JP4027371B2 - Printing device - Google Patents

Description

  The present invention relates to a printing apparatus that prints an image on a printing medium such as paper, such as a printer, a copying machine, a facsimile machine, or a multifunction machine that combines a printer and another apparatus.

  In recent years, in order to detect fraudulent acts such as duplication and falsification of an image printed on a print medium (hereinafter referred to as a print image), and to trace later print acts, it is referred to as digital watermark. A technique has been developed in which invisible data is embedded in print image data (hereinafter referred to as print image data) and printed.

  As this main conventional technique, for example, there is a technique using a printing apparatus and a host apparatus that outputs a print command to the printing apparatus as described below (see Patent Document 1).

  That is, a higher-level device (such as a personal computer or a server) of the printing device generates a digital watermark and embeds the digital watermark in the print image data. Then, the host device outputs print image data in which the digital watermark is embedded (hereinafter referred to as watermarked print image data) and the digital watermark embedded in the watermarked print image data to the printing device. The printing apparatus includes a print processing unit, a storage unit, and a document reading unit (hereinafter referred to as a printing unit, a data storage unit, and a reading unit, respectively). Upon acquisition, based on the watermarked print image data, a print image embedded with a digital watermark (hereinafter referred to as a watermarked print image) is printed on a print medium by the printing unit, and the watermarked print image data and the digital watermark are The data is stored in the data storage unit in association with each other. Then, when the printing device reads the print medium on which the watermarked print image is printed at a later time, the printing apparatus extracts the digital watermark embedded in the watermarked print image printed on the print medium, and the digital watermark Is read from the data storage unit and reprinted on the print medium.

  This conventional technique can print a print image in which invisible data called a digital watermark is embedded on a print medium. This conventional technique can also reprint print image data (hereinafter referred to as original print image data) stored in the data storage unit of the printing apparatus.

Note that generation of a digital watermark and embedding of a digital watermark in print image data are disclosed in JP 2003-101762 A, JP 2003-209676 A, and others, but detailed description thereof is omitted here. (See Patent Documents 2 and 3).
JP 2003-134325 A (6th to 19th paragraphs, FIGS. 1 to 6) JP 2003-101762 A JP 2003-209676 A

  The conventional technique has a problem that a print image in which an electronic watermark is not embedded may be printed, and the security of the print image printed on the print medium may be lowered.

  That is, in the prior art, the host device generates a digital watermark and embeds the digital watermark in print image data. Therefore, in the conventional technology, when the host device does not generate the digital watermark or embed the digital watermark in the print image data, the printing device prints the print image without the digital watermark embedded on the print medium. . In this case, the printer (or the administrator of the printer) cannot obtain data for tracking the occurrence of printing activities such as when, where, and where printing was performed (hereinafter referred to as tracking data). So it was not possible to track the occurrence of printing act. As a result, in the conventional technique, the security of the print image printed on the print medium may be lowered.

  Further, the conventional technique has a problem that it places a great burden on the printer.

  That is, in the prior art, software for embedding a digital watermark in print image data (hereinafter referred to as embedded software) has been stored in the host device. Moreover, the embedded software needs to be operated manually by the printer, and the data (hereinafter referred to as tracking data) that enables the printing activity to be traced as a digital watermark for each printing medium. It has been necessary to manually perform settings for embedding in a print image and settings of a printing apparatus for appropriately printing a digital watermark. For this reason, the conventional technique places a great burden on the printer as compared with normal printing without embedding a digital watermark.

  A printing apparatus according to the present invention includes a data acquisition unit that acquires print data for printing an image on a print medium from the outside, and printing that is image data of a print image based on the print data acquired by the data acquisition unit Embedded in the print image as a digital watermark based on the print image forming unit that forms the image data, the print data acquired by the data acquisition unit and the device data that is data specific to the printing device or the printing situation, An embedded data generation unit that generates embedded data, a copy-forgery-inhibited pattern image forming unit that forms copy-forgery-inhibited pattern image data that is image data of a digital watermark copy-forgery-inhibited pattern image based on the embedded data generated by the embedded data generation unit, and print image formation Image data formed by the print area and copy-forgery-inhibited pattern image data formed by the copy-forgery-inhibited pattern image formation section Are combined to form a composite image data that is the image data of a watermarked print image in which the digital watermark is embedded, and the digital watermark is embedded based on the composite image data formed by the image composite unit. And a printing unit that prints a composite image, which is a watermarked print image, on a print medium.

  Note that “printing apparatus” means all devices having a printing function, and includes, for example, a printer, a copier, a facsimile machine, a multi-function machine that combines a printer and another apparatus, and the like. The “external” is a higher-level device (for example, a personal computer or a server) or a memory medium (for example, a memory card, DVD, CD-ROM, portable memory device, portable HDD device, or the like). . “Print data” is data for printing an image of a document or a figure (including a photograph, a picture, a table, etc.) on a print medium. “Print data” is, for example, print image data, text data in the print image, print data name, page description language such as postscript, copyright data of the print image (for example, copyright name, copyright number, copyright The right group), data for detecting falsification of the print image (for example, data obtained by reducing the print image), and other groups of candidate data that are candidates for data embedded in the print image (embedded data) as a digital watermark It consists of one or more types of data. In particular, in the present invention, the “print data” preferably includes at least one of copyright data and falsification detection data of a print image. “Print data” is stored in the host device or the memory medium. “Apparatus data” is data relating to the printing apparatus or the status at the time of printing. The device data includes, for example, the ID of the printing device (i.e., a code or name unique to the printing device), the printing date and time, the printing department (i.e., the code or name of the printing department), and the printer (i.e., the printer code or name). Name), print gradation (that is, print density), print resolution, print medium size, and other candidate data groups that are candidates for data (embedded data) embedded in a print image as a digital watermark Or consisting of multiple types of data. The “apparatus data” is stored inside the printing apparatus or the upper apparatus.

The printing apparatus according to the present invention always generates and embeds a digital watermark based on the print data and data unique to the printing apparatus or the printing situation (hereinafter referred to as apparatus data). For this reason, the printer (or the administrator of the printer) can always obtain the tracking data such as when and where the user has printed from the print medium, and can always track the occurrence of the printing action. .
In addition to the above-described components of the printing apparatus according to the present invention, the printing apparatus described in claim 1 further reads the composite image data from the print medium and acquires the read data that is the result of reading the composite image data. A reading unit, a watermark data extraction unit that extracts the copy-forgery-inhibited pattern image data from the read data acquired by the reading unit, and obtains watermark data that is the extraction result of the copy-forgery-inhibited pattern image data, and an embedding generated by the embedded data generation unit By comparing the data and the embedded data included in the watermark data extracted by the watermark data extraction unit, and determining whether they match within a predetermined tolerance, the print image is printed correctly on the print medium. An extraction result determination unit that determines whether or not the data is included, and the extraction result determination unit is included in the embedded data and the watermark data When the embedded data matches within a predetermined allowable range, it is determined that the composite image is correctly printed on the print medium, and the watermark data is output to a host device that outputs a print command to the printing device. When the embedded data and the embedded data included in the watermark data do not match within a predetermined allowable range, it is determined that the composite image is not correctly printed on the print medium, and the error data and the watermark data are output to the host device. It is characterized by that.
According to another aspect of the present invention, when the data acquisition unit acquires the document data as the print data, the print image forming unit reads the document data from the extension attached to the file name of the document data. It recognizes the file format and forms print image data based on the recognized file format.
According to a third aspect of the present invention, when the data acquisition unit acquires document data to which a designated address for specifying a file format is attached as print data, the print image forming unit receives the document data The designated address data attached to is recognized, and based on the recognized designated address data, the file format of the document data is obtained from the internal data storage unit of the printing apparatus, and the print image data is obtained based on the obtained file format. It is characterized by forming.
The printing apparatus according to claim 4, wherein the copy-forgery-inhibited pattern image forming unit has a 0-bit value based on the embedded data so that the size is the same as the size of the print image data formed by the print image forming unit. By forming invisible embedded pixel data defined as an array pattern meaning an array pattern and invisible embedded pixel data defined as an array pattern meaning a 1-bit value, image data that forms the basis of the tint block image data is formed. Then, the copy-forgery-inhibited pattern image data is formed by applying the base image data to the reduced print image data formed by reducing the print image data so that the print image data can be embedded as a digital watermark. It is characterized by.
According to a fifth aspect of the present invention, there is provided a printing apparatus including a data acquisition unit that acquires print data for printing an image on a print medium from an external device, and a host apparatus that outputs a print command to the printing apparatus using the data acquisition unit. When compressed data combining a plurality of types of data is acquired, the compressed data is decompressed, and print data and copy-forgery-inhibited pattern data obtained by encoding copy-forgery-inhibited pattern image data that is image data of a digital watermark copy-forgery-inhibited pattern image are obtained. A compressed data decompression unit to be acquired; a print image forming unit that forms print image data that is image data of a print image based on the print data obtained by the compressed data decompression unit; and a copy-forgery-inhibited pattern obtained by the compressed data decompression unit A copy-forgery-inhibited pattern image forming unit that forms copy-forgery-inhibited pattern image data based on the encoded data, and print image data formed by the print image forming unit Formed by the image composition unit and an image composition unit that composes the copy-forgery-inhibited pattern image data formed by the pattern image formation unit and forms composite image data that is image data of a watermarked print image embedded with a digital watermark And a printing unit that prints a composite image, which is a watermarked print image embedded with a digital watermark, on a print medium based on the composite image data.
According to a sixth aspect of the present invention, in the printing apparatus according to the fifth aspect, the compressed data acquired from the host device is obtained by reversibly compressing a plurality of types of data by the Run-Length method or the Huffman method. It is generated.
In addition to the above-described components of the printing apparatus according to the present invention, the printing apparatus according to any one of claims 7, 9, 11, and 13 may be combined before the printing unit performs a printing process based on the combined image data. A watermark pre-verification unit is provided for verifying whether or not the image data is fraudulent.
In the printing apparatus according to claim 7, the watermark pre-verification unit includes the embedded data embedded in the print image as the electronic watermark from the host apparatus that outputs the print command to the printing apparatus, and the embedding process. When compressed data that is generated based on data and is the basis of composite image data and that combines multiple types of data is extracted, embedded data is extracted from the compressed data, and the extracted embedded data The embedded data acquired from the apparatus is compared, and when both do not match within a predetermined allowable range, it is determined that there is an illegal act on the composite image data.
In the printing apparatus according to claim 9, the watermark pre-verification unit includes the embedded data embedded in the print image as a digital watermark from the host apparatus that outputs the print command to the printing apparatus, and the embedding process. When the composite image data generated based on the data is acquired, the embedded data is extracted from the composite image data, and the extracted embedded data is compared with the embedded data acquired from the host device. When there is no match within the range, it is determined that there has been an illegal act on the composite image data.
In the printing apparatus according to claim 11, the watermark pre-verification unit receives, as an electronic watermark, print image data that is image data of a print image from a higher-level apparatus that outputs a print command to the printing apparatus. The copy-forgery-inhibited pattern encoded data obtained by encoding the copy-forgery-inhibited pattern image data based on the reduced print image data based on the reduced print image data and the composite image data formed by reducing the data to be less than the embeddable data amount When the compressed data in which a plurality of types of data is combined is extracted, the ground pattern encoded data is extracted from the compressed data, and the reduced print image data is extracted from the ground pattern encoded data, and the extracted reduction is performed. The brightness value of the print image data is compared with the brightness value of the reduced print image data acquired from the host device, and the difference between the two is a predetermined threshold value. When is large in Ri, and judging that the unauthorized action against the composite image data.
In the printing apparatus according to claim 13, the watermark pre-verification unit receives the reduced print image data and the copy-forgery-inhibited pattern based on the reduced print image data from the host apparatus that outputs the print command to the print apparatus. When the composite image data generated based on the image data is acquired, the reduced print image data is extracted from the composite image data, and the brightness value of the extracted reduced print image data and the reduced print image data acquired from the host device are acquired. When the difference between the two is larger than a predetermined threshold value, it is determined that there is an illegal act on the composite image data.
In addition to the components of the printing apparatus according to claim 5, the printing apparatus according to claim 8, 10, 12, and 14 is further configured to perform printing processing based on the composite image data by the printing unit. And a watermark pre-verification unit for verifying whether or not there is an illegal act on the composite image data.
In the printing apparatus according to claim 8, the watermark pre-verification unit includes the embedded data embedded in the print image as a digital watermark from the higher-level apparatus that outputs the print command to the printing apparatus, and the embedding process. When compressed data that is generated based on data and is the basis of composite image data and that combines multiple types of data is extracted, embedded data is extracted from the compressed data, and the extracted embedded data The embedded data acquired from the apparatus is compared, and when both do not match within a predetermined allowable range, it is determined that there is an illegal act on the composite image data.
In the printing apparatus according to claim 10, the watermark pre-verification unit includes the embedded data embedded in the print image as a digital watermark from the host apparatus that outputs a print command to the printing apparatus, and the embedding process. When the composite image data generated based on the data is acquired, the embedded data is extracted from the composite image data, and the extracted embedded data is compared with the embedded data acquired from the host device. When there is no match within the range, it is determined that there has been an illegal act on the composite image data.
In the printing apparatus according to claim 12, the watermark pre-verification unit receives, as an electronic watermark, print image data that is image data of a print image from a higher-level apparatus that outputs a print command to the printing apparatus. The copy-forgery-inhibited pattern encoded data obtained by encoding the copy-forgery-inhibited pattern image data based on the reduced print image data based on the reduced print image data and the composite image data formed by reducing the data to be less than the embeddable data amount When the compressed data in which a plurality of types of data is combined is extracted, the ground pattern encoded data is extracted from the compressed data, and the reduced print image data is extracted from the ground pattern encoded data, and the extracted reduction is performed. The brightness value of the print image data is compared with the brightness value of the reduced print image data acquired from the host device, and the difference between the two is a predetermined threshold value. When is large in Ri, and judging that the unauthorized action against the composite image data.
In the printing apparatus according to claim 14, the watermark pre-verification unit receives the reduced print image data and the copy-forgery-inhibited pattern based on the reduced print image data from the host apparatus that outputs the print command to the print apparatus. When the composite image data generated based on the image data is acquired, the reduced print image data is extracted from the composite image data, and the brightness value of the extracted reduced print image data and the reduced print image data acquired from the host device are acquired. When the difference between the two is larger than a predetermined threshold value, it is determined that there is an illegal act on the composite image data.

The printing apparatus according to the present invention can prevent printing of a print image in which a digital watermark is not embedded. For this reason, the printing person (or the administrator of the printing person) can always obtain the tracking data of the occurrence of the printing action such as when and who printed it from the print image, so that the printing action always occurs. Can be tracked. As a result, the present invention can eliminate the case where the security of the print image printed on the print medium is lowered.

