as images, sounds, and moving pictures in addition to the sentence to be embedded with the digital watermark. In that case, the section detection unit 141 identifies the multimedia data and the sentence, and detects a line from the sentence.

  The text of the original text file 161 used in the above description is written in Japanese, but the text in the original text file is in a language other than Japanese, such as English, Chinese, Korean, French, German, etc. It may be described.

The watermark information 171 used in the above description is an example, and the embedding of the digital watermark according to the present embodiment can be applied to arbitrary watermark information without departing from the gist.
For example, the watermark information may be information including numerical values and characters other than 0 or 1.

  The embedding rule information 181 used in the above description is an example, and the embedding of digital watermark according to the present embodiment can use arbitrary embedding rule information without departing from the gist.

  For example, the embedding rule information may include a restriction rule relating to the adjustment of the number of characters such that the number of characters included in one line should not be the number of characters that cause a line break in the middle of an English word or a numerical value.

  Further, the embedding rule information may include the correspondence between the number of characters included in one line and a plurality of information strings, and by using the embedding rule information 182 in FIG. 10, it is possible to embed up to 2 bits of information in each line. Therefore, the embedding device according to the present embodiment can embed a plurality of information as digital watermarks in each row.

  Further, the section detected by the section detection unit used in the above description may not be a line, but may be a section between punctuation marks or between character characters such as a determined character, character size, and character spacing.

[Digital watermark reading device]
FIG. 11 is a block diagram showing the configuration of the digital watermark reading apparatus in the first embodiment. As illustrated in FIG. 11, the digital watermark reading apparatus 101 according to the present embodiment reads a text file input unit 111 that inputs a text file in which watermark information is embedded, and reads the correspondence between the number of characters included in one line and the embedded information. The information storage unit 130 stores the rule information, the reading processing unit 190 that performs digital watermark reading processing, and the output unit 151 that outputs watermark information.

  FIG. 12 is a block diagram illustrating a configuration of the read processing unit 190. As shown in FIG. 12, the read processing unit 190 stores an interval detection unit 191 that detects a line from a sentence constituting a sentence file, a character number calculation unit 192 that counts the number of characters in the detected line, and an information storage unit 130. The information reading unit 193 reads out information corresponding to the result of the character number calculation unit 192 with reference to the read out rule information.

  Next, a digital watermark reading method using the digital watermark reading apparatus 101 will be described. FIG. 13 is a flowchart showing an operation procedure of the digital watermark reading apparatus 101.

  As shown in FIG. 13, a text file 161 in which watermark information is embedded is input to the text file input unit 111 (S101B).

  The input text file 161 data is transferred to the read processing unit 190. The read processing unit 190 repeats the following procedure.

First, the section detection unit 191 detects, from the data in the text file 161, one line that has the youngest line number counted from the first line and has not been processed yet (S102B).
Next, the number-of-characters calculation unit 192 counts the number of characters in the detected line (S103B).

  Then, the information reading unit 193 reads the information corresponding to the calculation result of the character number calculation unit 192 with reference to the read rule information 180 stored in the information storage unit 130 (S104B). The read information is temporarily stored in the information storage unit 130 (S105B).

  The repetition of the above procedure ends when no new row is detected in the section detection unit 191 (S106B).

  The information read by the above procedure and temporarily stored in the information storage unit 130 is output from the output unit 151 as the watermark information 170 (S107B).

Hereinafter, the operation of the digital watermark reading apparatus 101 will be described in detail using specific data.
The text file 162 c in which the watermark information of FIG. 9 is embedded is input from the text file input unit 111.

  The input data of the text file 162c is transferred to the read processing unit 190. The read processing unit 190 reads watermark information from the data of the text file 162c according to the following procedure.

  The procedure for reading the first bit of the watermark information is as follows. First, the section detection unit 191 detects the first line from the data of the text file 162c.

  Next, the number-of-characters calculation unit 192 counts the number of characters in the first line. In this case, the number of characters is 36.

  Then, the information reading unit 193 reads the bit 0 corresponding to the number of characters 36 with reference to the reading rule information 181 of FIG. 6 stored in the information storage unit 130. The read bit 0 is temporarily stored in the information storage unit 130.

