JP2006013581A - Image processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processor capable of specifying a falsification-detected part more efficiently. <P>SOLUTION: The image processor is provided with an image accumulating/managing feature for accumulating and managing multiple image data. In the processor, a predetermined function operation is performed on the basis of the contents of the image data to calculate an identifier having a value uniquely defined from the contents of the image data, and the identifier is used to detect the falsification of the image data to be accumulated and managed. In contrast, for the falsified image data in which the falsification is recognized, the image data accumulated in the image accumulating/managing feature is compared with the falsified image data, thereby specifying the falsified part of the falsified image data. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image processing apparatus having an image storage management function for storing and managing a large number of image data.

  Generally, there is an electronic signature as a means for verifying falsification of digital data such as image data. In the electronic signature, signature information is created from data to be guaranteed, and the information is stored in a part of the image file or in another file. At the time of verification, signature information is created again from the image data, and the presence or absence of falsification is determined by comparing with the original signature information stored in the image file or another file.

  For example, an original image and a watermark image corresponding to the original image are respectively registered in the management device, a composite image that is suspected of being tampered with is compared with an original image registered in the management device, and the watermark is calculated from the difference. An image is extracted, and the extracted watermark image is compared with a watermark image registered in advance in the management apparatus. If the result does not match, it is determined that the image has been tampered (see Patent Document 1). ).

Alternatively, watermark image embedding is used to determine whether or not tampering has occurred and to specify the tampering location (see Patent Documents 2 and 3).
JP-A-11-98344 Japanese Patent Laid-Open No. 10-208026 JP 2002-247333 A

  However, the conventional method using the electronic signature can be handled only in a specific file format because it is necessary to store the signature information in the file. In addition, it is a determination as to whether or not the original is the verification result, and there is a problem that it is not possible to specify the falsified part.

  Further, the method disclosed in Patent Document 1 requires that an original image and a watermark image corresponding to the original image be registered in advance, which is a great practical limitation. This is because the image data has a large amount of information, and the process of comparing the images is a very heavy process.

  Further, the method disclosed in Patent Literature 2 enables verification of subsequent tampering by embedding watermark information. However, once a watermark is embedded, information beyond that is regarded as information embedding falsification, so information embedding can be performed only once.

  In the method disclosed in Patent Document 3, the falsification verification data embedding unit embeds the falsification verification data in the least significant bit of each pixel, and the falsification verification data embedding unit imitates the falsification verification data with the pixel value of each pixel. On the other hand, the information embedding means embeds embedded data in the least significant bit of each pixel, divides the embedding position into a plurality of blocks, performs information embedding a plurality of times, and embeds specific bits in each block. Resolves the problem that information embedding can only be performed once because it can be added by preventing overwriting previously embedded information as information indicating whether or not it has been completed, and has falsification verification and / or information extraction means In addition, a digital image data processing method with improved tamper detection reliability is provided.

  However, digital watermarking is a method of embedding information in an image so as not to cause deterioration of the image. However, as the amount of information increases, the deterioration of the image increases. In Cited Document 3, although the embedding position is divided into a plurality of blocks and information is embedded, the falsification position can be specified. However, if the falsification position is specified more accurately, the degradation of the image increases.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an image processing apparatus that can more efficiently identify a falsification detection location.

  In an image processing apparatus having an image accumulation management function for accumulating and managing a large number of image data, the present invention performs a predetermined function calculation based on the contents of the image data, and a value uniquely determined by the contents of the image data Is used to detect falsification of image data to be stored and managed, and for falsified image data that has been confirmed to be falsified, the image data stored in the image storage management function and the falsified By comparing the image data, the falsified location of the falsified image data is specified.

  The predetermined function calculation is a hash function calculation, and the identifier is a hash value obtained as a result of the hash function calculation.

  The identifier is inserted into the output image data.

  The identifier is inserted into the header area of the output image data.

  The identifier is inserted as a digital watermark in the data area of the output image data.

  The identifier is inserted into the image data when the image data is stored by the image storage management function.

  The identifier is inserted into the image data when the image data is output to the outside by the image storage management function.

  Further, when the image data obtained by reading the image of the read original using the original reading function is stored by the image accumulation management function, the identifier is calculated for the image data, An identifier is inserted into the image data.

  Further, the image processing apparatus further comprises an interface function with an external device, and when the image data received by the storage request from the external device via the interface function is stored by the image storage management function, the identifier is set for the image data. The identifier is calculated and the identifier is inserted into the image data.

  The image processing apparatus further includes a communication function for connecting to a network and communicating with another device via the network, storing image data received via the communication function, and receiving the image data as the image storage management function. Is stored, the identifier is calculated for the image data, and the identifier is inserted into the image data.

  Further, the electronic mail communication function further includes an electronic mail communication function for connecting to a network and exchanging information with other devices using the electronic mail via the network, and is attached to the electronic mail received via the electronic mail communication function. In addition to storing image data, when the received image data is stored by the image storage management function, the identifier is calculated for the image data and the identifier is inserted into the image data.

  Further, when the identifier is inserted in the image data stored by the image accumulation management function, the identifier for inspection is calculated for the image data by executing the predetermined function calculation, and the calculated The alteration of the image data is detected by comparing the identifier for inspection with the inserted identifier.

  Further, when falsification of the image data is detected, a message to that effect is displayed to the user.

  Further, when the alteration of the image data is detected, a message to that effect is displayed to the user, and the alteration location of the altered image data where the alteration is detected is displayed.

  Further, when falsification of the image data is detected, a falsification location of the falsified image data in which the falsification is detected is recorded and output.

  Therefore, according to the present invention, the alteration location can be identified by directly comparing the image data to be altered and the image data that has not been altered, so that the processing of the image data can be minimized, And the effect that specification of a tampering part can be performed more correctly is acquired.

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

  FIG. 1 shows an example of a network system according to an embodiment of the present invention.