In addition, the printer does not need to manually operate the embedding software, and the setting for embedding the tracking data in the print image manually for each print medium and the printing apparatus for appropriately printing the digital watermark There is no need to make any settings. As a result, the present invention can also reduce the burden on the printer.
According to the printing apparatus of claim 1, when the embedded data and the embedded data included in the watermark data match within a predetermined allowable range, the watermark data is output to the upper apparatus, and the embedded data and the watermark are output. When the embedded data included in the data does not match within a predetermined allowable range, the error data and the watermark data are output to the host device. As a result, the host device displays error display and tracking data, original print image data, and the like on the display, and prompts the printer to confirm them. The printer (or the administrator of the printer) can detect fraudulent acts such as copying or falsification of the printed image by browsing the screen displayed on the display and checking the data displayed on the screen. it can. In particular, when tampering is detected, the printer (or the administrator of the printer) can display the tampered location on the display and confirm the details of tampering in detail.
According to the second aspect of the present invention, when document data is acquired as print data, the file format of the document data is recognized from the extension attached to the file name of the document data, and the recognized file is recognized. Print image data can be formed based on the format.
According to a third aspect of the present invention, when document data with a designated address for specifying a file format is acquired as print data, the designated address data attached to the document data is recognized. Then, the file format of the document data can be acquired from the data storage unit inside the printing apparatus based on the recognized designated address data, and the print image data can be formed based on the acquired file format.
Further, according to the printing apparatus of claim 4, based on the embedded data, image data serving as a base of the copy-forgery-inhibited pattern image data is formed, and the image data serving as the base is applied to the reduced print image data, The tint block image data can be formed.
Further, according to the printing apparatus of the fifth aspect, when the compressed data obtained by combining a plurality of types of data is acquired from the host apparatus, the compressed data is decompressed, and the print data and the tint block encoded data are obtained. Acquire, form print image data based on the acquired print data, form copy-forgery-inhibited pattern image data based on the acquired copy-forgery-inhibited pattern data, and synthesize the formed print image data and copy-forgery-inhibited pattern image data Thus, the composite image data can be formed, and the composite image can be printed on the print medium based on the formed composite image data. As a result, the host device can output data (compressed data) for printing the watermarked print image to the printing device with a small amount of data. As a result, the host device can output data for printing the watermarked print image to the printing device in a short time, and can obtain an effect that the printing device can efficiently print the print image. .
According to the printing apparatus of the sixth aspect, the compressed data obtained from the host apparatus is generated by reversibly compressing a plurality of types of data by the Run-Length method or the Huffman method. Therefore, the higher-level device can output data for generating a print image embedded with a digital watermark to the printing device with a small amount of data by outputting the compressed data to the printing device.
Further, according to each of the printing apparatuses according to any one of claims 7 to 14, since the presence / absence of fraud is verified before the printing process, data for printing a watermarked print image from a remote location ( Even when compressed data or composite image data) is acquired, it is possible to obtain an effect that printing of a watermarked print image subjected to an illegal act such as tampering can be prevented. Further, according to the printing apparatus, since the fraud is detected at an early stage, it is possible to omit a useless process when the fraud is detected, and to improve the processing speed when the fraud is detected. it can.

  The present invention is characterized in that the printing device or its higher-level device generates a digital watermark based on the print data and data unique to the printing device or the printing situation (hereinafter referred to as device data). The generated digital watermark is embedded in the print image. The printing apparatus prints a print image in which the digital watermark is embedded (hereinafter referred to as a watermarked print image) on a print medium such as paper, and also extracts a digital watermark from the printed watermarked print image to the host apparatus. Output. As a result, the host device stores the digital watermark extracted from the printed watermarked print image.

  Note that the printing device means all devices having a printing function, and includes, for example, a printer, a copier, a facsimile machine, and a multifunction machine in which a printer and other devices are combined.

  The host device is an arithmetic processing device that outputs a print command to the printing device, such as a personal computer (hereinafter referred to as a PC) or a server.

  The print data is data for printing an image of a document or a graphic (including a photograph, a picture, a table, etc.) on a print medium. The print data includes, for example, print image data in a specific format, text data in the print image, name of the print data, page description language such as postscript, copyright data of the print image (for example, copyright name, copyright number, A group of candidate data that can be candidates for embedded data (embedded data) as digital watermarks, such as copyright holders, print image falsification detection data (for example, reduced print image data) It consists of one or more types of data. In particular, in this embodiment, the print data preferably includes at least one of copyright data of the print image and data for falsification detection. The print data is stored in the upper apparatus or in the memory medium.

  The device data is data unique to the printing device or the printing situation. The device data includes, for example, a printing device ID (ie, a code or name unique to the printing device), a printing date and time, a printing department (ie, a printing department code or name), and a printer (ie, a printer code or name). ), Print gradation (that is, print density), print resolution, print medium size, etc., one of the groups of candidate data that are candidates for data (embedded data) to be embedded in a print image as a digital watermark Consists of multiple types of data. The device data is stored in the printing device or in the host device.

  The print data and the device data are recorded as tracking data (that is, the occurrence of a printing act) by the embedded data generation unit 203 (described later) from any one of a group of candidate data that are candidates for embedded data. Is used for generating embedded data to be described later, which is embedded in a print image as a digital watermark.

  Embodiments of the present invention will be described below with reference to the drawings. Each figure is shown only schematically to the extent that the present invention can be understood. Therefore, the present invention is not limited to the illustrated example. Moreover, in each figure, the same code | symbol is attached | subjected about the common component and the same component, and those overlapping description is abbreviate | omitted.

  For generation of a digital watermark and embedding of a digital watermark in a printed image, techniques disclosed in Japanese Patent Laid-Open Nos. 2003-101762, 2003-209676, and others are used. (See Patent Documents 2 and 3).

  The first embodiment is characterized in that a printing apparatus, which is a terminal apparatus, automatically embeds a digital watermark into all print images. According to this embodiment, the printer can print the watermarked print image on the print medium without being conscious of embedding the digital watermark in the print image data.

<Configuration of printing device and host device>
Hereinafter, the configuration of the printing apparatus and its upper level apparatus will be described. FIG. 1 is a diagram illustrating a configuration of a printing apparatus and a host apparatus according to the first embodiment.

  As shown in FIG. 1, the printing apparatus 1 is connected to the upper apparatus 11 and the memory medium 21 and acquires print data from the upper apparatus 11 and the memory medium 21. Such a printing apparatus 1 includes an input / output unit 100, a processing unit 200, a data storage unit 300, a printing unit 400, a reading unit 500, a transport mechanism (not shown) that transports the print medium 31, and other components. .

  The input / output unit 100 of the printing apparatus 1 is a component that inputs and outputs various data online with an external device. The input / output unit 100 includes, for example, an I / O interface (input / output interface) 111 for inputting / outputting various data online to / from the host device 11, a slot 113 for inputting / outputting various data to / from the memory medium 21, A switch 121 operated by the printer, a display 131 for displaying data to be viewed by the printer, and the like are provided. The I / O interface 111 and the slot 113 constitute a data acquisition unit 110 that acquires print data from the outside.

  The processing unit 200 of the printing apparatus 1 is configured by a CPU and is a component that processes various calculations. The processing unit 200 includes, for example, a control unit 200 ′, a print image forming unit 201, an embedded data generating unit 203, a tint block image forming unit 205, an image composition unit 207, a watermark data extracting unit 211, an extraction result determining unit 213, and the like. Functional means are provided.

  The control unit 200 ′ of the printing apparatus 1 is a functional unit that controls each unit of the printing apparatus 1 and performs various calculations.

  The print image forming unit 201 of the printing apparatus 1 is a functional unit that forms image data of a print image (hereinafter referred to as print image data) based on the print data acquired by the data acquisition unit 110. In the example illustrated in FIG. 1, the print image forming unit 201 forms print image data based on the print data acquired from the host device 11, but based on the print data acquired from the memory medium 21, Print image data can also be formed. Note that the print data is usually binary or multivalued bit data when acquired from the host apparatus 11. At this time, the print data usually includes a page description language such as a page script. The print data is usually image data when acquired from the memory medium 21.

  The embedded data generation unit 203 of the printing apparatus 1 also embeds data (hereinafter referred to as a digital watermark) in a print image based on the print data acquired by the data acquisition unit 110 and the apparatus data stored in the data storage unit 300. Is referred to as embedded data). The device data and the embedded data are binary or multivalued bit data. The embedded data generation unit 203 can embed candidate data with high priority from a group of candidate data groups that are candidates for embedded data when the amount of embedded data exceeds the upper limit of the amount of data that can be embedded. Extraction is performed until the amount of data is reached, and embedded data is generated based on the extracted candidate data. In the example illustrated in FIG. 1, the embedded data generation unit 203 generates embedded data based on the print data acquired from the host device 11, but the embedded data generation unit 203 embeds the embedded data based on the print data acquired from the memory medium 21. Data can also be generated. In this embodiment, the embedded data generation unit 203 once generates tracking data (that is, data that can track the occurrence of the printing action) based on the print data and the device data, and the tracking is performed. Embedded data is generated by encoding the data.

  The copy-forgery-inhibited pattern image forming unit 205 of the printing apparatus 1 is a functional unit that forms image data of a digital watermark copy-forgery-inhibited pattern image (hereinafter referred to as copy-forgery-inhibited pattern image data) based on the embedded data generated by the embedded data generating unit 203. is there.

  In addition, the image composition unit 207 of the printing apparatus 1 synthesizes the print image data formed by the print image forming unit 201 and the copy-forgery-inhibited pattern image data formed by the copy-forgery-inhibited pattern image forming unit 205 to generate image data of a watermarked print image. Is a functional means for forming the composite image data.

  The watermark data extraction unit 211 of the printing apparatus 1 is a functional unit that extracts copy-forgery-inhibited pattern image data embedded in a print image as a digital watermark from read data described later. Hereinafter, the tint block image data extracted by the watermark data extraction unit 211 is referred to as watermark data in order to distinguish it from the tint block image data formed by the tint block image forming unit 205. In this embodiment, the watermark data extraction unit 211 has a function of further extracting embedded data from the watermark data.

  In addition, the extraction result determination unit 213 of the printing apparatus 1 compares the embedded data generated by the embedded data generation unit 203 with the embedded data extracted from the watermark data by the watermark data extraction unit 211, and uses the watermarked print image. This is function means for determining whether a composite image is correctly printed on the print medium 31. The extraction result determination unit 213 determines that the composite image, which is a watermarked print image, is correctly printed on the print medium 31 when both match within a predetermined allowable range, and both are within the predetermined allowable range. If they do not match, it is determined that the composite image is not correctly printed on the print medium 31.

  The data storage unit 300 of the printing apparatus 1 is configured by a RAM and is a component that stores various data including apparatus data. In the example shown in FIG. 1, the device data is stored in the data storage unit 300 of the printing device 1, but the device data may be stored in the data storage unit 80 of the upper level device 11.

  The printing unit 400 of the printing apparatus 1 is a component that prints an image such as a document or a graphic (including a photograph, a picture, a table, or the like) on a print medium 31 such as paper. The printing unit 400 prints a composite image, which is a watermarked print image, on the print medium 31 based on the composite image data formed by the image composition unit 207. The printing unit 400 configures a watermark embedding unit 600 that embeds a digital watermark in a print image together with the print image forming unit 201, the embedded data generation unit 203, the tint block image forming unit 205, and the image composition unit 207 of the processing unit 200. ing.

  The reading unit 500 of the printing apparatus 1 optically reads the print medium 31 and distinguishes it from composite image data (hereinafter referred to as composite image data formed by the image composition unit 207) that is image data of a watermarked print image from the print medium 31. (Referred to as read data). The reading unit 500, together with the watermark data extraction unit 211 and the extraction result determination unit 213 of the processing unit 200, constitutes a watermark detection unit 700 that detects a digital watermark from a print image. The watermark detection unit 700 is provided to verify whether or not a composite image that is a watermarked print image is correctly printed on the print medium 31.

  On the other hand, as shown in FIG. 1, the host device 11 includes a processing unit 50, a data storage unit 80, an I / O interface 91, and other components. The host device 11 is connected to a display 13, an input unit 15 such as a keyboard (KB) and a mouse, and other devices.

  The processing unit 50 of the host device 11 is configured by a CPU and is a component that processes various calculations. The processing unit 50 includes, for example, a control unit 50 ′, a print image forming unit 61, a tracking data generation unit 71, and other functional units.

  The control unit 50 ′ of the host device 11 is a functional unit that controls each unit of the host device 11 and performs various calculations.

  The print image forming unit 61 of the host device 11 is a functional unit that forms print image data based on the print data stored in the data storage unit 80.

  The tracking data generation unit 71 of the host device 11 is a functional unit that extracts embedded data 1025a described later from watermark data 1023 described later, decodes the embedded data 1025a, and acquires (generates) tracking data 1025b described later. is there.

  The data storage unit 80 of the host device 11 is configured by a RAM and is a component that stores various data and programs including print data.

  The I / O interface 91 of the host device 11 is a component that inputs and outputs various data online with the printing apparatus 1 and other external devices.

  The memory medium 21 is a medium for storing various image data such as a memory card, a DVD, a CD-ROM, and a portable HDD device. The memory medium 21 stores image data of various images (for example, photographs taken by a digital camera). The memory medium 21 may be in the form of a portable memory device (for example, a memory chip built-in device or a hard disk drive device).

<Operation of printing device and host device>
Hereinafter, operations of the printing apparatus 1 and the host apparatus 11 will be described. In this embodiment, it is assumed that the printer has operated the input unit 15 of the host apparatus 11 to give a print instruction to print an image such as a desired document or graphic.

  FIG. 2 is a diagram illustrating an operation flow of the printing apparatus and the host apparatus according to the first embodiment. FIG. 3 is an operation explanatory diagram of the printing apparatus and the host apparatus according to the first embodiment, and illustrates an example of an image formed in each process illustrated in FIG. 2 or an example of an image to be used.

  A printer operates the input unit 15 of the host device 11 to give an instruction to print an image such as a document or a graphic. As a result, as shown in FIG. 2, the processing unit 50 (specifically, the control unit 50 ') of the upper level apparatus 11 acquires the print instruction (S501). Then, the processing unit 50 (specifically, the control unit 50 ′) of the upper level apparatus 11 prints the print data 1001 such as a document or a graphic to be printed on the print medium 31 (see FIG. 1) based on the print instruction acquired in S501. 3 is specified (S503), and the specified print data 1001 is read from the data storage unit 80 and output to the printing apparatus 1 via the I / O interface 91 (S505).

  The processing unit 200 (specifically, the control unit 200 ′) of the printing apparatus 1 acquires the print data 1001 from the upper level apparatus 11 via the I / O interface 111 of the data acquisition unit 110 (S 1001). The print data 1001 acquired at this time is input to the print image forming unit 201 and the embedded data generation unit 203 (see FIG. 1). In this embodiment, the printing apparatus 1 acquires the print data 1001 from the upper level apparatus 11, but may acquire the print data 1001 from the memory medium 21.

  Next, the print image forming unit 201 of the printing apparatus 1 forms print image data 1003 (see FIGS. 1 and 3) based on the print data 1001 (S1003).