  The procedure for reading the second bit of the watermark information is as follows. First, the section detection unit 191 detects the second line from the data of the text file 162c.

  Next, the number-of-characters calculation unit 192 counts the number of characters on the second line. In this case, the number of characters is 35.

  Then, the information reading unit 193 reads the bit 1 corresponding to the number of characters 35 with reference to the reading rule information 181 stored in the information storage unit 130. The read bit 1 is temporarily stored in the information storage unit 130 together with the bit 0 read from the first row.

  The procedure for reading the third bit of the watermark information is as follows. First, the section detection unit 191 detects the third line from the data of the text file 162c.

  Next, the number-of-characters calculation unit 192 counts the number of characters on the third line. In this case, the number of characters is 38.

  Then, the information reading unit 193 reads the bit 0 corresponding to the number of characters 38 with reference to the reading rule information 181 stored in the information storage unit 130. The read bit 0 is temporarily stored in the information storage unit 130 together with the bit 0 read from the first row and the bit 1 read from the second row.

  The procedure for reading the fourth bit of the watermark information is as follows. First, the section detection unit 191 detects the fourth line from the data of the text file 162c.

  Next, the number-of-characters calculation unit 192 counts the number of characters on the fourth line. In this case, the number of characters is nine.

Then, the information reading unit 193 reads NULL indicating that no information is embedded with reference to the read rule information 181 stored in the information storage unit 130.
This completes the reading process for all lines of the text file 162c.

  Information read by the above procedure and temporarily stored in the information storage unit 130 is output from the output unit 151 as watermark information 172 in FIG.

  The read watermark information 172 is equal to the watermark information 171 embedded in 162c by the digital watermark embedding apparatus in this embodiment. As described above, the digital watermark reading apparatus according to the present embodiment can read the watermark information embedded in the text file by the digital watermark embedding apparatus according to the present embodiment.

  The text file 162g in FIG. 15 is an image obtained by printing the text file 162c and reading it with a scanner.

  The text file 162h in FIG. 16 is an image obtained by performing thinning processing on the text file 162d in FIG.

  A text file 162i in FIG. 17 is an image obtained by performing thickening processing on the text file 162d in FIG.

  The text file 162j in FIG. 18 is an image obtained by performing distortion processing on the text file 162d in FIG. 15 in the 162j-1 direction.

  When the text file 162c and the text file 162g are compared, the number of characters included in each line is not changed by printing and scanning. Further, when the sentence file 162c and the sentence file 162h to the sentence file 162j are compared, the number of characters included in each line is not changed by each image processing.

  A text file that can be input to the digital watermark reading apparatus according to the present embodiment can be generated from the images of the text file 162h to the text file 162j by an existing OCR technique or by visually confirming and manually inputting text. . Thereby, a sentence file having the same sentence as the sentence in the image (the number of characters included in one line is equal) is generated, and the sentence file includes a sentence that is equal to the sentence file 162c.

  By inputting the sentence file generated from the images of the sentence file 162h to the sentence file 162j by the above method to the electronic watermark reading apparatus of the present embodiment, the watermark information embedded in the sentence in each image can be read out.

  As described above, the digital watermark embedded in the text file by the embedding device according to the present embodiment is applied to image processing such as thinning, thickening, and distortion after the text file is printed and read by the scanner. Is not removed. Therefore, it is possible to read the embedded digital watermark from a document copied by performing the image processing.

(Second embodiment)
The present embodiment relates to an embedding device that embeds invisible information in a line by increasing or decreasing the total number of characters from the first character of the sentence to the end of each line by a predetermined number of characters, and a reading device that reads out the embedded information thereby .

[Digital watermark embedding device]
FIG. 19 is a block diagram illustrating a configuration of a digital watermark embedding device according to the second embodiment. As shown in FIG. 19, the digital watermark embedding apparatus 200 according to the present embodiment includes a text file input unit 210 that inputs a text file to be embedded with watermark information, a watermark information input unit 220 that inputs watermark information, and a single character of the text. An information storage unit 230 that stores the correspondence between the amount of increase / decrease in the total number of characters from the eye to the end of each line and the embedded information as embedding rule information, an embedding processing unit 240 that performs digital watermark embedding processing, and a sentence file in which watermark information is embedded And an output unit 250 for outputting.