  This network system includes a server device SV, a plurality of data processing devices DT1 to DTn, an image processing device PI, and a router device RT connected to a local area network LAN.

  Here, the server apparatus SV provides a well-known e-mail collection and distribution service to the user who uses the data processing apparatuses DT1 to DTn connected to the local area network LAN and the image processing apparatus PI. It has various server functions such as a mail server function.

  The local area network LAN is connected to the Internet via the router device RT, whereby the server device SV, the data processing devices DT1 to DTn, and the image processing device PI are connected to the Internet or other local area networks. Various data can be exchanged with a host device or the like connected to the network.

  The data processing devices DT1 to DTn include application software for creating and displaying various information (including image data) and various software for exchanging various data via the local area network LAN. Various programs such as these are introduced and used by a specific user. Here, the specific user may be one or a plurality of users.

  Further, the image processing apparatus PI has an e-mail processing function for exchanging image data and the like as an e-mail, an image reading function, an image storage function, and the like. In addition, the image processing apparatus PI is connected to the function of accessing the image data stored in the external storage medium MM by attaching the external storage medium MM, and the data processing apparatus DX. It also has a function to receive image data.

  FIG. 2 shows a configuration example of the image processing apparatus PI.

  In FIG. 1, a system control unit 1 performs various control processes such as a control process of each unit of the image processing apparatus PI, and a system memory 2 stores a control processing program executed by the system control unit 1 and a process In addition to storing various data necessary for executing the program, it constitutes a work area of the system control unit 1, and the parameter memory 3 stores various information unique to the image processing apparatus PI. The clock circuit 4 outputs current time information.

  The scanner 5 is for reading a document image with a predetermined resolution and full color, the plotter 6 is for recording and outputting an image with a predetermined resolution, and the character generator 7 is a figure to be inserted into image data. This is for generating character pattern data such as characters.

  The magnetic disk device 8 is for accumulating a large number of image data (image accumulating function) or for accumulating various other data. The image processing unit 9 converts the format of the image data, and an identifier (described later). ) Is inserted into the image data file, and an identifier recognition process for recognizing the identifier is realized. The operation display unit 10 allows the user to operate the image processing apparatus PI. It consists of various operation keys and various displays.

  The external interface circuit 11 connects the data processing device DX and exchanges various data with the data processing device DX. The storage medium reading / writing device 12 attaches and detaches the external storage medium MM. Thus, the data stored in the external storage medium MM is read out or the data is written in the external storage medium MM. The media interface circuit 13 is connected to the storage medium reading / writing device 12 to store the data. This is for controlling the operation of the medium reading / writing device 12.

  The local area network interface circuit 14 is for connecting the image processing device PI to the local area network LAN, and the local area network transmission control unit 15 is connected to other data terminal devices via the local area network LAN. It is for executing communication control processing of various predetermined protocol suites for exchanging various data between them.

  The system control unit 1, the system memory 2, the parameter memory 3, the clock circuit 4, the scanner 5, the plotter 6, the character generator 7, the magnetic disk device 8, the image processing unit 9, the operation display unit 10, the external interface circuit 11, The media interface circuit 13 and the local area network transmission control unit 15 are connected to an internal bus 16, and data exchange between these elements is mainly performed via the internal bus 16.

  FIG. 3 shows a configuration example of the data processing device DT (DT1 to DTn).

  In the figure, a CPU (Central Processing Unit) 21 controls the operation of the data processing unit DT, and a ROM (Read Only Memory) 22 is a program executed when the CPU 21 starts up, necessary data, etc. RAM (Random Access Memory) 23 is used to configure a work area of the CPU 21 and the like.

  The character generator 24 is for generating graphic character display data, the clock circuit 25 is for outputting current date and time information, and the local area network interface circuit 26 is connected to the data processing device DT. The local area network transmission control unit 27 is used to connect to a local area network LAN. The local area network transmission control unit 27 performs various kinds of predetermined data for exchanging various data with other data terminal devices via the local area network LAN. This is for executing the communication control processing of the protocol suite.

  The magnetic disk device 28 is for storing various data such as various application programs, work data, file data, image information data, and the CD-ROM device 29 is a CD-ROM which is an exchangeable recording medium. The CRT screen display device 31 is for reading the data in the ROM 30. The CRT screen display device 31 is for displaying a screen for operating the data processing device DT, and the display control unit 32 is for the CRT screen display device 31. This is for controlling display contents.

  The keyboard device 33 is for performing various key operations on the data processing device DT, and the screen instruction device 34 is for performing operation operations such as indicating an arbitrary point on the CRT screen display device 31. The input control unit 35 is for capturing input information of the keyboard device 33 and the screen instruction device 35.

  The CPU 21, ROM 22, RAM 23, character generator 24, clock circuit 25, local area network transmission control unit 27, magnetic disk device 28, CD-ROM device 29, display control unit 32, and input control unit 35 are connected to an internal bus. The data exchange between these elements is mainly performed through the internal bus 35.

  Here, in the present embodiment, basically, data exchange between terminals connected to the local area network LAN is a transmission protocol up to a transport layer called TCP / IP, and more. This is performed by applying a combination with a higher layer communication protocol (so-called protocol suite). For example, in the exchange of e-mail data, a communication protocol called SMTP (Simple Mail Transfer Protocol) is applied as an upper layer communication protocol.

  In addition, as a protocol that each terminal applies to the server device SV for confirmation of receipt of an e-mail addressed to the user, an acquisition request, or the like, a so-called POP (Post Office Protocol) can be applied.

  Further, communication protocols such as TCP / IP, SMTP, POP, and data format and data structure of e-mail are defined by RFC documents issued from IETF. For example, RFC is defined as RFC793, IP is defined as RFC793, SMTP is defined as RFC821, and e-mail formats are defined in RFC822, RFC1521, and RFC1522 (MIME (Multipurpose Mail Extension) format).

  In this embodiment, the image storage area provided in the magnetic disk device 8 is used to store images, and an image storage management function is provided so that the stored images can be used from other devices.