  At this time, the print image forming unit 201 first acquires the print data 1001 from the host device 11 and recognizes the extension attached to the file name of the acquired print data 1001. In this embodiment, it is assumed that the extension added to the file name of the print data 1001 is a code meaning a document file. In this case, the print image forming unit 201 recognizes the print data 1001 as a document file from the extension of the print data 1001. The print image forming unit 201 forms print image data 1003 that is image data of a document image from the print data 1001 based on the recognized file format.

  Alternatively, at this time, the print image forming unit 201 first acquires the print data 1001 to which the designated address data (not shown) is attached from the host device 11 and recognizes the designated address data. This designated address designates a specific address of the data storage unit 300. The data storage unit 300 stores the file format of the document data at the address specified by the specified address. The print image forming unit 201 acquires a file format (not shown) of document data from the data storage unit 300 through a route (not shown) based on the recognized designated address. In this embodiment, the file format means one format of the document file. The print image forming unit 201 forms print image data 1003 that is image data of a document image from the print data 1001 based on the acquired file format.

  Thereafter, the print image forming unit 201 outputs the print image data 1003 to the image composition unit 207.

  Next, the embedded data generation unit 203 of the printing apparatus 1 generates embedded data 1005b (see FIGS. 1 and 3) based on the print data 1001 and the apparatus data 1004 (S1005). At this time, the embedded data generation unit 203 first acquires the print data 1001 from the data acquisition unit 110 and the apparatus data 1004 from the data storage unit 300. Next, the embedded data generation unit 203 extracts, for example, one or more types of data used for the digital watermark from the print data 1001 and the device data 1004, or sets the data used for the digital watermark in a predetermined priority order. The tracking data 1005a (see FIG. 3) is generated by arranging according to the above, and the tracking data 1005a is encoded to generate the embedded data 1005b. Thereafter, the embedded data generating unit 203 outputs the embedded data 1005b to the copy-forgery-inhibited pattern image forming unit 205 and the extraction result determining unit 213.

  Next, the copy-forgery-inhibited pattern image forming unit 205 of the printing apparatus 1 forms copy-forgery-inhibited pattern image data 1007 (see FIGS. 1 and 3) based on the embedded data 1005b (S1007). At this time, the copy-forgery-inhibited pattern image forming unit 205 first acquires the embedded data 1005 b from the embedded data generating unit 203 and also acquires size data such as the width and height of the print image data 1003 from the print image forming unit 201. The copy-forgery-inhibited pattern image forming unit 205 forms copy-forgery-inhibited pattern image data 1007 based on the embedded data 1005b so as to have the same size as the size of the print image data 1003. The copy-forgery-inhibited pattern image data 1007 is defined based on the embedded data 1005b as, for example, invisible embedded pixel data 1008a defined as an array pattern that represents a 0-bit value and an array pattern that represents a 1-bit value. The invisible embedded pixel data 1008b is configured according to a predetermined rule for generating a digital watermark (see FIG. 3). Thereafter, the tint block image forming unit 205 outputs the tint block image data 1007 to the image composition unit 207.

  Next, the image composition unit 207 of the printing apparatus 1 synthesizes the print image data 1003 acquired from the print image forming unit 201 and the copy-forgery-inhibited pattern image data 1007 acquired from the copy-forgery-inhibited pattern image formation unit 205 to generate composite image data 1009 (FIG. 1). (See FIG. 3) (S1009). At this time, the image composition unit 207 first acquires the print image data 1003 from the print image forming unit 201 and also acquires the copy-forgery-inhibited pattern image data 1007 from the copy-forgery-inhibited pattern image forming unit 205. Then, the image composition unit 207 performs threshold processing on the print image data 1003 and the copy-forgery-inhibited pattern image data 1007 as a binary image in which the luminance value of the white pixel is 1 and the luminance value of the black pixel is 0, and the print image data 1003 AND condition of the copy-forgery-inhibited pattern image data 1007 is calculated. As a result, the image composition unit 207 composes the print image data 1003 and the copy-forgery-inhibited pattern image data 1007 to form composite image data 1009. Thereafter, the image composition unit 207 outputs the composite image data 1009 to the printing unit 400.

  Next, the printing unit 400 of the printing apparatus 1 acquires the composite image data 1009 from the image composition unit 207, and based on the composite image data 1009, a print image 1011 that is a watermarked print image (see FIGS. 1 and 3). Is printed on the print medium 31 (S1011).

  Next, the reading unit 500 of the printing apparatus 1 reads the print image 1011 from the print medium 31 and acquires the read data 1021 (see FIGS. 1 and 3) (S1021). The read data 1021 is data that substantially matches the composite image data 1009 if the print image 1011 is correctly printed on the print medium 31, although it slightly changes depending on the reading capability of the reading unit 500 and the situation at the time of reading. Thereafter, the reading unit 500 outputs the read data 1021 to the watermark data extraction unit 211. Note that S1021 is the next step after S1011. However, S1021 may be immediately after S1011 (that is, “print processing”), or may be after a while has elapsed since S1011.

  Next, the watermark data extraction unit 211 of the printing apparatus 1 extracts watermark data 1023 (see FIGS. 1 and 3), which is digital watermark copy-forgery-inhibited pattern image data embedded in the print image 1011 from the read data 1021 (S1023). . At this time, the watermark data extraction unit 211 acquires the read data 1021 from the reading unit 500, and embedded pixel data 1008a meaning a 0-bit value or embedded pixel data meaning a 1-bit value with respect to the read data 1021. Based on 1008b, pattern matching is performed, or filter processing corresponding to embedded pixel data 1008a and 1008b is performed. As a result, the watermark data extraction unit 211 extracts the watermark data 1023 from the read data 1021. Although the watermark data 1023 slightly changes depending on the reading capability of the reading unit 500 and the situation at the time of reading, if the print image 1011 is correctly printed on the print medium 31, the watermark data 1023 is data that substantially matches the copy-forgery-inhibited pattern image data 1007. is there.

  Next, the watermark data extraction unit 211 of the printing apparatus 1 extracts embedded data 1025a (see FIGS. 1 and 3) from the watermark data 1023 (S1025). The embedded data 1025a is data embedded in the print image 1011 as a digital watermark. The embedded data 1025a is data that matches the embedded data 1005b generated in step S1005 if the print image 1011 is correctly printed on the print medium 31. Thereafter, the watermark data extraction unit 211 outputs the watermark data 1023 and the embedded data 1025a to the extraction result determination unit 213.

  Next, the extraction result determination unit 213 of the printing apparatus 1 compares the embedded data 1005b and the embedded data 1025a as shown by the bidirectional arrows in FIG. 3, and the print image 1011 is correctly printed on the print medium 31. It is determined whether or not (S1027). At this time, the extraction result determination unit 213 first acquires the embedded data 1005 b from the embedded data generation unit 203 and also acquires the watermark data 1023 from the watermark data extraction unit 211. Then, the extraction result determination unit 213 compares the embedded data 1005b with the embedded data 1025a. At this time, when the two match within a predetermined allowable range, the extraction result determination unit 213 determines that “the print image 1011 is correctly printed on the print medium 31 (or the print image 1011 has been cheated. No) ”. In this case, the process proceeds to S1031. On the other hand, when the two do not match within the predetermined allowable range, the extraction result determination unit 213 indicates that “the print image 1011 has not been correctly printed on the print medium 31 (or the print image 1011 has been cheated. ) ”. In this case, the process proceeds to S1051.

  If it is determined in S1027 that “the print image 1011 is correctly printed on the print medium 31”, the extraction result determination unit 213 uses the watermark data 1023 extracted by the watermark data extraction unit 211 as the I / O interface 111. To the higher-level device 11 (S1031).

  The processing unit 50 of the upper level apparatus 11 acquires the watermark data 1023 from the printing apparatus 1 via the I / O interface 91 (S1033). The watermark data 1023 acquired at this time is input to the data storage unit 80 and the tracking data generation unit 71 (see FIG. 1).

  Next, the processing unit 50 (specifically, the control unit 50 ′) of the upper level apparatus 11 stores the watermark data 1023 acquired from the printing apparatus 1 in the data storage unit 80 (S 1035). Thereby, the watermark data 1023 is stored in the data storage unit 80 of the higher-level device 11.

  Next, the tracking data generation unit 71 of the host device 11 extracts the embedded data 1025a from the watermark data 1023, decodes the embedded data 1025a, and generates the tracking data 1025b (see FIG. 3) (S1037).

  Next, the print image forming unit 61 of the host apparatus 11 reads the print data 1001 output to the printing apparatus 1 in S1001 from the data storage unit 80, and print image data 1027 based on the read print data 1001 (see FIG. 3). Is formed (S1039). Hereinafter, the print image data 1027 read from the data storage unit 80 is referred to as original print image data 1027. Note that the original print image data 1027 is usually data that matches the print image data 1003 formed in S1003.

  Next, the processing unit 50 (specifically, the control unit 50 ′) of the host apparatus 11 displays the tracking data 1025b, the original print image data 1027, and others on the display 13 (S1041), and these are displayed to the printer. Let me check. The printer (or the administrator of the printer) browses the screen displayed on the display 13 and checks the data displayed on the screen to detect fraudulent acts such as copying or falsification of the print image 1011. be able to.

  When it is determined in S1027 that “the print image 1011 is not printed correctly on the print medium 31”, the extraction result determination unit 213 determines that “the print image 1011 is not printed correctly on the print medium 31 (or Error data (see FIG. 1) indicating that the print image 1011 has been cheated) and watermark data 1023 are output to the upper level apparatus 11 via the I / O interface 111 (S1051). At this time, if S1021 is immediately after S1011 (that is, “reading process” is immediately after “printing process”) and the printing unit 400 is in the printing process, the extraction result determination unit 213 displays the printing unit. 400 causes the printing process to be stopped.

  The processing unit 50 of the host apparatus 11 acquires error data and watermark data 1023 from the printing apparatus 1 via the I / O interface 91 (S1053). The error data and watermark data 1023 acquired at this time are input to the data storage unit 80 and the tracking data generation unit 71 (see FIG. 1).

  Next, the processing unit 50 (specifically, the control unit 50 ′) of the upper level apparatus 11 stores the error data and watermark data 1023 acquired from the printing apparatus 1 in the data storage unit 80 (S 1055). As a result, the error data and watermark data 1023 are stored in the data storage unit 80 of the higher-level device 11.

  Next, similarly to S1037, the tracking data generation unit 71 of the host device 11 extracts the embedded data 1025a from the watermark data 1023, decodes the embedded data 1025a, and generates the tracking data 1025b (S1057).

  Next, similarly to S1039, the print image forming unit 61 of the upper level apparatus 11 reads the print data 1001 output to the printing apparatus 1 in S1001 from the data storage unit 80, and the original print image data based on the read print data 1001. 1027 is formed (S1059).

  Next, the processing unit 50 (specifically, the control unit 50 ′) of the host apparatus 11 displays error display and tracking data 1025b, original print image data 1027, and others on the display 13 (S1061). Ask the printer to confirm. The printer (or the administrator of the printer) browses the screen displayed on the display 13 and checks the data displayed on the screen to detect fraudulent acts such as copying or falsification of the print image 1011. be able to. In particular, when tampering is detected, the printer (or the manager of the printer) can display the tampered part on the display 13 and check the tampered content in detail. The printer who has confirmed the display of the error causes the printing apparatus 1 to print again, prints to another printing apparatus (not shown), or takes other measures depending on the situation. At this time, the printer stores or discards the print medium 31 on which the print image 1011 is printed, depending on the situation.

  As described above, a series of operations of the printing apparatus 1 and the host apparatus 11 are completed.

  The error display may be displayed on the display 131 of the printing apparatus 1.

  Further, the watermark data 1023 may be decoded by the extraction result determination unit 213 of the printing apparatus 1. Then, the tracking data 1025b acquired thereby may be displayed on the display 131 of the printing apparatus 1.

  As described above, according to this embodiment, the printing apparatus 1 that is a terminal apparatus automatically performs digital watermarking (background pattern image data) on all print images 1011 based on the print data 1001 and the apparatus data 1004. 1007) is generated and embedded. Accordingly, the printing apparatus 1 can always embed a digital watermark in all print images even when the host apparatus 11 does not generate a digital watermark or embed a digital watermark in a print image.

  Therefore, the printing apparatus 1 according to this embodiment can prevent printing of a print image in which a digital watermark is not embedded, and can always cause the printer or its administrator to track the occurrence of a printing action. . As a result, the printing apparatus 1 according to this embodiment can improve the security of the print image printed on the print medium as compared with the conventional technique.

  In addition, the printer does not need to manually operate the embedding software, and the setting for embedding the tracking data in the print image manually for each print medium and the printing apparatus for appropriately printing the digital watermark There is no need to make any settings. As a result, the printing apparatus 1 according to the first embodiment can reduce the burden on the printer.

  The second embodiment is characterized in that reduced print image data 1006 is used as a digital watermark for detecting falsification of the print image 1011. The reduced print image data 1006 is data formed by reducing the print image data 1003 so as to be less than or equal to the amount of data that can be embedded as a digital watermark. For the reduction of the print image data 1003, for example, a method such as MMR (Modified Modified Read Code), JBIG (Joint Bi-level Image experts Group), MR (Modified Read Code), or the like is used. Since these are well-known, detailed description is abbreviate | omitted here.

<Configuration of printing device and host device>
Hereinafter, the configuration of the printing apparatus and its upper level apparatus will be described. FIG. 4 is a diagram illustrating the configuration of the printing apparatus and the host apparatus according to the second embodiment.

  As illustrated in FIG. 4, the printing apparatus 1 according to this embodiment includes the same components and functional units as the printing apparatus 1 according to the first embodiment. However, in the printing apparatus 1 according to this embodiment, (1) the print image forming unit 201 has a function of forming reduced print image data 1006 (described later) based on the print image data 1003. (2) A function for forming a copy-forgery-inhibited pattern image data 1007 based on the embedded data 1005b and the reduced print image data 1006 is added to the copy-forgery-inhibited pattern image forming unit 205, and (3) watermark data 1023 is added to the watermark data extracting unit 211. Thus, it is different from the printing apparatus 1 according to the first embodiment in that a function of extracting reduced print image data 1024 in addition to the embedded data 1025a is added. Note that the reduced print image data 1024 is data that substantially matches the reduced print image data 1006 formed by reducing the print image data 1003, although it varies somewhat depending on the reading capability of the reading unit 500 and the situation at the time of reading. .

  On the other hand, as shown in FIG. 4, the host device 11 according to this embodiment includes a verification unit 73 in addition to the components and functional means of the host device 11 according to the first embodiment.

  The verification unit 73 is a functional unit that verifies whether a fraudulent act has been performed on the print image 1011 by comparing the brightness value of restored print image data 1026 described later and the brightness value of the original print image data 1027. .