  FIG. 20 is a block diagram illustrating a configuration of the embedding processing unit 240. As shown in FIG. 20, the embedding processing unit 240 includes a section detecting unit 241 that detects a line from a sentence that constitutes a sentence file, and the first character of the sentence to the end of the line when information is embedded in the detected line. The number of characters is calculated according to the embedding rule information stored in the information storage unit 230, and the total number of characters from the first character of the sentence to the end of the line is increased or decreased so as to match the result of the character number calculation unit 242. And a character number control unit 243.

  Next, a digital watermark embedding method using the digital watermark embedding apparatus 200 will be described. FIG. 21 is a flowchart showing an operation procedure of the digital watermark embedding apparatus 200.

  As shown in FIG. 21, the original text file 260 to be embedded with the watermark information is input to the text file input section 210 (S201A), and the watermark information 270 composed of n pieces of information is input to the watermark information input section 220. (S202A).

  The input original text file 260 data and watermark information 270 are passed to the embedding processing unit 240. The embedding processing unit 240 repeats the following procedure.

  First, the section detection unit 241 detects the line that has the youngest line number counted from the first line and is not yet processed from the data of the original sentence file 260 (S203A).

  Next, the character number calculation unit 242 calculates the total number of characters from the first character of the sentence to the end of the line when information is embedded in the detected line according to the embedding rule information 280 (S204A).

  The character number control unit 243 embeds information corresponding to the calculation result by increasing or decreasing the total number of characters from the first character of the sentence to the end of the line so as to match the calculation result of the character number calculation unit 242 (S205A). The data of the text file 260 is updated (S206A).

  The repetition of the above procedure ends when no new line is detected in the section detection unit 241 (S207A).

  The data of the original sentence file 260 updated by the above procedure is output from the output unit 250 as a sentence file 261 in which the watermark information 270 is embedded (S208A).

  Hereinafter, the operation of the digital watermark embedding apparatus 200 will be described in detail using specific data.

  The embedding rule information 281 in FIG. 22 is an example of embedding rule information 280 stored in the information storage unit 230, and indicates the correspondence between the amount of increase / decrease in the total number of characters from the first character to the end of each line and the embedded information. .

  The original text file 162 of FIG. 4 is input from the text file input unit 210, and the watermark information 171 of FIG. 5 is input from the watermark information input unit 220. The first line 162-1 is 36 characters. The second line 162-4 is 37 characters. The third line 162-3 has 37 characters. The fourth line 162-4 has 10 characters.

  The input original text file 162 data and watermark information 171 are passed to the embedding processing unit 240. The embedding processing unit 240 embeds information corresponding to the watermark information 171 in the data of the original sentence file 162 by the following procedure.

  The procedure for embedding information corresponding to bit 0 of the first bit of watermark information 171 in FIG. 5 in the first row 162-1 is as follows. First, the section detection unit 241 detects the first line 162-1 from the data of the original sentence file 162 in FIG.

  Next, the total number of characters from the first character of the sentence corresponding to bit 0 to the end of the first line is calculated by the character number calculation unit 242 according to the embedding rule information 281. First, from the rules 1 and 4 of the embedding rule information 281, when the information corresponding to bit 0 is embedded in the first line 162-1, the number of characters is from the first character to the first line 162- It is read that one or more characters have decreased from the total number of characters up to the end of one line. Next, the total number of characters from the first character of the sentence before embedding to the end of the first line 162-1 is counted and calculated to be 36. Next, when the total number of characters up to the end of the first line 162-1 before embedding is reduced by one character from 36, the character at the end of the line becomes “i”, and from the rule 5 of the embedding rule information 281 to the end of the first line It is calculated that the total number of characters is 34.

  Next, one character from the end of the first line 162-1 is set by the character number control unit 243 so that the total number of characters from the first character of the sentence to the end of the first line 162-1 is 34 based on the calculation result. Make a line break at the eyes. After performing the above processing, the data of the original sentence file 162 is updated. FIG. 23 shows a text file 162d in which information corresponding to bit 0 is embedded in the first line.