  Then, an identifier that can uniquely identify the image data is assigned to the image data managed by using the image accumulation management function, and an image output from the image processing apparatus PI using the identifier is provided. Data tampering can be detected.

  Here, the identifier can be calculated, for example, by applying a predetermined hash function operation to the contents of the image data.

  The hash value calculated by the hash function calculation always matches when the contents of the image data to be calculated are the same.

  On the other hand, if the image data that is the object of computation has undergone some alteration, the content of the image data to be altered is different from the initial content, so the same hash function computation is applied to the image data to be altered. The hash value obtained by applying is always different from the hash value corresponding to the image data before falsification.

  Therefore, by using this hash value as an identifier, it is possible to appropriately detect falsification of image data.

  Further, the falsified image data in which falsification is detected is compared with the image data that has not been falsified (hereinafter referred to as “reference image data”) stored in the magnetic disk device 8 of the image processing apparatus PI. Specify the falsification location of the image data.

  At the same time, the user is notified that the falsification has occurred, and the specified falsification location is displayed. In addition, the falsified location is recorded and output at the request of the user. As a display method of the tampered part, for example, there is a method of displaying image data for one sheet and displaying the tampered part with different display attributes such as surrounding with a wavy line. Further, at the time of recording and outputting the falsified portion, the falsified portion may be made conspicuous with a print attribute that can clearly recognize the falsified portion.

  By doing in this way, in the present embodiment, it is possible to appropriately specify the falsification location while minimizing the processing to the image data.

  Here, the identifier can be inserted into the header area (header information) of the image data file, or can be inserted into the image data of the image data file using digital watermark technology. Since the digital watermark technology (method for inserting digital watermark into image data, method for removing digital watermark data inserted into image data, etc.) is a well-known technology, detailed description thereof is omitted.

  The identifier can be inserted into the image data when the image data is stored in the magnetic disk device 8 or when the image data is output to the outside. As to which one is adopted, the user can set and register it in the image processing apparatus PI.

  For example, as shown in FIG. 4A, the image data file has an image data storage format configured with two areas of header information and image data main body. Here, the header information includes a file name, an image format, an image size, the number of bits per pixel, a time stamp indicating the created date and time, and comment information, as shown in FIG.

  Usually, user-defined information can be used as the comment information, so an identifier is inserted in this portion. For example, as shown in FIG. 4C, an information element including an identifier information code for displaying that the information is an identifier and identifier data can be set.

  Any image data storage format other than those described above can be adopted as long as it has a header area that can carry an information element corresponding to comment information.

  Further, in the present embodiment, in the data processing devices DT1 to DTn connected via the local area network LAN, for example, when image data is attached to the received electronic mail, The above-described image data alteration detection operation is performed. Alternatively, the image data tampering detection operation described above is performed on the image data read from the CD-ROM 30 mounted on the CD-ROM device 29.

  When the data processing devices DT1 to DTn detect falsification of the image data, the image processing device PI is used to specify the falsification location of the image data (image data to be falsified) determined to have been falsified. (Hereinafter referred to as “tamper location identification request mail”). The falsified image data is attached to the falsification location specifying request mail.

  On the other hand, when the image processing device PI receives the falsification location specifying request mail, the image processing device PI reads the reference image data to which the same file name is assigned for the falsified image data attached to the falsification location identification request mail. Are compared, the falsification location is specified, an e-mail notifying the specified falsification location is created, and a reply is sent to the transmission source of the falsification location specification request mail. For example, region information (coordinate information or the like) representing the falsification location in the falsified image data can be applied as the falsification location notification information.

  When such a reply mail is received, the data processing devices DT1 to DTn notify the user that the received image data has been tampered with, and display the specified tampered location according to the user's request.

  By doing in this way, it is possible to detect falsification and specify a falsification location for image data received or read by the data processing devices DT1 to DTn, which is very convenient.

  With the above configuration, when the user sets a read document on the scanner 5, the image processing apparatus PI performs an operation as shown in FIG.

  First, when the user sets a read document on the scanner 5 (process 101), the operation display unit 10 is appropriately operated until the user turns on a start key (not shown), and the reading conditions and the image format at the time of accumulation are displayed. (Image format) and the like are input (NO loop of processing 102 and determination 103).

  When the user turns on the start key and the result of determination 103 is YES, the scanner 5 is operated in accordance with the designated reading conditions to read the original image (processing 104), and the image data obtained by the reading is designated. The image data is converted into image data (process 105).

  Next, it is checked whether or not the setting for inserting an identifier is made when the image data is stored (decision 106). When the result of determination 106 is YES, a predetermined hash function operation is applied to the image data created in process 105 to calculate a hash value used as an identifier (process 107).

  Next, the identifier calculated in process 107 is inserted into the image data (process 108). At this time, when the identifier is inserted into the header information, the identifier is stored as comment information as described above. Further, when inserting as an electronic watermark, the identifier is directly inserted into the image data by applying a predetermined electronic watermark process.

  When the identifier is inserted into the image data in this way, the image data after the identifier is inserted is stored in the magnetic disk device 8 (process 109), and the operation at this time is terminated.

  6 and 7 show an example of processing when reading image data stored in the external medium MM.

  When reading of image data stored in the external storage medium MM is instructed by the user, it is checked whether the storage medium reading / writing device 12 detects the external storage medium MM (determination 201). When NO is displayed, a guidance message for prompting the user to set the external storage medium MM is displayed (process 202), and the process returns to decision 201.

  When the result of determination 201 is YES, the storage medium reading / writing device 12 acquires the file information stored in the external storage medium MM, creates file list information, and displays it on the operation display unit 10 ( Process 203), a file selection guidance message requesting selection of a file to be saved is displayed, and the user is allowed to select a file to be saved (NO in Process 204 and Decision 205).