  In this embodiment, the print image forming unit 61 of the host apparatus 11 expands the reduced print image data 1024 to the size before reduction, and forms the restored print image data 1026 described later, and the print data 1001. And a function of forming original print image data 1027 based on this.

<Operation of printing device and host device>
Hereinafter, operations of the printing apparatus 1 and the host apparatus 11 will be described. In this embodiment, it is assumed that the printer has operated the input unit 15 of the host apparatus 11 to give a print instruction to print an image such as a desired document or graphic.

  FIG. 5 is a diagram illustrating an operation flow of the printing apparatus and the host apparatus according to the second embodiment. FIG. 6 is an operation explanatory diagram of the printing apparatus and the host apparatus according to the second embodiment, and illustrates an example of an image formed in each process illustrated in FIG. 5 or an example of an image to be used.

  A printer operates the input unit 15 of the host device 11 to give an instruction to print an image such as a document or a graphic. Thereby, as shown in FIG. 5, the host device 11 operates in the same manner as in the first embodiment in S501 to S505. That is, the processing unit 50 (specifically, the control unit 50 ′) of the upper level apparatus 11 acquires a print instruction (S501), and prints a document or a graphic to be printed on the print medium 31 based on the print instruction. The data 1001 is specified (S503), the specified print data 1001 is read from the data storage unit 80, and is output to the printing apparatus 1 via the I / O interface 91 (S505).

  The printing apparatus 1 also operates in the same manner as in the first embodiment in S1001 to S1005. That is, first, the processing unit 200 (specifically, the control unit 200 ') of the printing apparatus 1 acquires the print data 1001 from the upper level apparatus 11 (S1001). Next, the print image forming unit 201 of the printing apparatus 1 forms print image data 1003 based on the print data 1001 (S1003). The embedded data generation unit 203 of the printing apparatus 1 generates tracking data 1005a (see FIG. 6) based on the print data 1001 and the apparatus data 1004, and further encodes the tracking data 1005a to embed data 1005b. Is generated (S1005). Thereafter, the embedded data generating unit 203 outputs the embedded data 1005b to the copy-forgery-inhibited pattern image forming unit 205 and the extraction result determining unit 213.

  Next, the print image forming unit 201 of the printing apparatus 1 reduces the print image data 1003 formed in S1003 so as to be less than or equal to the amount of data that can be embedded as a digital watermark, and reduces the print image data 1006 (FIG. 4). (See FIG. 6) is formed (S1006). Thereafter, the print image forming unit 201 outputs the reduced print image data 1006 to the copy-forgery-inhibited pattern image forming unit 205.

  Next, the tint block image forming unit 205 of the printing apparatus 1 forms tint block image data 1007 (S1007). However, in this embodiment, unlike the first embodiment, the copy-forgery-inhibited pattern image forming unit 205 forms copy-forgery-inhibited pattern image data 1007 based on the embedded data 1005b and the reduced print image data 1006. Specifically, the copy-forgery-inhibited pattern image forming unit 205 first acquires the embedded data 1005b from the embedded data generating unit 203, and the width and height of the reduced print image data 1006 and the print image data 1003 from the print image forming unit 201. Get size data for. Next, the copy-forgery-inhibited pattern image forming unit 205 forms copy-forgery-inhibited pattern image data 1007 based on the embedded data 1005b so as to have a size similar to the size of the print image data 1003. The copy-forgery-inhibited pattern image data 1007 is defined based on the embedded data 1005b as, for example, invisible embedded pixel data 1008a defined as an array pattern that represents a 0-bit value and an array pattern that represents a 1-bit value. The invisible embedded pixel data 1008b is arranged in accordance with a predetermined rule for generating a digital watermark, thereby generating image data to be a base of the digital watermark copy-forgery-inhibited pattern image data 1007, and the image data is Applying to the reduced print image data 1006, digital watermark copy-forgery-inhibited pattern image data 1007 is formed. Thereafter, the tint block image forming unit 205 outputs the tint block image data 1007 to the image composition unit 207.

  Next, the printing apparatus 1 operates in the same manner as in the first embodiment in S1009 to S1021. That is, first, the image composition unit 207 of the printing apparatus 1 composes the print image data 1003 and the copy-forgery-inhibited pattern image data 1007 to form composite image data 1009 (S1009). Next, the printing unit 400 of the printing apparatus 1 prints the print image 1011 on the print medium 31 based on the composite image data 1009 (S1011). Next, the reading unit 500 of the printing apparatus 1 reads the print image 1011 from the print medium 31 and acquires the read data 1021 (S1021).

  After S1021, the watermark data extraction unit 211 of the printing apparatus 1 extracts watermark data 1023, which is digital watermark copy-forgery-inhibited pattern image data embedded in the print image 1011 from the read data 1021, as in the first embodiment (S1023). . In this embodiment, the watermark data 1023 is configured based on reduced print image data 1024 (see FIG. 6) and embedded data 1025a. As described above, the reduced print image data 1024 is data that matches the reduced print image data 1006 generated in S1006 if the print image 1011 is correctly printed on the print medium 31. The embedded data 1025a is data that matches the embedded data 1005b generated in S1005 if the print image 1011 is correctly printed on the print medium 31. The reduced print image data 1024 is restored to the size before reduction, and the brightness value of the restored image data is compared with the brightness value of the print image data 1003, so that illegal actions such as duplication or falsification of the print image 1011 are performed. It can be used to determine the presence or absence of. The embedded data 1005b can be used to determine whether the print image 1011 is correctly printed on the print medium 31 by comparing with the tracking data 1025b.

  Next, the printing apparatus 1 operates in the same manner as in the first embodiment in S1025 to S1027. That is, first, the watermark data extraction unit 211 of the printing apparatus 1 extracts embedded data 1025a from the watermark data 1023 (S1025). Next, the extraction result determination unit 213 of the printing apparatus 1 compares the embedded data 1005b with the embedded data 1025a to determine whether the print image 1011 is correctly printed on the print medium 31 (S1027). When the embedded data 1005b and the embedded data 1025a match within a predetermined allowable range, the extraction result determination unit 213 determines that “the print image 1011 has been correctly printed on the print medium 31 (and the print image 1011 has been fraudulent. Not applied) ”. In this case, the process proceeds to S1032. On the other hand, when the embedded data 1005b and the embedded data 1025a do not match within a predetermined allowable range, the extraction result determination unit 213 determines that “the print image 1011 is not printed correctly on the print medium 31 (or the print image 1011 is illegal). It is determined that the action is being performed. In this case, the process proceeds to S1051.

  If it is determined in S1027 that “the print image 1011 is correctly printed on the print medium 31”, the extraction result determination unit 213 uses the watermark data 1023 extracted by the watermark data extraction unit 211 as the I / O interface 111. To the higher-level device 11 (S1032). Note that this watermark data 1023 includes reduced print image data 1024, unlike the watermark data 1023 of the first embodiment.

  The host device 11 operates in the same manner as in the first embodiment in S1033 to S1037. That is, first, the processing unit 50 (specifically, the control unit 50 ′) of the upper level apparatus 11 acquires the watermark data 1023 from the printing apparatus 1 via the I / O interface 91 (S 1033). The watermark data 1023 acquired at this time is input to the data storage unit 80, the tracking data generation unit 71, and the print image forming unit 61 (see FIG. 4). Next, the processing unit 50 (specifically, the control unit 50 ′) of the upper level apparatus 11 stores the watermark data 1023 acquired from the printing apparatus 1 in the data storage unit 80 (S 1035). Then, the tracking data generation unit 71 of the host device 11 extracts the embedded data 1025a from the watermark data 1023, decodes the embedded data 1025a, and generates the tracking data 1025b (S1037).

  Next, the print image forming unit 61 of the host apparatus 11 extracts the reduced print image data 1024 from the watermark data 1023, expands the reduced print image data 1024 to the size before reduction, and restores the print image data 1026 (FIG. 6). Reference) is formed (S1038). Note that the restored print image data 1026 is the same data as the print image data 1003 formed in S1003 if the print image 1011 is not cheated.

  Next, as in the first embodiment, the print image forming unit 61 of the host apparatus 11 forms original print image data 1027 based on the print data 1001 output to the printing apparatus 1 in S1001 (S1039). Thereafter, the print image forming unit 61 outputs the restored print image data 1026 formed in S1038 and the original print image data 1027 formed in S1039 to the verification unit 73.

  Next, the verification unit 73 of the host apparatus 11 compares the brightness value of the restored print image data 1026 and the brightness value of the original print image data 1027 and determines whether or not they match within a predetermined allowable range. (S1043). That is, the verification unit 73 determines whether the difference between the luminance value of the restored print image data 1026 and the luminance value of the original print image data 1027 is smaller than a predetermined threshold value. As a result, the host apparatus 11 can automatically detect fraudulent acts such as copying and falsification of the print image 1011. When the brightness value of the restored print image data 1026 matches the brightness value of the original print image data 1027 within a predetermined allowable range (that is, the difference between the brightness value of the restored print image data 1026 and the brightness value of the original print image data 1027) Is smaller than a predetermined threshold value), the verification unit 73 of the host device 11 determines that “there is no fraudulent action on the print image 1011”. In this case, the process proceeds to S1045. On the other hand, when the restored print image data 1026 and the original print image data 1027 do not match within a predetermined allowable range (that is, the difference between the brightness value of the restored print image data 1026 and the brightness value of the original print image data 1027 is determined in advance. If the threshold value is larger than the threshold value, the verification unit 73 of the higher-level device 11 determines that “there was an illegal act on the print image 1011”. In this case, the process proceeds to S1047.

  When it is determined in S1043 that “the restored print image data 1026 and the original print image data 1027 match within a predetermined allowable range”, the verification unit 73 (or the control unit 50 ′) performs the tracking data 1025b and the restored print image. The image data 1026, the original print image data 1027, a display indicating that there is no fraud, and the like are displayed on the display 13 (S1045), and the printer is confirmed.

  On the other hand, when it is determined in S1043 that “the restored print image data 1026 and the original print image data 1027 do not match within a predetermined allowable range”, the verification unit 73 (or the control unit 50 ′) performs the tracking data 1025b or The restored print image data 1026, the original print image data 1027, an indication that there is an illegal act such as falsification, and the like are displayed on the display 13 (S1047), and the printer is confirmed.

  If it is determined in S1027 that “the print image 1011 is not correctly printed on the print medium 31”, the extraction result determination unit 213 sends the error data and watermark data 1023 via the I / O interface 111. The data is output to the host device 11 (S1051). Note that FIG. 4 shows an example in which it is determined in S1027 that “the print image 1011 is correctly printed on the print medium 31”, and therefore error data is omitted. In this embodiment, the watermark data 1023 includes reduced print image data 1024. At this time, if S1021 is immediately after S1011 (that is, “reading process” is immediately after “printing process”) and the printing unit 400 is in the printing process, the extraction result determination unit 213 displays the printing unit. 400 causes the printing process to be stopped.

  The host device 11 operates in the same manner as in the first embodiment in S1053 to S1057. That is, first, the processing unit 50 of the upper level apparatus 11 acquires error data and watermark data 1023 from the printing apparatus 1 via the I / O interface 91 (S1053). The error data and watermark data 1023 acquired at this time are input to the data storage unit 80, the tracking data generation unit 71, and the print image forming unit 61 (see FIG. 4). Next, the processing unit 50 (specifically, the control unit 50 ′) of the upper level apparatus 11 stores the watermark data 1023 acquired from the printing apparatus 1 in the data storage unit 80 (S 1055). Then, the tracking data generation unit 71 of the host device 11 extracts the embedded data 1025a from the watermark data 1023, decodes the embedded data 1025a, and generates the tracking data 1025b (S1057).

  Next, the processing unit 50 of the upper level apparatus 11 extracts the reduced print image data 1024 from the watermark data 1023, enlarges the reduced print image data 1024 to the size before reduction, and forms restored print image data 1026 (S1058). ).

  Next, as in the first embodiment, the print image forming unit 61 of the host apparatus 11 forms original print image data 1027 based on the print data 1001 output to the printing apparatus 1 in S1001 (S1059). Thereafter, the print image forming unit 61 outputs the restored print image data 1026 and the original print image data 1027 formed in S1038 to the verification unit 73 (or the control unit 50 ').

  Next, the verification unit 73 (or the control unit 50 ′) of the host device 11 displays error display and tracking data 1025b, restored print image data 1026, original print image data 1027, and others on the display 13 (S1061). ) Ask the printer to confirm these. The printer who has confirmed the display of the error causes the printing apparatus 1 to print again, prints to another printing apparatus (not shown), or takes other measures depending on the situation. At this time, the printer stores or discards the print medium 31 on which the print image 1011 is printed, depending on the situation.

  As described above, a series of operations of the printing apparatus 1 and the host apparatus 11 are completed.

  Note that the printing apparatus 1 and the host apparatus 11 according to this embodiment can also operate in the same manner as in the first embodiment.

  In general, there is an upper limit to the amount of data that can be embedded as digital watermark data. For this reason, the data amounts of the tracking data 1005a and the reduced print image data 1006 to be embedded as a digital watermark need not exceed the upper limit that can be embedded. Therefore, for example, a priority is set between the tracking data 1005a and the reduced print image data 1006, and when the data amount of the tracking data 1005a and the reduced print image data 1006 exceeds the embeddable upper limit, the reduced print for falsification detection is performed. The image data 1006 may be embedded with priority.

  As described above, according to this embodiment, the printing apparatus 1 outputs the reduced print image data 1024 that is a digital watermark for detecting falsification of the print image 1011 to the upper level apparatus 11.

  Therefore, the printing apparatus 1 according to this embodiment has the same effect as that of the first embodiment (that is, the effect that “the security of a print image printed on a print medium can be improved as compared with the conventional technology”, and In addition to the effect that “the burden on the printer can be reduced”), the host device 11 can also detect illegal acts such as copying and falsification of the print image 1011.

  The third embodiment is characterized in that the host apparatus 11 generates a digital watermark, and the printing apparatus 1 has a configuration corresponding thereto. Therefore, in this embodiment, the host device 11 acquires device data from the printing device 1 and generates a digital watermark using the device data. According to this embodiment, the printer can cause the printing apparatus 1 to print the watermarked print image 1011 on the print medium 31 from the remote host apparatus 11. Hereinafter, in order to distinguish a higher-level device that generates a digital watermark from a higher-level device that does not generate a digital watermark, it is referred to as a higher-level device 11 ′.

  In this embodiment, the upper level apparatus 11 ′ does not directly output the composite image data 1009, which is the image data of the watermarked print image, to the printing apparatus 1, but print data 1001 before image formation and a background pattern code described later. The compressed data 1007 ′ is reversibly compressed as one data to generate compressed data 1031 described later, and the compressed data 1031 is output to the printing apparatus 1. As a result, in this embodiment, the host apparatus 11 ′ uses less data for printing the watermarked print image 1011 (in this embodiment, compressed data 1031 including the print data 1001 and the tint block encoded data 1007 ′). The amount of data can be output to the printing apparatus 1 connected via the network 41.