  The procedure for embedding information corresponding to bit 1 of the second bit of watermark information 171 in the second row 162-2 is as follows. First, the section detection unit 241 detects the first line, 162d-1, and the second line 162d-2 from the data of the text file 162d in FIG.

  Next, the character number calculation unit 242 calculates the total number of characters from the first character of the sentence corresponding to bit 1 to the end of the second line according to the embedding rule information 281. First, from the rule 2 of the embedding rule information 281, when the information corresponding to bit 1 is embedded in the second line, the number of characters is the total from the first character of the sentence before embedding to the end of the first line 162d-2. Read the increase of one character or more from the number of characters. Next, the total number of characters from the first character of the sentence before embedding to the end of the second line 162d-2 is counted to calculate 73. In this count calculation, the rule 5 of the embedding rule information 281 is applied only to the row to be embedded. That is, the character at the end of the first line 162d-1 is “i”, but is counted as the number of characters. This is to reduce the application of rule 5 of the rule information 281 and perform the count operation at high speed. However, rule 5 of the embedding rule information 281 may be applied to a line other than the line to be embedded, and the number of characters may be counted.

  Next, the character number control unit 243 sets the number of characters in the second line 162d-2 to 1 so that the total number of characters from the first character of the sentence to the end of the line 162d-2 is 74 or more based on the calculation result. Increase letters. That is, one character is moved from the beginning of the third line 162d-3 of 162d to the end of the line 162d-2 of the second line. After performing the above processing, the data of the text file 162d is updated. FIG. 24 shows a text file 162e in which information corresponding to bit 0 is embedded in the first line and information corresponding to bit 1 is embedded in the second line.

  The procedure for embedding information corresponding to 0 of the third bit of the watermark information 171 is as follows. First, the section detection unit 141 detects the third line 162e-3 from the data of the text file 162e in FIG.

  Next, the number-of-characters calculation unit 142 calculates the total number of characters from the first character of the sentence to the end of the third line 162e-3 when information corresponding to bit 0 is embedded according to the embedding rule information 281. First, from rules 1 and 5 of the embedding rule information 281, the number of characters when information corresponding to bit 0 is embedded in the third line is from the first character of the text before embedding to the end of the third line 162 e-2. It is read that the total number of characters decreases by one or more characters. Next, the total number of characters from the first character of the sentence before embedding to the end of the third line 162e-3 is counted to calculate 109. At this time, the character at the end of the three lines before embedding is “tar”, and from the rule 5 of the embedding rule information 281, “−” is not counted in the number of characters before embedding. In addition, in this count calculation, rule 5 of the embedding rule information 281 is applied only to a row for which information is to be embedded. That is, the character at the end of the first line 162e-1 is “i”, but is counted as the number of characters. This is to reduce the application of rule 5 of the rule information 281 and perform the count operation at high speed. However, rule 5 of the embedding rule information 281 may be applied to a line other than the line to be embedded, and the number of characters may be counted. Next, in order to embed the information corresponding to bit 0, if the character “tar” is reduced by one character by performing a process of moving to the fourth line 162e-4, the character at the end of the third line is “o”. The total number of characters from rule 5 of the embedding rule information 281 to the end of the third line at that time is 106.

  Next, the number-of-characters control unit 243 sets the number of characters in the third line 162e-3 to 3 characters so that the total number of characters from the first character of the sentence to the end of the line 162e-3 becomes 106 based on the calculation result. cut back. That is, a line feed is performed at three characters from the end of the third line 162d-3 of 162d. After performing the above processing, the data of the text file 162e is updated. FIG. 25 shows a sentence file 162f in which information corresponding to bit 0 is embedded in bit 0 on the first line, bit 1 on the second line, and 162f-3 on the third line.

  All the watermark information 171 is embedded as described above. The subsequent lines are processed so that no information is embedded. First, the section detection unit 241 detects the fourth line 162f-4 from the data of the text file 162f in FIG.