  If the user finishes selecting one or more storage files and the result of determination 205 is YES, one is selected from the selected files (image data files) (processing 206), and the storage medium is read / written. The apparatus 12 reads the selected image data file from the external storage medium MM, and extracts the identifier as described above from the read image data file (process 207). In this identifier extraction process, first, it is checked whether or not an identifier is stored in the comment information of the header information, and if it is stored, the identifier is extracted. If the identifier is not stored in the comment information, it is checked whether or not the digital watermark data inserted into the image data can be extracted. If it is extracted, the identifier is reconstructed from the digital watermark data. If the digital watermark data cannot be extracted, it is determined that the identifier cannot be extracted from the image data.

  It is checked whether or not the identifier has been detected in the process 207 (determination 208). When the result of the determination 208 is YES, in order to detect whether or not the image file data selected at this time has been tampered with, the identifier collation process is first performed. (Processing 209). In this collation process, the hash value calculation is applied to the image data selected in the process 205 by applying the same hash function operation as that for creating the identifier, and the calculated hash value is compared with the identifier extracted in the process 207. To see if they match.

  It is checked whether or not the identifiers are confirmed to match in the identifier checking process of process 209 (determination 210). When the result of determination 210 is YES, it is set that an identifier is inserted when image data is saved. It is checked whether or not (decision 211).

  When the result of determination 211 is NO, the identifier is deleted from the image data file selected at that time (process 212). At this time, if the identifier is stored in the comment information of the header information, the identifier information is deleted from the comment information. If the digital watermark data is inserted into the image data, the digital watermark data is deleted. When the result of determination 211 is YES, processing 212 is not executed.

  Next, the image data is stored in the magnetic disk device 8 (process 213). If image data with the same file name has already been saved in the magnetic disk device 8 at the time of saving, the user is asked to confirm saving of the image data, and “change the file name of new image data” or The user selects “Save new image data over old image data” or “Do not save”, and performs the selected save operation.

  Then, it is checked whether or not the processing for all the image data files selected in the processing 204 has been completed (decision 214). If the result of the judgment 214 is NO, the processing returns to the processing 206 and another image data file is selected. Then, the subsequent processing is executed. If the result of determination 214 is YES, the operation at this time is terminated.

  In addition, when it is detected that the identifiers do not match in the identifier checking process of the process 209 and the result of the determination 210 is NO, there is a possibility that the image data has been falsified. Therefore, for example, a falsification detection guidance message such as “This image data has been falsified. The falsification location is displayed. Do you want to print it?” Is displayed on the operation display unit 10 (process 215). The user is notified that the image data has been tampered with.

  Next, image data having the same file name as the selected image data is read from the magnetic disk device 8, the selected image data is compared with the read image data, and the unmatched portion is extracted as a falsified portion, and is displayed on the operation display unit 10. Then, an image of a mode in which the extracted falsified portion is emphasized is displayed (processing 216).

  Here, when a print request is instructed by the user (the result of the determination 217 is YES), a recorded image in a form in which the falsified portion is highlighted is recorded and output (process 218). Further, when the result of determination 217 is NO, processing 218 is not executed.

  Then, the process proceeds to decision 214, and the subsequent processing is executed.

  If the identifier cannot be extracted from the image data selected in the process 206 and the result of determination 208 is NO, it is checked whether or not the setting for inserting the identifier is set when the image data is saved (decision 221). ). When the result of the determination 221 is YES, a predetermined hash function operation is applied to the selected image data to calculate a hash value used as an identifier (processing 222).

  Next, the identifier calculated in process 222 is inserted into the image data (process 223). At this time, when the identifier is inserted into the header information, the identifier is stored as comment information as described above. Further, when inserting as an electronic watermark, the identifier is directly inserted into the image data by applying a predetermined electronic watermark process.

  When the identifier is inserted into the image data in this way, the image data after the identifier is inserted is stored in the magnetic disk device 8 (process 224). Note that when the result of the determination 221 is NO, the processes 222 and 223 are not executed.

  Then, it is checked whether or not the processing has been completed for all the image data files selected in the processing 204 (decision 225). If the result of the judgment 225 is NO, the processing returns to the processing 206 to select another image data file. Then, the subsequent processing is executed. When the result of determination 225 is YES, the operation at this time is terminated.

  8 and 9 show an example of processing when the data processing device DX is connected to the image processing device PI and an image data file is transmitted from the data processing device DX.

  First, one or more image data files are received from the data processing device DX and temporarily stored (processing 301). Next, one is selected from the temporarily stored image data files (process 302), and the identifier as described above is extracted from the selected image data file (process 303). In this identifier extraction process, first, it is checked whether or not an identifier is stored in the comment information of the header information, and if it is stored, the identifier is extracted. If the identifier is not stored in the comment information, it is checked whether or not the digital watermark data inserted into the image data can be extracted. If it is extracted, the identifier is reconstructed from the digital watermark data. If the digital watermark data cannot be extracted, it is determined that the identifier cannot be extracted from the image data.

  It is checked whether or not the identifier has been detected in the process 303 (determination 304). If the result of the determination 304 is YES, in order to detect whether or not the image file data selected at this time has been tampered with, first the identifier verification process (Process 305). In this collation process, the hash value calculation is applied to the image data selected in the process 302 by applying the same hash function operation as that for creating the identifier, and the calculated hash value is compared with the identifier extracted in the process 303. To see if they match.

  It is checked whether or not the identifiers are confirmed to match in the identifier collation processing of processing 305 (determination 306). When the result of determination 306 is YES, it is set that the identifier is inserted when saving the image data. It is checked whether or not (Judgment 307).

  When the result of determination 307 is NO, the identifier is deleted from the image data file selected at that time (process 308). At this time, if the identifier is stored in the comment information of the header information, the identifier information is deleted from the comment information. If the digital watermark data is inserted into the image data, the digital watermark data is deleted. Further, when the result of determination 307 is YES, processing 308 is not executed.

  Next, the image data is stored in the magnetic disk device 8 (processing 309). If image data with the same file name has already been saved in the magnetic disk device 8 at the time of saving, the user is asked to confirm saving of the image data, and “change the file name of new image data” or The user selects “Save new image data over old image data” or “Do not save”, and performs the selected save operation.