<Configuration of printing device and host device>
Hereinafter, the configuration of the printing apparatus and its upper level apparatus will be described. FIG. 7 is a diagram illustrating the configuration of the printing apparatus and the host apparatus according to the third embodiment. Here, a description will be given based on the second embodiment. Therefore, in the following, components that are different from the printing device 1 and the host device 11 according to the second embodiment will be described mainly, and components that are common to the printing device 1 and the host device 11 according to the second embodiment and similar components will be described. Will not be described. In FIG. 7, the printing apparatus 1 is connected to the upper apparatus 11 ′ that generates the digital watermark via the network 41, but can also be connected to the upper apparatus 11 that does not generate the digital watermark.

  As illustrated in FIG. 7, the printing apparatus 1 according to this embodiment includes a compressed data decompression unit 200 a in addition to the components and functional units of the printing apparatus 1 according to the second embodiment.

  The compressed data decompressing unit 200a is a functional unit that decompresses compressed data 1031 to be described later and obtains print data 1001 and ground pattern encoded data 1007 'to be described later.

  In this embodiment, the copy-forgery-inhibited pattern image forming unit 205 has a function of forming copy-forgery-inhibited pattern image data 1007 based on the embedded data 1005b (or the embedded data 1005b and the reduced print image data 1006), and further, a copy-forgery-inhibited pattern code described later. The copy-forgery-inhibited pattern data 1007 ′ has a function of forming copy-forgery-inhibited pattern image data 1007.

  In this embodiment, the control unit 200 ′ reads the device data 1004 from the data storage unit 300 based on a command from the host device 11 ′, and the host device via the I / O interface 111 or the network 41. 11 'is output.

  Although the embedded data generation unit 203 is not depicted in FIG. 7, this is not used in the description of this embodiment, and is simply omitted and actually exists.

  Although the extraction result determination unit 213 is illustrated in FIG. 7, the extraction result determination unit 213 does not operate in this embodiment.

  On the other hand, as shown in FIG. 7, the upper level apparatus 11 ′ is connected to the remote printing apparatus 1 via a wired or wireless network (for example, a LAN or the Internet) 41. The higher-level device 11 ′ functions as a digital watermark generation device that generates a digital watermark and also functions as a verification device that verifies the digital watermark.

  As shown in FIG. 7, such a higher-level device 11 ′ includes an embedded data generation unit 63, a tint block encoded data generation unit 65, compressed data, in addition to the components and functional means of the higher-level device 11 according to the second embodiment. A generation unit 67 is provided.

  The embedded data generation unit 63 is a functional unit similar to the embedded data generation unit 203 of the printing apparatus 1 shown in FIG. Here, the embedded data generation unit 63 performs the same operation as the embedded data generation unit 203 in the first embodiment.

  The copy-forgery-inhibited pattern encoded data generation unit 65 is based on the embedded data 1005b generated by the embedded data generation unit 63 (or, depending on the operation, the embedded data 1005b generated by the embedded data generation unit 63 and the print image forming unit 61 A copy-forgery-inhibited pattern image data 1007 is formed on the basis of the reduced print image data 1006 to be formed, and the copy-forgery-inhibited pattern image data 1007 is encoded to generate a copy-forgery-inhibited pattern encoded data 1007 ′. In order to represent the copy-forgery-inhibited pattern image data 1007 with a small amount of data, the copy-forgery-inhibited pattern encoded data 1007 ′ is a binary or multi-value representing the arrangement pattern of the embedded pixel data 1008a and 1008b in the copy-forgery-inhibited pattern image data 1007 as a bit arrangement. Bit data.

  The compressed data generation unit 67 is a functional unit that performs lossless compression of the print data 1001 and the tint block encoded data 1007 ′ as one data. Hereinafter, the data reversibly compressed by the compressed data generation unit 67 is referred to as compressed data 1031. By outputting the compressed data 1031 to the printing apparatus 1, the upper level apparatus 11 ′ can output data for generating the print image 1011 embedded with the digital watermark to the printing apparatus 1 with a small amount of data. it can. For lossless compression of data, for example, a method such as the Run-Length method or the Huffman method is used. Since these are well-known, detailed description is abbreviate | omitted here.

  The embedded data generation unit 63, the tint block encoded data generation unit 65, and the compressed data generation unit 67 together with the print image formation unit 61 constitute a watermark generation unit 60 that generates a digital watermark.

<Operation of printing device and host device>
Hereinafter, operations of the printing apparatus 1 and the host apparatus 11 ′ will be described. In this embodiment, it is assumed that the printer gives a print instruction for printing an image of a desired document by operating the input unit 15 of the host apparatus 11 ′.

  FIG. 8 is a diagram illustrating an operation flow of the printing apparatus and the host apparatus according to the third embodiment. FIG. 9 is an operation explanatory diagram of the printing apparatus and the host apparatus according to the third embodiment, and shows an example of an image formed in each step shown in FIG. 8 or an example of an image used.

  A printer operates the input unit 15 of the host device 11 'to give an instruction to print an image such as a document or a graphic. As a result, as shown in FIG. 8, the host device 11 'operates in the same manner as in the second embodiment in S501 to S503. That is, the processing unit 50 (specifically, the control unit 50 ′) of the host apparatus 11 ′ acquires a print instruction (S501), and based on the print instruction, documents, graphics, and the like to be printed on the print medium 31 are obtained. The print data 1001 (see FIGS. 7 and 9) is specified (S503). Then, the processing unit 50 (specifically, the control unit 50 ′) reads the specified print data 1001 from the data storage unit 80, and prints the print image forming unit 61, the embedded data generating unit 63, the compressed data generating unit 67, The data is output to the verification unit 73.

  Next, the print image forming unit 61 of the host apparatus 11 'forms print image data 1003 (see FIG. 9) based on the print data 1001 acquired from the data storage unit 80 (S601). At this time, the print image forming unit 61 first identifies the file extension of the print data 1001 and recognizes the file format. In this embodiment, it is assumed that the file extension of the print data 1001 is a code meaning a document file. In this case, the print image forming unit 61 recognizes the print data 1001 as a document file. The print image forming unit 61 forms print image data 1003 that is image data of a document image from the print data 1001 based on the recognized file format.

  Next, the embedded data generation unit 63 of the upper level device 11 ′ acquires device data 1004 (see FIGS. 7 and 9) from the data storage unit 300 of the printing device 1 via the network 41 and the I / O interface 91. (S603). At this time, the embedded data generation unit 63 outputs a command for instructing to output the device data 1004 to the printing device 1 via the network 41 or the I / O interface 91. In response to this, the control unit 200 ′ of the printing apparatus 1 reads out the device data 1004 from the data storage unit 300 of the printing apparatus 1 and outputs it to the upper level apparatus 11 ′. As a result, the embedded data generation unit 63 acquires the device data 1004 from the data storage unit 300 of the printing device 1.

  Next, the embedded data generation unit 63 of the upper level apparatus 11 ′ generates embedded data 1005 b (see FIGS. 7 and 9) based on the print data 1001 and the apparatus data 1004 (S 605). At this time, the embedded data generation unit 63 first acquires the print data 1001 from the data storage unit 80. For example, the embedded data generation unit 63 extracts one or more types of data used for the digital watermark from the print data 1001 and the device data 1004 acquired in step S603, or sets the data used for the digital watermark in advance. The tracking data 1005a (see FIG. 9) is generated by arranging according to the priorities, and the tracking data 1005a is encoded to generate embedded data 1005b. Thereafter, the embedded data generation unit 63 outputs the embedded data 1005b to the background pattern encoded data generation unit 65.

  Next, the print image forming unit 61 of the host apparatus 11 ′ reduces or compresses the print image data 1003 formed in S601 so as to be less than or equal to the amount of data that can be embedded as a digital watermark, and reduces the print image data 1006 ( 7 and 9) are formed (S607). For the compression of the print image data 1003, for example, a method such as MMR (Modified Modified Read Code), JBIG (Joint Bi-level Image experts Group), or MR (Modified Read Code) is used. Since these are well-known, detailed description is abbreviate | omitted here. Thereafter, the print image forming unit 61 outputs the reduced print image data 1006 to the background pattern encoded data generation unit 65.

  Next, the copy-forgery-inhibited pattern encoded data generation unit 65 of the upper level apparatus 11 'forms copy-forgery-inhibited pattern image data 1007 (see FIG. 9) based on the embedded data 1005b and the reduced print image data 1006 (S609). At this time, the tint block encoded data generation unit 65 first acquires the embedded data 1005b from the embedded data generation unit 63, and acquires the size data of the reduced print image data 1006 and the print image data 1003 from the print image forming unit 61. . Then, the tint block encoded data generation unit 65 synthesizes the embedded data 1005b and the reduced print image data 1006 so as to have the same size as the size of the print image data 1003, thereby forming the digital watermark tint block image data 1007. To do.

  Next, the background pattern encoded data generation unit 65 of the higher-level device 11 ′ generates background pattern encoded data 1007 ′ (see FIGS. 7 and 9) based on the background pattern image data 1007 (S 611). As described above, the background pattern encoded data 1007 ′ is a binary value that represents the array pattern of the embedded pixel data 1008a and 1008b in the background pattern image data 1007 as a bit sequence in order to represent the background pattern image data 1007 with a small amount of data. Or multi-valued bit data. Thereafter, the background pattern encoded data generation unit 65 outputs the background pattern encoded data 1007 ′ to the compressed data generation unit 67.

  Next, the compressed data generation unit 67 of the host device 11 'generates compressed data 1031 (see FIGS. 7 and 9) (S613). At this time, the compressed data generation unit 67 first acquires the print data 1001 from the data storage unit 80 and acquires the background pattern encoded data 1007 ′ from the background pattern encoded data generation unit 65. Then, the compressed data generation unit 67 reversibly compresses the print data 1001 and the tint block encoded data 1007 ′ as one data so that they can be decompressed using a method such as the Run-Length method or the Huffman method. Thus, compressed data 1031 is generated.

  Next, the compressed data generation unit 67 of the host apparatus 11 'outputs the compressed data 1031 to the printing apparatus 1 via the I / O interface 91 and the network 41 (S615).

  The processing unit 200 (specifically, the control unit 200 ′) of the printing apparatus 1 acquires the compressed data 1031 from the upper level apparatus 11 ′ via the network 41 or the I / O interface 111 (S 701). This compressed data 1031 is input to the compressed data decompression unit 200 a of the watermark embedding unit 600.

  Next, the compressed data decompression unit 200a of the printing apparatus 1 decompresses the compressed data 1031 to obtain the print data 1001 and the tint block encoded data 1007 '(S703). Thereafter, the compressed data decompressing unit 200a outputs the print data 1001 to the print image forming unit 201 and also outputs the tint block encoded data 1007 'to the tint block image forming unit 205 (see FIGS. 7 and 9).

  Next, the print image forming unit 201 of the printing apparatus 1 forms print image data 1003 (see FIG. 7 and FIG. 9) based on the print data 1001 as in S1003 of FIG. 5 (S705). Thereafter, the print image forming unit 201 outputs the print image data 1003 to the image composition unit 207.

  Next, the copy-forgery-inhibited pattern image forming unit 205 of the printing apparatus 1 forms copy-forgery-inhibited pattern image data 1007 (see FIGS. 7 and 9) based on the copy-forgery-inhibited pattern data 1007 '(S707). That is, the tint block image forming unit 205 reads the arrangement of bit data from the tint block encoded data 1007 ′, and arranges the image of the signal pattern corresponding to the bit data. In this way, the background pattern image forming unit 205 decodes the background pattern encoded data 1007 ′ to form the background pattern image data 1007. In this embodiment, the copy-forgery-inhibited pattern image data 1007 includes embedded data 1005b and reduced print image data 1006. Thereafter, the tint block image forming unit 205 outputs the tint block image data 1007 to the image composition unit 207.

  Next, the image composition unit 207 of the printing apparatus 1 composes the print image data 1003 and the copy-forgery-inhibited pattern image data 1007 to form composite image data 1009 (see FIGS. 7 and 9), as in S1009 of FIG. (S709). Thereafter, the image composition unit 207 outputs the composite image data 1009 to the printing unit 400.

  Next, the printing apparatus 1 operates in the same manner as in the second embodiment in S1011 to S1023. That is, first, the printing unit 400 of the printing apparatus 1 prints the print image 1011 on the print medium 31 based on the composite image data 1009 (S1011). Next, the reading unit 500 of the printing apparatus 1 reads the print image 1011 from the print medium 31 and acquires the read data 1021 (S1021). Then, similarly to the second embodiment, the watermark data extraction unit 211 of the printing apparatus 1 extracts the watermark data 1023 that is the electronic watermark copy-forgery-inhibited pattern image data embedded in the print image 1011 from the read data 1021 (S1023). In addition, after S1023, in Example 2, the process proceeds to S1025, but in this example, the process proceeds to S1032.

  Next, the watermark data extraction unit 211 of the printing apparatus 1 outputs the watermark data 1023 to the upper level apparatus 11 ′ via the I / O interface 111 and the network 41 (S 1032). The watermark data 1023 includes reduced print image data 1024 as with the watermark data 1023 of the second embodiment.

  The host apparatus 11 'operates in the same manner as in the second embodiment in S1033 to S1047.

  That is, first, the processing unit 50 (specifically, the control unit 50 ′) of the upper level apparatus 11 ′ acquires the watermark data 1023 from the printing apparatus 1 via the network 41 or the I / O interface 91 (S1033). . The watermark data 1023 acquired at this time is input to the data storage unit 80, the tracking data generation unit 71, the print image forming unit 61, and the verification unit 73 (see FIG. 7).

  Next, the processing unit 50 (specifically, the control unit 50 ′ or the verification unit 73) of the upper level apparatus 11 ′ stores the watermark data 1023 acquired from the printing apparatus 1 in the data storage unit 80 (S 1035).

  Next, the tracking data generation unit 71 of the host device 11 'extracts the embedded data 1025a from the watermark data 1023, decodes the embedded data 1025a, and generates the tracking data 1025b (S1037).

  Next, the print image forming unit 61 of the host apparatus 11 ′ extracts the reduced print image data 1024 from the watermark data 1023, enlarges the reduced print image data 1024 to the size before reduction, and forms the restored print image data 1026. (S1038).

  Next, the print image forming unit 61 of the host apparatus 11 'forms original print image data 1027 based on the print data 1001 output to the printing apparatus 1 in S1001 (S1039).