  Next, the number-of-characters calculation unit 242 calculates the total number of characters from the first character to the end of the fourth line of the sentence when no information is embedded according to the embedding rule information 281. First, it is read from rule 3 of the embedding rule information 281 that the amount of increase / decrease in the total number of characters from the first character to the end of the fourth line 162e-4 is ± 0. Next, the total number of characters from the first character of the sentence before embedding to the end of the third line 162e-3 is counted and calculated to be 119. At this time, the character at the end of the four lines before embedding is “.”, And from rule 5 of the embedding rule information 281, “.” Is not counted in the number of characters before embedding. In addition, in this count calculation, rule 5 of the embedding rule information 281 is applied only to a row for which information is to be embedded. That is, the character at the end of the first line 162e-1 is “i”, but is counted as the number of characters. The rule 5 of the embedding rule information 281 may be applied to a line other than the line to be embedded, and the number of characters may be counted.

  Next, the character number control unit 243 increases or decreases the number of characters so that the total number of characters from the first character of the sentence to the end of the fourth line 162f-4 becomes 119. Since the number of characters before embedding is 119, the number of characters in the fourth line 162f-4 does not change. Also, the text file 162f does not change.

  Further, when it is read that the amount of increase / decrease of the total number of characters from the first character of the sentence before embedding to the end of the fourth line 162e-4 is ± 0, the subsequent calculation may be omitted. By omitting calculations, the processing speed is improved.

  Data of the text file 162f generated by the above procedure is output from the output unit 250 as a text file in which the watermark information 171 is embedded.

  As used in the above description, the digital watermark embedding device according to the present embodiment can handle the same original text file and watermark information as the digital watermark embedding device according to the first embodiment.

  The embedding rule information 281 used in the above description is an example, and any embedding rule information can be used for embedding the digital watermark according to the present embodiment without departing from the gist.

  For example, the embedding rule information may include a restriction rule relating to the adjustment of the number of characters such that the number of characters included in one line should not be the number of characters that cause a line break in the middle of an English word or a numerical value.

  In addition, the embedding rule information may include the correspondence between the increase / decrease amount of the total number of characters from the first character of the sentence to the end of each line and a plurality of information strings, and if embedding rule information 282 in FIG. Can be embedded. Therefore, the embedding device according to the present embodiment can embed a plurality of information as digital watermarks in each row.

[Digital watermark reading device]
FIG. 27 is a block diagram illustrating a configuration of a digital watermark reading apparatus according to the second embodiment. As shown in FIG. 27, the digital watermark reading apparatus 201 according to the present embodiment includes a text file input unit 211 that inputs an original text file in which watermark information is not embedded and a text file in which watermark information is embedded, and the first character of the text. From the information storage unit 230 that stores the correspondence between the amount of increase or decrease in the total number of characters from the end of each line and the embedded information as read rule information, the read processing unit 290 that performs digital watermark read processing, and the output unit 251 that outputs watermark information Composed.

  FIG. 28 is a block diagram illustrating a configuration of the read processing unit 290. As shown in FIG. 28, the read processing unit 290 detects from the section detection unit 291 that detects a line from the text that constitutes the text file, and the first text of the text in the text file in which the original text file and watermark information are embedded. From the number-of-characters calculation unit 292 that calculates the difference in the total number of characters up to the end of the line, and the information reading unit 293 that reads the information corresponding to the result of the number-of-characters calculation unit 292 with reference to the read rule information stored in the information storage unit 230 Composed.

  Next, a digital watermark reading method using the digital watermark reading device 201 will be described. FIG. 29 is a flowchart showing an operation procedure of the digital watermark reading apparatus 201.

  As shown in FIG. 29, an original sentence file 260 is input to the sentence file input unit 211 (S201B), and similarly a sentence file 261 in which watermark information is embedded is input (S202B).

  The input data of the original text file 260 and the data of the text file 261 are transferred to the read processing unit 290. The read processing unit 290 repeats the following procedure.

  First, the section detecting unit 291 detects from the data of the original sentence file 260 the line that has the youngest line number counted from the first line and has not been processed, and detects from the data of the sentence file 261 from the data of the original sentence file 260. A line corresponding to the selected line is detected (S203B).

  Next, the difference between the total number of characters from the first character of the sentence of the sentence file 261 to the end of the line detected by the character number calculation unit 292 and the total number of characters from the first character of the sentence of the original sentence file 260 to the detected end of line ( A value obtained by subtracting the latter from the former) is obtained (S204B).