  Then, it is checked whether or not the processing for all temporarily stored image data files has been completed (decision 310). When the result of determination 310 is NO, the processing returns to processing 302, and another image data file is selected, The subsequent processing is executed. If the result of determination 310 is YES, the operation at this time is terminated.

  In addition, when it is detected that the identifiers do not match in the identifier collation process of process 305, and the result of determination 306 is NO, there is a possibility that the image data has been falsified. Therefore, for example, a falsification detection guidance message such as “This image data has been falsified. The falsification location is displayed. Do you want to print it?” Is displayed on the operation display unit 10 (process 313). The user is notified that the image data has been tampered with.

  Next, image data having the same file name as the selected image data is read from the magnetic disk device 8, the selected image data is compared with the read image data, and the unmatched portion is extracted as a falsified portion, and is displayed on the operation display unit 10. Then, an image of a mode in which the extracted falsified portion is emphasized is displayed (processing 314).

  Here, when a print request is instructed by the user (the result of determination 315 is YES), a recorded image in a form in which the falsified portion is highlighted is recorded and output (processing 316). Further, when the result of determination 315 is NO, processing 316 is not executed.

  Then, the process proceeds to decision 310, and the subsequent processing is executed.

  If the identifier cannot be extracted from the image data selected in the process 303 and the result of determination 304 is NO, it is checked whether or not the setting for inserting the identifier is set when the image data is stored (determination 321). ). When the result of the determination 321 is YES, a predetermined hash function operation is applied to the selected image data to calculate a hash value used as an identifier (processing 322).

  Next, the identifier calculated in process 322 is inserted into the image data (process 323). At this time, when the identifier is inserted into the header information, the identifier is stored as comment information as described above. Further, when inserting as an electronic watermark, the identifier is directly inserted into the image data by applying a predetermined electronic watermark process.

  When the identifier is inserted into the image data in this way, the image data after the insertion of the identifier is stored in the magnetic disk device 8 (process 324). Note that when the result of the determination 321 is NO, the processes 322 and 323 are not executed.

  Then, it is checked whether or not the processing for all the temporarily stored image data files has been completed (decision 325). When the result of determination 325 is NO, the processing returns to processing 302, and another image data file is selected. The subsequent processing is executed. If the result of determination 325 is YES, the operation at this time is terminated.

  10, FIG. 11, and FIG. 12 show an example of processing performed by the image processing apparatus PI when an electronic mail is received.

  When the electronic mail is received (the result of determination 401 is YES), it is checked whether an image data file is attached to the received electronic mail (determination 402). When the result of determination 402 is NO, a process at the time of normal e-mail reception (process 403; for example, a process of recording and outputting the contents of the received e-mail) is performed, and the operation at this time is terminated.

  If the result of determination 402 is YES, one or more attached files are temporarily stored (process 404), and it is checked whether the received electronic mail is a storage request (determination 405). Here, when the image processing apparatus PI receives an e-mail to which image data is attached, the e-mail is an e-mail of a so-called storage request in which image data storage is requested by another terminal apparatus, or data processing. The device DT1 to DTn is any of the falsification location specifying request mail requesting specification of the falsification location. Further, for example, a storage request e-mail can be determined because a character string representing a storage request is arranged in the “Subject” field of the header information of the e-mail, such as “save request”. Further, for example, a character string indicating a falsification location specifying request, such as “falsification location specification request”, is arranged in the “Subject” field of the header information of the e-mail. can do.

  When the received e-mail is a save request e-mail and the result of determination 405 is YES, one is selected from the temporarily stored image data files (process 406), and the above-described image data file is selected from the selected image data file. Such an identifier is extracted (process 407). In this identifier extraction process, first, it is checked whether or not an identifier is stored in the comment information of the header information, and if it is stored, the identifier is extracted. If the identifier is not stored in the comment information, it is checked whether or not the digital watermark data inserted into the image data can be extracted. If it is extracted, the identifier is reconstructed from the digital watermark data. If the digital watermark data cannot be extracted, it is determined that the identifier cannot be extracted from the image data.

  It is checked whether or not the identifier has been detected in the process 407 (determination 408). If the result of the determination 408 is YES, in order to detect whether or not the image file data selected at this time has been tampered with, first the identifier verification process (Process 409). In this collation process, the hash value calculation is applied to the image data selected in process 406 by applying the same hash function operation as that at the time of creating the identifier, and the calculated hash value is compared with the identifier extracted in process 407. To see if they match.

  It is checked whether or not the identifiers are confirmed to match in the identifier collation processing of processing 409 (decision 410). When the result of determination 410 is YES, it is set that an identifier is inserted when image data is saved. It is checked whether or not (Judgment 411).

  When the result of determination 411 is NO, the identifier is deleted from the image data file selected at that time (process 412). At this time, if the identifier is stored in the comment information of the header information, the identifier information is deleted from the comment information. If the digital watermark data is inserted into the image data, the digital watermark data is deleted. Further, when the result of determination 411 is YES, processing 412 is not executed.

  Next, the image data is stored in the magnetic disk device 8 (process 413). If image data with the same file name has already been saved in the magnetic disk device 8 at the time of saving, the user is asked to confirm saving of the image data, and “change the file name of new image data” or The user selects “Save new image data over old image data” or “Do not save”, and performs the selected save operation.

  Then, it is checked whether or not the processing for all the temporarily stored image data files has been completed (decision 414). When the result of determination 414 is NO, the processing returns to processing 406 to select another image data file, The subsequent processing is executed. When the result of determination 414 is YES, the operation at this time is terminated.

  In addition, when it is detected that the identifiers do not match in the identifier collation process of process 409, and the result of determination 410 is NO, the image data may be falsified. Therefore, for example, a falsification detection guidance message such as “This image data has been falsified. The falsification location is displayed. Do you want to print it?” Is displayed on the operation display unit 10 (process 415). The user is notified that the image data has been tampered with.