  Next, the verification unit 73 of the host apparatus 11 ′ compares the brightness value of the restored print image data 1026 and the brightness value of the original print image data 1027, and determines whether or not they match within a predetermined allowable range. Determination is made (S1043). That is, the verification unit 73 determines whether the difference between the luminance value of the restored print image data 1026 and the luminance value of the original print image data 1027 is smaller than a predetermined threshold value. As a result, the host apparatus 11 ′ can automatically detect fraudulent acts such as copying and falsification of the print image 1011. When the restored print image data 1026 and the original print image data 1027 match within a predetermined allowable range (that is, the difference between the brightness value of the restored print image data 1026 and the brightness value of the original print image data 1027 is a predetermined threshold value) Is smaller), the verification unit 73 of the host apparatus 11 ′ determines that “there was no fraudulent action on the print image 1011”. In this case, the process proceeds to S1045. On the other hand, when the restored print image data 1026 and the original print image data 1027 do not match within a predetermined allowable range (that is, the difference between the brightness value of the restored print image data 1026 and the brightness value of the original print image data 1027 is determined in advance. If the threshold value is larger than the threshold value, the verification unit 73 of the host device 11 ′ determines that “there was an illegal act on the print image 1011”. In this case, the process proceeds to S1047.

  When it is determined in S1043 that “the restored print image data 1026 and the original print image data 1027 match within a predetermined allowable range”, the verification unit 73 (or the control unit 50 ′) performs the tracking data 1025b and the restored print image. The image data 1026, the original print image data 1027, a display indicating that there is no fraud, and the like are displayed on the display 13 (S1045), and the printer is confirmed.

  On the other hand, when it is determined in S1043 that “the restored print image data 1026 and the original print image data 1027 do not match within a predetermined allowable range”, the verification unit 73 (or the control unit 50 ′) performs the tracking data 1025b or The restored print image data 1026, the original print image data 1027, an indication that there is an illegal act such as falsification, and the like are displayed on the display 13 (S1047), and the printer is confirmed.

  As described above, a series of operations of the printing apparatus 1 and the upper level apparatus 11 ′ are completed.

  Note that the printing apparatus 1 and the host apparatus 11 ′ according to this embodiment can also operate in the same manner as in the first or second embodiment.

  Further, in this embodiment, the host apparatus 11 ′ forms the compressed data 1031 in advance and stores it in the data storage unit 80. When there is a print instruction from the printer, the upper level device 11 ′ stores the compressed data 1031 in the data storage unit. It is also possible to read from 80 and output to the printing apparatus 1.

  The verification unit 73 of the host apparatus 11 ′ compares the brightness value of the restored print image data 1026 with the brightness value of the original print image data 1027, and verifies whether the print image 1011 has been cheated. In addition to the function, the embedded data 1005b generated in S605 is compared with the embedded data 1025a included in the watermark data 1023 acquired from the printing apparatus 1 in S1033, and whether the print image 1011 has been cheated. May have a function of verifying.

  As described above, according to this embodiment, the host apparatus 11 ′ generates a digital watermark (background pattern image data 1007) based on the print data 1001 and the apparatus data 1004. The host apparatus 11 ′ then encodes the digital watermark (background pattern image data 1007) to generate background pattern encoded data 1007 ′, and prints the compressed data 1031 based on the print data 1001 and the background pattern encoded data 1007 ′. Output to device 1. On the other hand, the printing apparatus 1 decompresses the compressed data 1031 to obtain the print data 1001 and the tint block encoded data 1007 ′, forms print image data 1003 based on the print data 1001, and also encodes the tint block encoded data 1007 ′. The copy-forgery-inhibited pattern image data 1007 is formed based on the print image 1011, and the print image 1011 in which the digital watermark is embedded is printed on the print medium 31 based on these. In this way, the printing apparatus 1 also supports a case where the remote host apparatus 11 'generates a digital watermark.

  Therefore, the printing apparatus 1 according to this embodiment has the same effect as that of the second embodiment (that is, the effect that “the security of the print image printed on the print medium can be improved as compared with the conventional technique”, “ In addition to the effect that the burden on the printer can be reduced and the effect that the host device 11 can detect fraudulent acts such as copying and falsification of the print image 1011), the host device 11 Even when a digital watermark is generated, an effect of being able to cope with this can be obtained.

  Further, the upper level apparatus 11 ′ according to this embodiment reversibly compresses the print data 1001 and the digital watermark copy-forgery-inhibited pattern encoded data 1007 ′ into one data as the compressed data 1031, and outputs the compressed data to the printing apparatus 1. Thereby, the upper level apparatus 11 ′ can output data for printing the watermarked print image 1011 (compressed data 1031 in this embodiment) to the printing apparatus 1 with a small amount of data. As a result, the host apparatus 11 ′ according to this embodiment can output data for printing the watermarked print image 1011 to the printing apparatus 1 in a short time, and efficiently print the print image 1011 on the printing apparatus 1. The effect that it can be made can be acquired.

  In the fourth embodiment, the printing apparatus 1 uses the network 41 to print the watermarked print image 1011 from a remote location (specifically, the host apparatus 11 ′ or a host apparatus 11 ″ described later) (this The embodiment is characterized in that when the compressed data 1031 or the composite image data 1009) is acquired, the print image 1011 is printed after verifying whether or not there is an illegal act such as falsification.

  According to this embodiment, the printer (or the administrator of the printer) can copy or tamper even when the printing apparatus 1 acquires data for printing the watermarked print image 1011 from a remote location. Thus, it is possible to prevent printing of the watermarked print image 1011 on which an illegal act such as the above has been performed.

<Configuration of printing device and host device>
Hereinafter, the configuration of the printing apparatus and its upper level apparatus will be described. FIG. 10 is a diagram illustrating configurations of a printing apparatus and a host apparatus according to the fourth embodiment. Here, a description will be given based on the third embodiment. Therefore, in the following, components that are different from the printing device 1 and the host device 11 ′ of the third embodiment will be described with emphasis, and the components that are common to the printing device 1 and the host device 11 ′ of the third embodiment and the same configuration. Explanation of elements is omitted. Note that among the higher-level devices 11 ′ that generate digital watermarks, there are those that directly output composite image data 1009 that is image data of a watermarked print image to the printing device 1. Hereinafter, a host device that directly outputs the composite image data 1009 to the printing apparatus 1 is referred to as a host device 11 ″ in order to distinguish it from a host device that does not directly output the composite image data 1009 to the printing apparatus 1. In FIG. The printing apparatus 1 is connected to the host apparatus 11 ′ and the host apparatus 11 ″ that generate digital watermarks via the network 41, but can also be connected to the host apparatus 11 that does not generate digital watermarks.

  As illustrated in FIG. 10, the printing apparatus 1 according to this embodiment includes a watermark data extraction unit 221 and a falsification detection unit 223 in addition to the components and functional units of the printing apparatus 1 according to the third embodiment.

  The watermark data extraction unit 221 is a functional unit that extracts digital watermark copy-forgery-inhibited pattern image data 1007 from the composite image data 1009.

  The falsification detection unit 223 compares the embedded data 1005b included in the copy-forgery-inhibited pattern image data 1007 extracted by the watermark data extraction unit 221 with the embedded data 1005b acquired from the higher-level device 11 ′ or the higher-level device 11 ″, and performs watermarking. Whether or not the data for printing the printed image 1011 (in this embodiment, the compressed data 1031 or the composite image data 1009) is correct (that is, the data for printing the watermarked printed image 1011 is fraudulent) The falsification detection unit 223 verifies that the data for printing the watermarked print image 1011 is incorrect (that is, for printing the watermarked print image 1011). If the data is fraudulent), stop the printing process.

  The watermark data extraction unit 221 and the falsification detection unit 223 operate on data for printing the watermarked print image 1011 (in this embodiment, compressed data 1031 or composite image data 1009) before printing the print image 1011. The watermark pre-verification unit 800 is configured to verify the presence or absence of fraud such as tampering. The printing apparatus 1 can prevent the watermarked print image 1011 subjected to an illegal act such as tampering from being printed by the watermark pre-verification unit 800.

  In this embodiment, the control unit 200 'can also output the device data 1004 to the host device 11 ".

  Although the embedded data generation unit 203 is not depicted in FIG. 10, this is not used in the description of this embodiment, and is simply omitted and actually exists.

  Although the extraction result determination unit 213 is illustrated in FIG. 10, the extraction result determination unit 213 does not operate in this embodiment.

  As shown in FIG. 10, the higher-level device 11 ′ according to this embodiment includes components and functional units of the higher-level device 11 ′ according to the third embodiment. The host device 11 'according to this embodiment performs the same operation as the host device 11' according to the third embodiment.

  The higher-level device 11 ′ functions as a digital watermark generation device that generates a digital watermark and also functions as a verification device that verifies the digital watermark.

  Further, as shown in FIG. 10, the upper level apparatus 11 ″ according to this embodiment includes a copy-forgery-inhibited pattern image forming unit 66 and an image synthesizing unit 68 in addition to the same components and functional means as the higher level apparatus 11 ′.

  The copy-forgery-inhibited pattern image forming unit 66 is a functional unit similar to the copy-forgery-inhibited pattern image forming unit 205 of the printing apparatus 1 shown in FIG. Here, it is assumed that the tint block image forming unit 66 performs the same operation as the tint block image forming unit 205 in the first embodiment.

  The image composition unit 68 is a functional unit similar to the image composition unit 207 of the printing apparatus 1 shown in FIG. Here, the image composition unit 68 performs the same operation as the image composition unit 207 in the first embodiment.

  Note that the higher-level device 11 ″ may be configured to have both the background pattern encoded data generation unit 65 and the compressed data generation unit 67 of the higher-level device 11 ′.

  The host apparatus 11 'functions as a digital watermark generation apparatus that generates a digital watermark, and also functions as a verification apparatus that verifies the digital watermark.

<Operation of printing device and host device>
Hereinafter, operations of the printing apparatus 1, the host apparatus 11 ′, and the host apparatus 11 ″ will be described. In this embodiment, the printer operates the input unit 15 of the host apparatus 11 ′ or the host apparatus 11 ″. In the following description, it is assumed that a print instruction for printing an image of a desired document has been issued.

  FIGS. 11A to 11C are flowcharts illustrating the operation flow of the printing apparatus and the host apparatus according to the fourth embodiment. FIG. 11A shows the operation of the host device 11 ′. 11-2 shows the operation of the printing apparatus 11 ″. FIG. 11-3 shows the printing apparatus 1 and the upper apparatus (the upper apparatus 11 ′ and the operation apparatus after the operation shown in FIGS. 11-1 and 11-2. The operation of the host device 11 ″ is also shown. FIGS. 12A and 12B are explanatory diagrams of operations of the printing apparatus and the host apparatus according to the fourth embodiment. Examples of images formed in the processes illustrated in FIGS. Or the example of the image used is shown. FIG. 12A mainly illustrates an operation example of the higher-level device 11 ′. FIG. 12-2 mainly shows an operation example of the host device 11 ″.

  The printer gives an instruction to print an image such as a document or a figure by operating the input unit 15 of the upper apparatus 11 ′ or the printing apparatus 11 ″. At this time, naturally, the upper apparatus 11 ′ and the upper apparatus 11 ″ The operation is different.

  As shown in FIG. 11A, the host device 11 'operates in the same manner as in the third embodiment in S501 to S613.

  That is, the processing unit 50 (specifically, the control unit 50 ′) of the host apparatus 11 ′ acquires a print instruction (S501), and based on the print instruction, documents, graphics, and the like to be printed on the print medium 31 are obtained. The print data 1001 (see FIGS. 10 and 12-1) is specified (S503). Then, the processing unit 50 (specifically, the control unit 50 ′) reads the specified print data 1001 from the data storage unit 80, and prints the print image forming unit 61, the embedded data generating unit 63, the compressed data generating unit 67, The data is output to the verification unit 73.

  Next, the print image forming unit 61 of the upper level apparatus 11 ′ forms print image data 1003 (see FIG. 12A) based on the print data 1001 acquired from the data storage unit 80 (S 601).

  Next, the embedded data generation unit 63 of the upper level apparatus 11 ′ receives the apparatus data 1004 (see FIGS. 10 and 12-1) from the data storage unit 300 of the printing apparatus 1 via the network 41 and the I / O interface 91. Obtain (S603). Then, the embedded data generation unit 63 generates tracking data 1005a (see FIG. 12-1) based on the print data 1001 and the device data 1004, encodes the tracking data 1005a, and embeds data 1005b (see FIG. 10). (Refer to FIG. 12A) is generated (S605).

  Next, the print image forming unit 61 of the host apparatus 11 ′ reduces the print image data 1003 formed in S601 to form reduced print image data 1006 (see FIGS. 10 and 12-1) (S607). . Then, the tint block encoded data generation unit 65 of the upper level apparatus 11 ′ forms tint block image data 1007 (see FIG. 12A) based on the embedded data 1005 b and the reduced print image data 1006 (S 609).

  Next, the background pattern encoded data generation unit 65 of the upper level apparatus 11 ′ generates background pattern encoded data 1007 ′ (see FIGS. 10 and 12-1) based on the background pattern image data 1007 (S 611). Then, the compressed data generation unit 67 of the host apparatus 11 ′ generates the compressed data 1031 (see FIGS. 10 and 12-1) by reversibly compressing the print data 1001 and the tint block encoded data 1007 ′ as one data. (S613).

  Thereafter, the compressed data generating unit 67 of the higher level apparatus 11 ′ outputs the compressed data 1031 to the printing apparatus 1 via the I / O interface 91 and the network 41, and the embedded data generating unit 63 of the higher level apparatus 11 ′. The embedded data 1005b corresponding to the compressed data 1031 is output to the printing apparatus 1 via the I / O interface 91 and the network 41 (S617).

  On the other hand, as shown in FIG. 11B, the upper apparatus 11 ″ operates in the same manner as the upper apparatus 11 ′ in S501 to S609.

  That is, the processing unit 50 (specifically, the control unit 50 ′) of the upper level apparatus 11 ″ obtains a print instruction (S501), and based on the print instruction, a document or a graphic to be printed on the print medium 31 is obtained. The print data 1001 is specified (S503), and the processing unit 50 (specifically, the control unit 50 ′) reads the specified print data 1001 from the data storage unit 80, and print image forming unit 61 or embedded data. The data is output to the generation unit 63, the image composition unit 68, and the verification unit 73.

  Next, the print image forming unit 61 of the host apparatus 11 ″ forms print image data 1003 based on the print data 1001 acquired from the data storage unit 80 (S601). Thereafter, the print image forming unit 61 Print image data 1003 is output to the image composition unit 68.

  Next, the embedded data generation unit 63 of the upper level apparatus 11 ″ acquires the device data 1004 from the data storage unit 300 of the printing apparatus 1 via the network 41 or the I / O interface 91 (S603). The generation unit 63 generates tracking data 1005a based on the print data 1001 and the device data 1004, encodes the tracking data 1005a, and generates embedded data 1005b (S605).

  Next, the print image forming unit 61 of the higher level apparatus 11 ″ reduces the print image data 1003 formed in S601 to form reduced print image data 1006 (S607). The converted data generation unit 65 forms the copy-forgery-inhibited pattern image data 1007 based on the embedded data 1005b and the reduced print image data 1006 (S609). Thereafter, the tint block encoded data generation unit 65 outputs the tint block image data 1007 to the image composition unit 68.