  Then, the information reading unit 293 refers to the read rule information 280 stored in the information storage unit 230 and reads information corresponding to the calculation result of the character number calculation unit 292 (S205B). The read information is temporarily stored in the information storage unit 230 (S206B).

  The repetition of the above procedure ends when no new row is detected in the section detection unit 291 (S207B).

  The information read out by the above procedure and temporarily stored in the information storage unit 230 is output as watermark information 270 from the output unit 251 (S208B).

  Hereinafter, the operation of the digital watermark reading apparatus 201 will be described in detail using specific data.

  The original text file 162 in FIG. 4 and the text file 162 f in which the watermark information in FIG. 25 is embedded are input from the text file input unit 211.

  The input data of the text file 162 and the data of the text file 162f are transferred to the read processing unit 290. The read processing unit 290 reads watermark information from the data of the text file 162f according to the following procedure.

  The procedure for reading the first bit of the watermark information is as follows. First, the section detection unit 291 detects the first line from the data of the original sentence file 162 and detects the first line from the data of the sentence file 162f.

  Next, the number-of-characters calculation unit 292 makes a difference between the total number of characters from the first character of the sentence of the sentence file 162f to the end of the first line and the total number of characters from the first character of the sentence of the original sentence file 162 to the end of the first line (the former to the latter). Subtracted value). In this case, the character number difference (increase / decrease amount) is -2.

  Then, the information reading unit 293 reads the bit 0 corresponding to the increase / decrease amount −2 with reference to the read rule information 281 of FIG. 22 stored in the information storage unit 230. The read bit 0 is temporarily stored in the information storage unit 230.

  The procedure for reading the second bit of the watermark information is as follows. First, the section detection unit 291 detects the second line from the data of the original sentence file 162 and detects the second line from the data of the sentence file 162f.

  Next, the number-of-characters calculation unit 292 makes a difference between the total number of characters from the first character to the end of the second line of the sentence in the sentence file 162f and the total number of characters from the first character to the end of the second line of the sentence in the original sentence file 162 (from the former to the latter). Subtracted value). In this case, the character number difference (increase / decrease amount) is +1.

  Then, the information reading unit 293 reads the bit 1 corresponding to the increase / decrease amount + 1 with reference to the read rule information 281 of FIG. 22 stored in the information storage unit 230. The read bit 1 is temporarily stored in the information storage unit 230.

  The procedure for reading the third bit of the watermark information is as follows. First, the section detection unit 291 detects the third line from the data of the original sentence file 162 and detects the third line from the data of the sentence file 162f.

  Next, the number-of-characters calculation unit 292 makes a difference between the total number of characters from the first character to the end of the third line of the sentence in the sentence file 162f and the total number of characters from the first character to the end of the third line of the sentence in the original sentence file 162 (the former to the latter). Subtracted value). In this case, the character number difference (increase / decrease amount) is -3.

  Then, the information read unit 293 reads the bit 0 corresponding to the increase / decrease amount −3 with reference to the read rule information 281 of FIG. 22 stored in the information storage unit 230. The read bit 0 is temporarily stored in the information storage unit 230.

  The procedure for reading the fourth bit of the watermark information is as follows. First, the section detection unit 291 detects the fourth line from the data of the original sentence file 162 and detects the fourth line from the data of the sentence file 162f.

  Next, the number-of-characters calculation unit 292 makes a difference between the total number of characters from the first character of the sentence of the sentence file 162f to the end of the fourth line and the total number of characters from the first character of the sentence of the original sentence file 162 to the end of the four lines (the former to the latter). Subtracted value). In this case, the difference in the number of characters (increase / decrease amount) is zero.

Then, the information reading unit 293 refers to the read rule information 281 of FIG. 22 stored in the information storage unit 230, and reads NULL which means that no information is embedded.
This completes the reading process for all the lines of the text file 162f.

  Information read by the above procedure and temporarily stored in the information storage unit 230 is output from the output unit 251 as the watermark information 271 in FIG.

  The read watermark information 271 is equal to the watermark information 171 embedded in 162f by the digital watermark embedding apparatus in this embodiment. As described above, the digital watermark reading apparatus according to the present embodiment can read the watermark information embedded in the text file by the digital watermark embedding apparatus according to the present embodiment.