  Next, image data having the same file name as the selected image data is read from the magnetic disk device 8, the selected image data is compared with the read image data, and the unmatched portion is extracted as a falsified portion, and is displayed on the operation display unit 10. Then, an image of a mode in which the extracted falsified portion is emphasized is displayed (processing 416).

  Here, when a print request is instructed by the user (the result of determination 417 is YES), a recorded image in a mode in which the falsified portion is highlighted is recorded and output (process 418). Further, when the result of determination 417 is NO, processing 418 is not executed.

  Then, the process proceeds to decision 414, and the subsequent processing is executed.

  Further, when the identifier cannot be extracted from the image data selected in the process 406 and the result of the determination 408 is NO, it is checked whether or not the setting for inserting the identifier is set when the image data is stored (determination 421). ). When the result of the determination 421 is YES, a predetermined hash function operation is applied to the selected image data, and a hash value used as an identifier is calculated (processing 422).

  Next, the identifier calculated in process 422 is inserted into the image data (process 423). At this time, when the identifier is inserted into the header information, the identifier is stored as comment information as described above. Further, when inserting as an electronic watermark, the identifier is directly inserted into the image data by applying a predetermined electronic watermark process.

  When the identifier is inserted into the image data in this way, the image data after the identifier is inserted is stored in the magnetic disk device 8 (process 424). When the result of determination 421 is NO, processes 422 and 423 are not executed.

  Then, it is checked whether or not the processing for all temporarily stored image data files has been completed (decision 425). When the result of determination 425 is NO, the processing returns to processing 406, and another image data file is selected. The subsequent processing is executed. If the result of determination 425 is YES, the operation at this time is terminated.

  If the received e-mail is not a save request e-mail but a falsification location specifying request e-mail and the result of determination 405 is NO, an identifier is extracted from the image data temporarily stored in process 404 (process 430). ). In this process 430, the same process as the process 407 is performed. And an identifier collation process is performed (process 431). In this process 431, the same process as the process 409 is performed.

  Here, when it is detected that the identifiers match in the identifier checking process of the process 431, and the result of the determination 432 is YES, for example, “This image data is not likely to be falsified”. An e-mail that has a simple body message and is sent back to the transmission source e-mail address of the falsification location specifying request e-mail is generated (process 433), and the generated e-mail is transmitted (process 434).

  Further, when it is detected that the identifiers do not match in the identifier checking process of the processing process 431 and the result of the determination 432 is NO, the image data may be falsified. Therefore, first, image data having the same file name as the temporarily stored image data is read from the magnetic disk device 8, the temporarily stored image data is compared with the read image data, and a portion that does not match is extracted as a falsified portion. Falsified part information representing the part is created (process 435).

  Next, an e-mail that includes the altered part information created in process 435 in the body message and is sent back to the e-mail address of the falsification location specifying request mail is created (process 436), and the process proceeds to process 434. Send.

  FIG. 13 shows an example of processing when the image processing apparatus PI transmits an e-mail.

  First, the user edits email transmission information (step 501). In this editing operation, designation of a destination, designation of whether or not an image data file stored in the magnetic disk device 8 is attached, and the like are performed.

  Next, it is checked whether or not the attachment of the image data file is specified in the e-mail to be transmitted (determination 502). If the result of determination 502 is YES, is it set to insert an identifier when saving the image data? A check is made (decision 503).

  When the result of determination 106 is NO, each image data designated to be attached is read from the magnetic disk device 8, a predetermined hash function operation is applied to each read image data, and a hash value used as an identifier And the calculated identifier is inserted into the image data (process 504). At this time, when the identifier is inserted into the header information, the identifier is stored as comment information as described above. Further, when inserting as an electronic watermark, the identifier is directly inserted into the image data by applying a predetermined electronic watermark process.

  Next, each image data with the identifier inserted created in process 504 is arranged in the body information as an attached file (process 505). At this time, the attached file is converted as data in MIME format and arranged in the text information.

  Next, the specified destination e-mail address is set in the “To” field, the e-mail address of the terminal or user is set in the “From” field, and the specified character string is set in the “Subject” field. Header information having various fields is created (process 506).

  Then, an electronic mail composed of the created text information and header information is transmitted (process 507), and the operation at this time is terminated.

  When the result of determination 503 is YES, an identifier has already been inserted into the image data stored in the magnetic disk device 8. Therefore, in this case, each image data designated to be attached is arranged in the text information as an attached file (processing 508). At this time, the attached file is converted as data in MIME format and arranged in the text information. Then, the process proceeds to processing 506, and after creating header information, an e-mail made up of body information and header information created at that time is transmitted.

  On the other hand, if attachment of an image data file is not specified and the result of determination 502 is NO, predetermined header information is created (process 509), body information is created (process 510), and the process proceeds to process 507. Go ahead and send an e-mail consisting of the created header information and body information.

  FIG. 14 shows an example of processing performed when the data processing devices DT1 to DTn receive an email.

  When the electronic mail is received (the result of determination 601 is YES), it is checked whether an image data file is attached to the received electronic mail (determination 602). When the result of determination 602 is NO, processing at the time of normal e-mail reception (processing 603; for example, processing for notifying the user of e-mail reception) is performed, and the operation at this time is terminated.

  If the result of determination 602 is YES, one or more attached files are temporarily saved (process 604). Next, one of the temporarily stored image data files is selected (process 605), and the identifier as described above is extracted from the selected image data file (process 606). In this identifier extraction process, first, it is checked whether or not an identifier is stored in the comment information of the header information, and if it is stored, the identifier is extracted. If the identifier is not stored in the comment information, it is checked whether or not the digital watermark data inserted into the image data can be extracted. If it is extracted, the identifier is reconstructed from the digital watermark data. If the digital watermark data cannot be extracted, it is determined that the identifier cannot be extracted from the image data.