  Next, the image synthesizing unit 68 of the host apparatus 11 ″ synthesizes the print image data 1003 acquired from the image forming unit 61 and the copy-forgery-inhibited pattern image data 1007 acquired from the copy-forgery-inhibited pattern image forming unit 66 to generate composite image data 1009 (FIG. 12-2) (S621) At this time, the image composition unit 68 generates the print image data 1003 and the copy-forgery-inhibited pattern image data 1007 in the same manner as the image composition unit 207 of the printing apparatus 1 shown in FIG. The composite image data 1009 is formed by combining.

  Thereafter, the image composition unit 68 of the host apparatus 11 ″ outputs the composite image data 1009 to the printing apparatus 1 via the I / O interface 91 and the network 41, and the embedded data generation unit 63 of the host apparatus 11 ″. Then, the embedded data 1005b corresponding to the composite image data 1009 is output to the printing apparatus 1 via the I / O interface 91 and the network 41 (S623).

  The processing unit 200 (specifically, the control unit 200 ′) of the printing apparatus 1 acquires data from the upper apparatus 11 ′ or the upper apparatus 11 ″ via the network 41 or the I / O interface 111 (S631). If the data acquired at this time is data output from the host device 11 ′, the data is a combination of the compressed data 1031 and the embedded data 1005b. If the data is output from the host device 11 ″, the composite image is obtained. This data is a combination of the data 1009 and the embedded data 1005b.

  The processing unit 200 (specifically, the control unit 200 ') of the printing apparatus 1 determines whether or not the acquired data is a combination of the compressed data 1031 and the embedded data 1005b (S633). At this time, when the acquired data is a combination of the compressed data 1031 and the embedded data 1005b, the control unit 200 ′ outputs the compressed data 1031 to the compressed data decompressing unit 200a and detects the embedded data 1005b for falsification. Output to the unit 223. In this case, the process proceeds to S703. On the other hand, when the acquired data is not data obtained by combining the compressed data 1031 and the embedded data 1005b, the control unit 200 ′ outputs the composite image data 1009 to the watermark data extracting unit 221 and the embedded data 1005b as the falsification detecting unit. To 223. In this case, the process proceeds to S711.

  If the data acquired in S633 is a combination of the compressed data 1031 and the embedded data 1005b, the printing apparatus 1 operates in the same manner as in the third embodiment in S705 to S709.

  That is, first, the compressed data decompression unit 200a of the printing apparatus 1 decompresses the compressed data 1031 to obtain the print data 1001 and the tint block encoded data 1007 '(S703). Thereafter, the compressed data decompression unit 200a outputs the print data 1001 to the print image forming unit 201 and also outputs the tint block encoded data 1007 'to the tint block image forming unit 205 (see FIGS. 10 and 12-1).

  Next, the print image forming unit 201 of the printing apparatus 1 forms print image data 1003 (see FIGS. 10 and 12-1) based on the print data 1001 (S705). Thereafter, the print image forming unit 201 outputs the print image data 1003 to the image composition unit 207.

  Next, the copy-forgery-inhibited pattern image forming unit 205 of the printing apparatus 1 forms copy-forgery-inhibited pattern image data 1007 (see FIGS. 10 and 12-1) based on the copy-forgery-inhibited pattern encoded data 1007 '(S707). In this embodiment, the copy-forgery-inhibited pattern image data 1007 includes embedded data 1005b and reduced print image data 1006. Thereafter, the tint block image forming unit 205 outputs the tint block image data 1007 to the image composition unit 207.

  Then, the image composition unit 207 of the printing apparatus 1 composes the print image data 1003 and the copy-forgery-inhibited pattern image data 1007 to form composite image data 1009 (see FIGS. 10 and 12-1) (S709). Thereafter, the image composition unit 207 outputs the composite image data 1009 to the watermark data extraction unit 221 of the watermark pre-verification unit 800.

  After S709, the watermark data extraction unit 221 of the printing apparatus 1 acquires the composite image data 1009 from the image composition unit 207, and extracts the tint block image data 1007 from the composite image data 1009 (S711). Alternatively, when the data acquired in step S633 is not a combination of the compressed data 1031 and the embedded data 1005b, the watermark data extraction unit 221 of the printing apparatus 1 uses the combined image data 1009 output from the host apparatus 11 ″. Acquired and extracts the copy-forgery-inhibited pattern image data 1007 from the composite image data 1009. Thereafter, the watermark data extraction unit 221 outputs the copy-forgery-inhibited pattern image data 1007 and the composite image data 1009 to the falsification detection unit 223.

  Next, the falsification detection unit 223 of the printing apparatus 1 acquires the copy-forgery-inhibited pattern image data 1007 and the composite image data 1009 from the watermark data extraction unit 221, and extracts the embedded data 1005b from the copy-forgery-inhibited pattern image data 1007 (S713).

  Next, the falsification detection unit 223 of the printing apparatus 1 acquires the embedded data 1005b output from the upper apparatus 11 ″, and is extracted from the tint block image data 1007 in the embedded data 1005b and S713 output from the upper apparatus 11 ″. The embedded data 1005b is compared to determine whether or not they match. As a result, the falsification detection unit 223 of the printing apparatus 1 determines whether the data for printing the watermarked print image 1011 (in this embodiment, the compressed data 1031 or the composite image data 1009) is correct (that is, the watermarked image is included). It is determined whether or not fraudulent acts have been applied to the data for printing the print image 1011 (S715).

  At this time, if the two match, the falsification detecting unit 223 indicates that “the data for printing the watermarked print image 1011 is correct (that is, the data for printing the watermarked print image 1011 is improperly acted on). Not)). Thereafter, the falsification detection unit 223 outputs the composite image data 1009 to the printing unit 400. In this case, the process proceeds to S1011.

  On the other hand, when the two do not match, the falsification detection unit 223 indicates that the data for printing the watermarked print image 1011 is incorrect (that is, the data for printing the watermarked print image 1011 has an illegal act. It is determined). In this case, the process proceeds to S1081.

  If it is determined in S715 that “the data for printing the watermarked print image 1011 is correct”, the printing apparatus 1 operates in the same manner as in the third embodiment in S1011 to S1032.

  That is, first, the printing unit 400 of the printing apparatus 1 prints the print image 1011 on the print medium 31 based on the composite image data 1009 (S1011). Next, the reading unit 500 of the printing apparatus 1 reads the print image 1011 from the print medium 31 and acquires the read data 1021 (S1021). Next, the watermark data extraction unit 211 of the printing apparatus 1 extracts watermark data 1023, which is digital watermark copy-forgery-inhibited pattern image data embedded in the print image 1011 from the read data 1021 (S1023). Then, the watermark data extraction unit 211 of the printing apparatus 1 outputs the watermark data 1023 to the upper level apparatus 11 ′ via the I / O interface 111 and the network 41 (S 1032). The watermark data 1023 includes reduced print image data 1024.

  The host device 11 'operates in the same manner as in the third embodiment in S1033 to S1047.

  That is, first, the processing unit 50 (specifically, the control unit 50 ′) of the upper level apparatus 11 ′ acquires the watermark data 1023 from the printing apparatus 1 via the network 41 or the I / O interface 91 (S1033). . The watermark data 1023 acquired at this time is input to the data storage unit 80, the tracking data generation unit 71, the print image forming unit 61, and the verification unit 73 (see FIG. 10).

  Next, the processing unit 50 (specifically, the control unit 50 ′ or the verification unit 73) of the upper level apparatus 11 ′ stores the watermark data 1023 acquired from the printing apparatus 1 in the data storage unit 80 (S 1035).

  Next, the tracking data generation unit 71 of the host device 11 'extracts the embedded data 1025a from the watermark data 1023, decodes the embedded data 1025a, and generates the tracking data 1025b (S1037).

  Next, the print image forming unit 61 of the host apparatus 11 ′ extracts the reduced print image data 1024 from the watermark data 1023, enlarges the reduced print image data 1024 to the size before reduction, and forms the restored print image data 1026. (S1038).

  Next, the print image forming unit 61 of the host apparatus 11 'forms original print image data 1027 based on the print data 1001 output to the printing apparatus 1 in S1001 (S1039).

  Next, the verification unit 73 of the host apparatus 11 ′ compares the brightness value of the restored print image data 1026 and the brightness value of the original print image data 1027, and determines whether or not they match within a predetermined allowable range. Determination is made (S1043).

  When it is determined in S1043 that “the restored print image data 1026 and the original print image data 1027 match within a predetermined allowable range”, the verification unit 73 (or the control unit 50 ′) performs the tracking data 1025b and the restored print image. The image data 1026, the original print image data 1027, a display indicating that there is no fraud, and the like are displayed on the display 13 (S1045), and the printer is confirmed.

  On the other hand, when it is determined in S1043 that “the restored print image data 1026 and the original print image data 1027 do not match within a predetermined allowable range”, the verification unit 73 (or the control unit 50 ′) performs the tracking data 1025b or Display that there is a fraudulent act such as restored print image data 1026, original print image data 1027, falsification (or display that there is some error including a print error), and others are displayed on the display 13 (S1047) Let the printer check these.

  When it is determined in the above-described S715 that “the data for printing the watermarked print image 1011 is correct”, the falsification detection unit 223 (or the control unit 200 ′) determines the error data or the background pattern extracted in S711. The image data 1007 and other data are output via the I / O interface 111 and the network 41 to the upper apparatus 11 ′ or the upper apparatus 11 ″ that has output the data for printing the watermarked print image 1011 (S1081). Then, the falsification detection unit 223 (or the control unit 200 ′) stops the printing process (S1082).

  The processing unit 50 of the upper apparatus 11 ′ or the upper apparatus 11 ″ that has output the data for printing the watermarked print image 1011 receives error data or a copy-forgery-inhibited pattern image from the printing apparatus 1 via the network 41 or the I / O interface 91. The data 1007 is acquired (S1083), and the upper device that has output the data for printing the watermarked print image 1011 will be described as the upper device 11'.The error data and the copy-forgery-inhibited pattern image data 1007 acquired at this time are described below. The data storage unit 80 (or the control unit 50 ′) and the tracking data generation unit 71 are input (see FIG. 10).

  Next, the processing unit 50 (specifically, the control unit 50 ′) of the upper level apparatus 11 ′ stores the error data and the copy-forgery-inhibited pattern image data 1007 acquired from the printing apparatus 1 in the data storage unit 80 (S 1085). As a result, the error data and the copy-forgery-inhibited pattern image data 1007 are stored in the data storage unit 80 of the higher-level device 11 ′.

  Next, the tracking data generation unit 71 of the host apparatus 11 ′ extracts the embedded data 1005b from the copy-forgery-inhibited pattern image data 1007 acquired from the printing apparatus 1, and decodes the embedded data 1005b to generate the tracking data 1005a (S1087). .

  Next, the print image forming unit 61 of the host apparatus 11 ′ extracts the reduced print image data 1006 from the copy-forgery-inhibited pattern image data 1007 acquired from the printing apparatus 1, and expands the reduced print image data 1006 to the size before reduction. Restored print image data 1026 is formed (S1088).

  Next, the print image forming unit 61 of the host apparatus 11 ′ reads the print data 1001 specified in S503 from the data storage unit 80, and forms the original print image data 1027 based on the read print data 1001 (S1089). .

  Next, the processing unit 50 (specifically, the control unit 50 ′) of the host apparatus 11 displays an error display, the tracking data 1005a generated in S1087, the original print image data 1027, and others on the display 13. (S1091), these are confirmed by the printer. The printer (or the administrator of the printer) browses the screen displayed on the display 13 and checks the data displayed on the screen to detect fraudulent acts such as copying or falsification of the print image 1011. be able to. The printer who has confirmed the display of the error causes the printing apparatus 1 to print again, prints to another printing apparatus (not shown), or takes other measures depending on the situation. At this time, the printer stores or discards the print medium 31 on which the print image 1011 is printed, depending on the situation.

  As described above, a series of operations of the printing apparatus 1 and the upper level apparatus 11 ′ are completed.

  Note that the printing apparatus 1, the host apparatus 11 ′, and the host apparatus 11 ″ according to this embodiment can also operate in the same manner as in the first or second embodiment.

  Further, the host device 11 ′ forms the compressed data 1031 in advance and then stores it in the data storage unit 80. When there is a print instruction from the printer, the host device 11 ′ reads the compressed data 1031 from the data storage unit 80. It can also be output to the printing apparatus 1.

  In addition, the host device 11 ″ previously forms the composite image data 1009 and stores it in the data storage unit 80. When the printer issues a print instruction, the host device 11 ″ receives the composite image data 1009 from the data storage unit 80. It can also be read and output to the printing apparatus 1.

  Further, the verification unit 73 of the upper level apparatus 11 ″ compares the brightness value of the restored print image data 1026 and the brightness value of the original print image data 1027 to verify whether the print image 1011 has been cheated. In addition to the function, the embedded data 1005b generated in S605 is compared with the embedded data 1025a included in the watermark data 1023 acquired from the printing apparatus 1 in S1033, and whether the print image 1011 has been cheated. May have a function of verifying.

  In this embodiment, the host apparatus 11 ′ or the host apparatus 11 ″ embeds the data for printing the watermarked print image 1011 (here, the compressed data 1031 or the composite image data 1009) in advance. The data 1005b is output to the printing apparatus 1. Then, the falsification detection unit 223 of the watermark pre-verification unit 800 of the printing apparatus 1 uses the embedded data 1005b output from the upper apparatus 11 ′ or the upper apparatus 11 ″ and the background pattern in S713. By comparing with the embedded data 1005b extracted from the image data 1007, it is determined whether or not the data for printing the watermarked print image 1011 is correct. However, the upper apparatus 11 ′ or the upper apparatus 11 ″ may output reduced print image data 1006 to the printing apparatus 1 instead of the embedded data 1005 b.

  In this case, the falsification detection unit 223 of the watermark pre-verification unit 800 of the printing apparatus 1 uses, as the data for printing the watermarked print image 1011, for example, the reduced print image data 1006 and the compressed data 1031 from the upper level apparatus 11 ′. Will get. At this time, the falsification detection unit 223 first extracts the copy-forgery-inhibited pattern image data 1007 from the compressed data 1031, and then extracts reduced print image data 1006 from the copy-forgery-inhibited pattern image data 1007. Then, the falsification detection unit 223 compares the luminance value of the reduced print image data 1006 acquired from the host apparatus 11 ′ with the luminance value of the reduced print image data 1006 extracted from the copy-forgery-inhibited pattern image data 1007. At this time, when the difference between the two luminance values is equal to or smaller than a predetermined threshold value, the falsification detection unit 223 determines that the data for printing the watermarked print image 1011 is correct. On the other hand, when the difference between the luminance values is larger than a certain threshold value, the falsification detection unit 223 determines that the data for printing the watermarked print image 1011 is incorrect, and stops the printing process. In this way, the falsification detection unit 223 of the printing apparatus 1 determines whether the data for printing the watermarked print image 1011 is correct.