  Similarly to the digital watermark embedded in the text file by the embedding device according to the first embodiment, the digital watermark embedded in the text file by the embedding device according to the present embodiment prints the text file, and the scanner Even if image processing such as thinning, thickening, distortion, etc. is applied after reading with, it is not removed. Therefore, it is possible to read the embedded digital watermark from a document copied by performing the image processing.

100, 200 Digital watermark embedding device 101, 201 Digital watermark reading device 110, 111, 210, 211 Text file input unit 120, 220 Watermark information input unit 130, 230 Information storage unit 140, 240 Embed processing units 141, 191, 241, 291 Section detection unit 142, 192, 242, 292 Character number calculation unit 143, 243 Character number control unit 150, 151, 250, 251 Output unit 160, 162, 260 Original sentence file 161, 162a, 162b, 162c, 162d, 162e, 162f 162g, 162h, 162i, 162j, 261 Watermark embedded text file 170, 171, 172, 270, 271 Watermark information 180, 181, 182, 280, 281, 282 Embedding (reading) rule 190, 90 read processor 193,293 information reading unit

Claims (10)

An electronic watermark embedding device for embedding watermark information in a text file composed of a plurality of lines,
A text file input unit for inputting the text file;
A watermark information input unit for inputting the watermark information to be embedded in the sentence file;
An information storage unit for storing a code corresponding to the watermark information;
Based on the section detection unit for detecting the section in which the code is embedded from the sentence file, the number of characters calculation unit for calculating the number of increase / decrease in the number of characters in the section based on the code, and based on the calculated number of increase / decrease in the number of characters An electronic watermark embedding device, comprising: a character number control unit that increases or decreases the number of characters in a section, and a watermark information embedding processing unit that embeds the code in the sentence file.   The digital watermark embedding apparatus according to claim 1, wherein the number-of-characters calculation unit calculates an increase / decrease number of characters in the section so that the number of characters in the entire section corresponds to the code.   The digital watermark embedding apparatus according to claim 1, wherein the number-of-characters calculation unit calculates the number of increase / decrease in the number of characters in the section so that the number of increase / decrease in the number of characters in the section corresponds to the code.   The electronic watermark embedding apparatus according to claim 1, wherein the character number control unit increases or decreases the number of characters by a line feed.   The electronic watermark embedding apparatus according to claim 1, wherein the number-of-characters control unit increases or decreases the number of characters by increasing or decreasing a character interval of the section.   6. The digital watermark embedding apparatus according to claim 1, wherein the section is from the beginning of the line to the end of the line.   The digital watermark embedding apparatus according to claim 1, wherein the section is a sentence between characteristic characters.   8. The digital watermark embedding device according to claim 1, wherein the information storage unit stores the watermark information in association with a plurality of the codes. An electronic watermark reading device for reading watermark information embedded in a text file composed of a plurality of lines,
A text file input unit for converting the watermark information into a code and inputting a watermark information text file embedded as a code;
An information storage unit for storing a code corresponding to the watermark information;
An information readout processing unit for reading out the digital watermark information embedded in the watermark information sentence file,
The information readout processing unit
A section detecting unit for detecting a reading section for reading the code from the watermark information sentence file;
A number-of-characters calculation unit that counts the number of characters in the read section detected;
An electronic watermark reading apparatus comprising: an information reading unit that identifies the code corresponding to the number of characters in the reading section and reads the watermark information. An electronic watermark reading device for reading watermark information embedded in a text file composed of a plurality of lines,
A text file input unit for inputting a watermark information text file in which the watermark information is converted into a code and embedded as a code; and an original text file in which the watermark information is not embedded;
An information storage unit for storing a code corresponding to the watermark information;
An information readout processing unit for reading out the digital watermark information embedded in the watermark information sentence file,
The information readout processing unit
A section detecting unit for detecting a reading section for reading the code from the watermark information sentence file;
A corresponding section detecting unit for detecting a corresponding section corresponding to the read section from the original sentence file;
A number-of-characters calculation unit that counts the number of characters in the read section and the corresponding section detected;
An electronic watermark reading apparatus comprising: an information reading unit that identifies the code corresponding to the difference in the number of characters between the reading section and the corresponding section and reads the watermark information.

Images