  It is checked whether or not the identifier has been detected in the process 606 (determination 607). If the result of the determination 607 is YES, in order to detect whether or not the image file data selected at this time has been tampered with, first the identifier verification process (Process 608). In this collation process, the hash value calculation is applied to the image data selected in the process 406 by applying the same hash function operation as that for creating the identifier, and the calculated hash value is compared with the identifier extracted in the process 606. To see if they match.

  It is checked whether or not the identifiers are confirmed to match in the identifier collating process of process 608 (determination 609). When the result of determination 609 is YES, a predetermined attached file process (process 610) is performed. In the attached file processing, processing such as saving the attached image data file in a predetermined area is performed.

  Then, it is checked whether or not the processing for all the temporarily stored image data files has been completed (decision 611). When the result of judgment 611 is NO, the processing returns to processing 605 to select another image data file, The subsequent processing is executed. When the result of determination 611 is YES, the operation at this time is terminated.

  Further, when it is detected that the identifiers do not match in the identifier collating process in the process 608, and the result of the determination 609 is NO, the image data may be falsified. Therefore, a falsification location identification request mail is created and transmitted (process 612). The header information of the falsification location specifying request mail includes the email address of the image processing device PI in the “To” field, the email address of the terminal or user in the “From” field, and the “falsification location identification” in the “Subject” field. A character string “request” is set, and other necessary fields are included. Further, the text information of the falsification location identification request mail is the image data file selected in the process 605 converted to MIME and attached as an attached file.

  Then, a reply mail from the image processing device PI is received (processing 613). The reply mail received at this time includes the falsified portion information indicating the falsified portion as described above. Therefore, for example, an alteration detection guidance message such as “The image data attached to the received e-mail has been altered. Do you want to display the alteration location?” Is displayed on the CRT screen display device 31. (Process 615) The user is notified that the image data has been tampered with.

  Here, when a display request is instructed by the user (the result of determination 615 is YES), an image in a form in which the altered portion is highlighted is displayed and output on the CRT screen display device 31 (process 616). Further, when the result of determination 615 is NO, processing 616 is not executed.

  Then, the process proceeds to decision 611, and the subsequent processing is executed.

  In the embodiment described above, electronic data (image data) is applied as a processing target for falsification detection. However, the present invention can be similarly applied to falsification detection of paper information.

  In that case, the identifier is inserted into the image data obtained by reading the original image. For example, as shown in FIG. 15, the read image data is divided into a predetermined number of blocks BLK, and each block is divided into a digital watermark. A method of inserting as digital watermark data using technology can be employed.

  Further, when the read image data with the identifier inserted in this way is recorded and output, a recorded document with an electronic watermark inserted is obtained.

  The read image data obtained by reading the recorded document with the digital watermark inserted by the scanner 5 includes a digital watermark data element. The data element of the digital watermark can be extracted by a well-known method. The inserted identifier can be reconstructed based on the extracted digital watermark data element.

  FIGS. 16 and 17 show an example of processing performed by the image processing apparatus PI at the time of document reading in this case.

  First, when the user sets a read document on the scanner 5 (process 701), the operation display unit 10 is appropriately operated until the user turns on a start key (not shown) to read the reading conditions and the image format at the time of storage. (Image format) and the like are input (NO loop of processing 702 and determination 703).

  When the user turns on the start key and the result of determination 703 is YES, the scanner 5 is operated in accordance with the designated reading conditions to read the original image (processing 704). An identifier extraction process is performed (process 705). In this identifier extraction process, the data element of the digital watermark included in the image data read in process 704 is extracted by a known method, and the inserted identifier is reconstructed based on the extracted digital watermark data element. Can do.

  Next, it is checked whether or not the identifier has been detected in the identifier extraction processing in step 705 (decision 706). When the result of determination 706 is YES, identifier collation processing is performed (processing 707). In this identifier collation process, the digital watermark data element is removed from the image data, and a predetermined hash function operation is applied to the image data after the removal to calculate a hash value. Then, it is checked whether or not the identifier extracted in process 705 matches the calculated hash value.

  It is checked whether or not the identifiers are confirmed to match in the identifier collating process of process 707 (determination 708). When the result of determination 708 is YES, it is set that the identifier is inserted when saving the image data. It is checked whether or not (decision 709).

  When the result of determination 709 is NO, the digital watermark data element is deleted from the image data (process 709), and the image data is converted into image data of the designated image format (process 710).

  Next, it is checked whether or not the setting for inserting an identifier is made when the image data is stored (decision 711). When the result of determination 711 is YES, a predetermined hash function operation is applied to the image data created in process 710 to calculate a hash value used as an identifier (process 712).

  Next, the identifier calculated in process 712 is inserted into the image data (process 713). At this time, as described above, the image data is divided into a plurality of blocks, and an identifier is inserted as digital watermark data in units of blocks.

  When the identifier is inserted into the image data in this way, the image data after the identifier is inserted is stored in the magnetic disk device 8 (process 714), and the operation at this time is terminated.

  Further, when it is detected that the identifiers do not match in the identifier collating process of the process 707 and the result of the determination 708 is NO, the image data may be falsified. Therefore, for example, an operation display section displays a falsification detection guidance message such as “This image data has been falsified. If you enter the file name of the image data, the falsification location will be displayed. Do you want to print it?” 10 (process 715), the user is notified that the image data has been tampered with, and requests input of a file name.

  Next, the input image data of the file name is read from the magnetic disk device 8, the read image data is compared with the read image data, a non-matching portion is extracted as a falsified portion, and the extracted falsification is displayed on the operation display unit 10. The image of the aspect which emphasizes a part is displayed (process 716).

  Here, when a print request is instructed by the user (the result of determination 717 is YES), a recorded image in a form in which the falsified portion is highlighted is recorded (process 718), and this process ends. Further, when the result of determination 717 is NO, processing 718 is not executed.

  If the identifier cannot be extracted from the image data selected in process 705 and the result of determination 706 is NO, the data is converted into image data of the designated image format (process 720).

  Next, it is checked whether or not the setting for inserting an identifier is made when the image data is stored (decision 721). When the result of determination 721 is YES, a predetermined hash function operation is applied to the image data created in process 720 to calculate a hash value used as an identifier (process 722).

  Next, the identifier calculated in process 722 is inserted into the image data (process 723). At this time, as described above, the image data is divided into a plurality of blocks, and an identifier is inserted as digital watermark data in units of blocks.

  When the identifier is inserted into the image data in this way, the image data after the identifier is inserted is stored in the magnetic disk device 8 (process 724), and the operation at this time is terminated. If the result of determination 721 is NO, processing 722 and 723 are not executed and processing proceeds to processing 724 where image data is saved and processing ends.

  In the above-described embodiment, the case where the present invention is applied to an image processing apparatus connected to a network has been described. However, the present invention can be applied to other image processing apparatuses in the same manner.

The block diagram which showed an example of the network system concerning one Example of this invention. The block diagram which showed the structural example of image processing apparatus PI. The block diagram which showed the structural example of data processor DT (DT1-DTn). Schematic which showed an example of the image data storage format. 6 is a flowchart illustrating an example of processing performed by the image processing apparatus PI when reading a document. Flowchart showing an example of processing when reading image data stored in the external medium MM (continued). 7 is a flowchart illustrating an example of processing when image data stored in an external medium MM is read (continuation of FIG. 6). Flowchart showing an example of processing when the data processing device DX is connected to the image processing device PI and an image data file is transmitted from the data processing device DX (continued). 9 is a flowchart illustrating an example of processing when the data processing device DX is connected to the image processing device PI and an image data file is transmitted from the data processing device DX (continuation of FIG. 8). The flowchart which showed an example of the process which image processing apparatus PI performs when an electronic mail is received (continuation). 11 is a flowchart illustrating an example of processing performed by the image processing apparatus PI when an e-mail is received (continuation of FIG. 10). 12 is a flowchart illustrating an example of processing performed by the image processing apparatus PI when an e-mail is received (continuation of FIG. 11). The flowchart which showed an example of the process at the time of image processing apparatus PI transmitting an email. The flowchart which showed an example of the process performed when data processor DT1-DTn receives an email. Schematic for demonstrating the other example of the insertion aspect of an identifier. Flowchart showing an example of processing performed by the image processing apparatus PI during document reading (continued). 18 is a flowchart (continuation of FIG. 16) illustrating an example of processing performed by the image processing apparatus PI during document reading.

Explanation of symbols

PI image processing device DX data processing device MM external storage medium 1 system control unit 2 system memory 3 parameter memory 8 magnetic disk device 9 image processing unit 11 external interface circuit 12 storage medium read / write device 13 media interface circuit 14 local area network interface Circuit 15 Local Area Network Transmission Control Unit

Claims (15)

In an image processing apparatus having an image storage management function for storing and managing a large number of image data,
While performing a predetermined function calculation based on the content of the image data, calculating an identifier having a value uniquely determined by the content of the image data, and using the identifier for detecting falsification of the image data to be stored and managed,
For altered image data that has been confirmed to be falsified, the image data stored in the image storage management function is compared with the altered image data to identify the alteration location of the altered image data. A featured image processing apparatus.   The image processing apparatus according to claim 1, wherein the predetermined function calculation is a hash function calculation, and the identifier is a hash value obtained as a result of the hash function calculation.   The image processing apparatus according to claim 1, wherein the identifier is inserted into the output image data.   The image processing apparatus according to claim 1, wherein the identifier is inserted into a header area of the output image data.   The image processing apparatus according to claim 1, wherein the identifier is inserted as a digital watermark in a data area of the output image data.   6. The image processing apparatus according to claim 3, wherein the identifier is inserted into the image data when the image data is stored by the image storage management function.   6. The image processing apparatus according to claim 3, wherein the identifier is inserted into the image data when the image data is output to the outside by the image storage management function. . Further equipped with a document reading function,
When image data obtained by reading an image of a read original using the original reading function is stored by the image accumulation management function, the identifier is calculated for the image data, and the identifier is inserted into the image data. 6. The image processing apparatus according to claim 3, 4 or 5. Further equipped with an interface function with external devices,
When the image data received in response to the storage request from the external device via the interface function is stored by the image storage management function, the identifier is calculated for the image data, and the identifier is inserted into the image data. The image processing apparatus according to claim 3, claim 4, claim 5, or claim 8. A communication function for connecting to a network and communicating with other devices via the network;
The image data received via the communication function is saved, and when the received image data is saved by the image storage management function, the identifier is calculated for the image data, and the identifier is inserted into the image data. The image processing apparatus according to claim 3, claim 4, claim 5, claim 8, or claim 9. It further includes an e-mail communication function for connecting to a network and exchanging information with other devices using e-mail via the network.
The image data attached to the e-mail received via the e-mail communication function is saved, and the identifier is calculated for the image data when the received image data is saved by the image accumulation management function. 11. The image processing apparatus according to claim 3, wherein the identifier is inserted into the image data.   When the identifier is inserted in the image data stored by the image accumulation management function, the inspection identifier is calculated for the image data by executing the predetermined function calculation, and the calculated inspection The falsification of the image data is detected by comparing the identifier of the image and the inserted identifier. The claim 1, the claim 2, the claim 3, the claim 4, or the claim 5 The image processing apparatus according to claim 6, claim 7, claim 8, claim 9, claim 10, or claim 11.   13. The image processing apparatus according to claim 12, wherein when alteration of the image data is detected, a message to that effect is displayed to the user. When tampering with the image data is detected, a message to that effect is displayed to the user,
13. The image processing apparatus according to claim 12, wherein a falsified portion of the falsified image data in which the falsification is detected is displayed.   15. The image processing apparatus according to claim 13, wherein when the alteration of the image data is detected, the alteration location of the image data to be altered in which the alteration is detected is recorded and output.

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