  Alternatively, the falsification detection unit 223 of the watermark pre-verification unit 800 of the printing apparatus 1 uses, as the data for printing the watermarked print image 1011, for example, the reduced print image data 1006 and the composite image data 1009 from the upper level apparatus 11 ″. At this time, the falsification detection unit 223 first extracts the copy-forgery-inhibited pattern image data 1007 from the composite image data 1009, and then extracts reduced print image data 1006 from the copy-forgery-inhibited pattern image data 1007. The falsification detection unit 223 compares the brightness value of the reduced print image data 1006 acquired from the host apparatus 11 ″ with the brightness value of the reduced print image data 1006 extracted from the copy-forgery-inhibited pattern image data 1007. At this time, when the difference between the two luminance values is equal to or smaller than a predetermined threshold value, the falsification detection unit 223 determines that the data for printing the watermarked print image 1011 is correct. On the other hand, when the difference between the luminance values is larger than a certain threshold value, the falsification detection unit 223 determines that the data for printing the watermarked print image 1011 is incorrect, and stops the printing process. In this way, the falsification detection unit 223 of the printing apparatus 1 determines whether the data for printing the watermarked print image 1011 is correct.

  The printing apparatus 1 according to this embodiment has the same effect as that of the third embodiment (that is, the effect that “the security of a print image printed on a print medium can be improved as compared with the conventional technique”, “the printer The effect that “the higher-level device 11 can detect fraudulent acts such as copying and falsification of the print image 1011”, and “the higher-level device 11 has generated a digital watermark.” Even in this case, it is possible to cope with this ”.

  Further, since the printing apparatus 1 according to this embodiment verifies the presence or absence of fraud before printing processing, data for printing a watermarked print image 1011 from a remote location (in this embodiment, compressed data 1031 or Even when the composite image data 1009) is acquired, it is possible to obtain an effect that it is possible to prevent printing of the watermarked print image 1011 subjected to an illegal act such as tampering. In the printing apparatus 1, even when the host apparatus 11 ′ temporarily stores the compressed data 1031 in the data storage unit 80, the host apparatus 11 ″ temporarily stores the composite image data 1009 in the data storage unit 80. Even in this case, it is possible to obtain an effect that it is possible to prevent printing of the watermarked print image 1011 on which an illegal act such as tampering has been performed, and the printing apparatus 1 according to this embodiment is in an early stage. Since fraudulent acts are detected in step 1, unnecessary steps (ie, S1011 to S1023 ("print processing" to "watermark data extraction")) when fraudulent acts are detected can be omitted, and fraudulent acts are detected. In this case, the processing speed can be improved.

  Further, as in the third embodiment, the host apparatus 11 ′ according to the present embodiment reversibly compresses the print data 1001 and the digital watermark copy-forgery-inhibited pattern encoded data 1007 ′ into one piece of data as compressed data. Since the data is output, data for printing the watermarked print image 1011 can be output to the printing apparatus 1 in a short time, and the printing apparatus 1011 can be efficiently printed. it can.

  The present invention is not limited to the above-described embodiments, and various applications and modifications can be considered without departing from the gist of the present invention.

  For example, according to the present invention, the watermark embedding unit 600 of the printing apparatus 1 includes the copyright data and falsification detection data of the print image in the embedded data embedded in the print image, so that the watermark detection unit 700 of the printing apparatus 1 can print the print medium. Thus, copyright data and falsification detection data of the print image can be extracted as watermark data. In this case, the printing apparatus 1 can easily detect fraudulent acts such as copying or falsification of the print medium.

  In the third or fourth embodiment, the host apparatus 11 ′ generates the compressed data 1031 in advance and stores it in the data storage unit 80, and stores the compressed data 1031 in response to a print instruction from the printer. The data may be read from the unit 80 and output to the printing apparatus 1.

  Further, in the fourth embodiment, the host apparatus 11 ″ forms the composite image data 1009 in advance and stores it in the data storage unit 80, and stores the composite image data 1009 when the printer gives a print instruction. The data may be read from the unit 80 and output to the printing apparatus 1.

1 is a diagram illustrating a configuration of a printing apparatus and a host apparatus according to Embodiment 1. FIG. FIG. 6 is a diagram illustrating an operation flow of the printing apparatus and the host apparatus according to the first embodiment. FIG. 6 is an operation explanatory diagram of the printing apparatus and the host apparatus according to the first embodiment. FIG. 10 is a diagram illustrating a configuration of a printing apparatus and a host apparatus according to a second embodiment. FIG. 10 is a diagram illustrating an operation flow of a printing apparatus and a host apparatus according to a second embodiment. FIG. 9 is an operation explanatory diagram of a printing apparatus and a host apparatus according to a second embodiment. FIG. 10 is a diagram illustrating a configuration of a printing apparatus and a host apparatus according to a third embodiment. FIG. 10 is a diagram illustrating an operation flow of a printing apparatus and a host apparatus according to a third embodiment. FIG. 9 is an operation explanatory diagram of a printing apparatus and a host apparatus according to a third embodiment. FIG. 10 illustrates a configuration of a printing apparatus and a host apparatus according to a fourth embodiment. FIG. 10A is a diagram (1) illustrating an operation flow of a printing apparatus and a host apparatus according to a fourth embodiment. FIG. 10B is a diagram (2) illustrating an operation flow of the printing apparatus and the host apparatus according to the fourth embodiment. FIG. 10C is a diagram (3) illustrating an operation flow of the printing apparatus and the host apparatus according to the fourth embodiment. FIG. 10 is an operation explanatory diagram (1) of a printing apparatus and a host apparatus according to a fourth embodiment. FIG. 10 is an operation explanatory diagram (2) of the printing apparatus and the host apparatus according to the fourth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printing apparatus 11 ... Host apparatus (PC, server)
31 ... Print medium 110 ... Data acquisition unit 200 ... Processing unit (CPU)
DESCRIPTION OF SYMBOLS 201 ... Print image formation part 203 ... Embedded data generation part 205 ... Copy-forgery-inhibited pattern image formation part 207 ... Image composition part 211 ... Watermark data extraction part 213 ... Extraction result determination part 300 ... Data storage part (RAM)
400 ... printing unit 500 ... reading unit 600 ... watermark embedding unit 700 ... watermark detection unit

Claims (14)

A data acquisition unit for acquiring print data for printing an image on a print medium from the outside;
A print image forming unit that forms print image data that is image data of a print image based on the print data acquired by the data acquisition unit;
An embedded data generation unit that generates embedded data to be embedded in a print image as a digital watermark based on the print data acquired by the data acquisition unit and device data that is unique to a printing device or a printing situation When,
Based on the embedded data generated by the embedded data generation unit, a tint block image forming unit that forms tint block image data that is image data of a tint block image of a digital watermark;
A composite image which is image data of a watermarked print image in which a digital watermark is embedded by combining the print image data formed by the print image forming unit and the copy-forgery-inhibited pattern image data formed by the copy-forgery-inhibited pattern image forming unit. An image composition unit for forming data;
A printing unit that prints a composite image, which is a watermarked print image embedded with a digital watermark, on the print medium based on the composite image data formed by the image composition unit;
A reading unit that reads the composite image data from the print medium and obtains read data that is a read result of the composite image data;
A watermark data extraction unit that extracts the copy-forgery-inhibited pattern image data from the read data acquired by the reading unit and acquires watermark data that is an extraction result of the copy-forgery-inhibited pattern image data;
The embedded data generated by the embedded data generation unit and the embedded data included in the watermark data extracted by the watermark data extraction unit are compared, and it is determined whether or not they match within a predetermined allowable range An extraction result determination unit that determines whether or not the print image is correctly printed on the print medium,
The extraction result determination unit
When the embedded data and the embedded data included in the watermark data match within a predetermined allowable range, it is determined that the composite image is correctly printed on the print medium, and the watermark data is transferred to the printing device. To the host device that outputs the print command to
When the embedded data and the embedded data included in the watermark data do not match within a predetermined allowable range, it is determined that the composite image is not correctly printed on the print medium, and error data and the watermark data are A printing apparatus that outputs to the host apparatus. A data acquisition unit for acquiring print data for printing an image on a print medium from the outside;
A print image forming unit that forms print image data that is image data of a print image based on the print data acquired by the data acquisition unit;
An embedded data generation unit that generates embedded data to be embedded in a print image as a digital watermark based on the print data acquired by the data acquisition unit and device data that is unique to a printing device or a printing situation When,
Based on the embedded data generated by the embedded data generation unit, a tint block image forming unit that forms tint block image data that is image data of a tint block image of a digital watermark;
A composite image which is image data of a watermarked print image in which a digital watermark is embedded by combining the print image data formed by the print image forming unit and the copy-forgery-inhibited pattern image data formed by the copy-forgery-inhibited pattern image forming unit. An image composition unit for forming data;
A print unit that prints a composite image, which is a watermarked print image embedded with a digital watermark, on the print medium based on the composite image data formed by the image composition unit;
When the data acquisition unit acquires document data as the print data,
The print image forming unit recognizes a file format of the document data from an extension attached to a file name of the document data, and forms the print image data based on the recognized file format. Printing device to do. A data acquisition unit for acquiring print data for printing an image on a print medium from the outside;
A print image forming unit that forms print image data that is image data of a print image based on the print data acquired by the data acquisition unit;
An embedded data generation unit that generates embedded data to be embedded in a print image as a digital watermark based on the print data acquired by the data acquisition unit and device data that is unique to a printing device or a printing situation When,
Based on the embedded data generated by the embedded data generation unit, a tint block image forming unit that forms tint block image data that is image data of a tint block image of a digital watermark;
A composite image which is image data of a watermarked print image in which a digital watermark is embedded by combining the print image data formed by the print image forming unit and the copy-forgery-inhibited pattern image data formed by the copy-forgery-inhibited pattern image forming unit. An image composition unit for forming data;
A print unit that prints a composite image, which is a watermarked print image embedded with a digital watermark, on the print medium based on the composite image data formed by the image composition unit;
When the data acquisition unit acquires document data with a designated address for specifying a file format as the print data,
The print image forming unit recognizes the designated address data attached to the document data, and acquires the file format of the document data from a data storage unit inside the printing apparatus based on the recognized designated address data. Then, the printing image data is formed based on the acquired file format. A data acquisition unit for acquiring print data for printing an image on a print medium from the outside;
A print image forming unit that forms print image data that is image data of a print image based on the print data acquired by the data acquisition unit;
An embedded data generation unit that generates embedded data to be embedded in a print image as a digital watermark based on the print data acquired by the data acquisition unit and device data that is unique to a printing device or a printing situation When,
Based on the embedded data generated by the embedded data generation unit, a tint block image forming unit that forms tint block image data that is image data of a tint block image of a digital watermark;
A composite image which is image data of a watermarked print image in which a digital watermark is embedded by combining the print image data formed by the print image forming unit and the copy-forgery-inhibited pattern image data formed by the copy-forgery-inhibited pattern image forming unit. An image composition unit for forming data;
A print unit that prints a composite image, which is a watermarked print image embedded with a digital watermark, on the print medium based on the composite image data formed by the image composition unit;
The copy-forgery-inhibited pattern image forming unit is defined as an array pattern that means a value of 0 bits based on the embedded data so as to be the same size as the size of the print image data formed by the print image forming unit. By arranging invisible embedded pixel data and invisible embedded pixel data defined as an array pattern that means a 1-bit value, image data that forms the base of the copy-forgery-inhibited pattern image data is formed, and the image that becomes the base The copy-forgery-inhibited pattern image data is formed by applying data to reduced print image data formed by reducing the print image data so that the print image data can be embedded as a digital watermark. apparatus. A data acquisition unit for acquiring print data for printing an image on a print medium from the outside;
When the data acquisition unit acquires compressed data obtained by combining a plurality of types of data from a host device that outputs a print command to the printing device, the compressed data is decompressed, and the print data and the watermark of the electronic watermark are displayed. A compressed data decompression unit that obtains tint block encoded data obtained by encoding tint block image data that is image data of an image;
A print image forming unit that forms print image data that is image data of a print image based on the print data acquired by the compressed data decompression unit;
A copy-forgery-inhibited pattern image forming unit that forms the copy-forgery-inhibited pattern image data based on the copy-forgery-inhibited pattern encoded data acquired by the compressed data decompression unit;
A composite image which is image data of a watermarked print image in which a digital watermark is embedded by combining the print image data formed by the print image forming unit and the copy-forgery-inhibited pattern image data formed by the copy-forgery-inhibited pattern image forming unit. An image composition unit for forming data;
A printing apparatus comprising: a printing unit configured to print a composite image, which is a watermarked print image embedded with a digital watermark, on the print medium based on the composite image data formed by the image composition unit. The printing apparatus according to claim 5 , wherein
The compressed data acquired from the host device is generated by reversibly compressing a plurality of types of data by a Run-Length method or a Huffman method. A data acquisition unit for acquiring print data for printing an image on a print medium from the outside;
A print image forming unit that forms print image data that is image data of a print image based on the print data acquired by the data acquisition unit;
An embedded data generation unit that generates embedded data to be embedded in a print image as a digital watermark based on the print data acquired by the data acquisition unit and device data that is unique to a printing device or a printing situation When,
Based on the embedded data generated by the embedded data generation unit, a tint block image forming unit that forms tint block image data that is image data of a tint block image of a digital watermark;
A composite image which is image data of a watermarked print image in which a digital watermark is embedded by combining the print image data formed by the print image forming unit and the copy-forgery-inhibited pattern image data formed by the copy-forgery-inhibited pattern image forming unit. An image composition unit for forming data;
A printing unit that prints a composite image, which is a watermarked print image embedded with a digital watermark, on the print medium based on the composite image data formed by the image composition unit;
A watermark pre-verification unit that verifies the presence or absence of fraud on the composite image data before the printing unit performs a printing process based on the composite image data;
The watermark pre-verification unit
The printing device is generated based on the embedded data embedded in the print image as a digital watermark from the host device that outputs a print command to the printing device, and is the basis of the composite image data. When compressed data obtained by combining a plurality of types of data is acquired, embedded data is extracted from the compressed data, the extracted embedded data is compared with the embedded data acquired from the host device, and both are predetermined. The printing apparatus determines that there has been an illegal act on the composite image data when they do not match within the allowable range. A data acquisition unit for acquiring print data for printing an image on a print medium from the outside;
When the data acquisition unit acquires compressed data obtained by combining a plurality of types of data from a host device that outputs a print command to the printing device, the compressed data is decompressed, and the print data and the watermark of the electronic watermark are displayed. A compressed data decompression unit that obtains tint block encoded data obtained by encoding tint block image data that is image data of an image;
A print image forming unit that forms print image data that is image data of a print image based on the print data acquired by the compressed data decompression unit;
A copy-forgery-inhibited pattern image forming unit that forms the copy-forgery-inhibited pattern image data based on the copy-forgery-inhibited pattern encoded data acquired by the compressed data decompression unit;
A composite image which is image data of a watermarked print image in which a digital watermark is embedded by combining the print image data formed by the print image forming unit and the copy-forgery-inhibited pattern image data formed by the copy-forgery-inhibited pattern image forming unit. An image composition unit for forming data;
A printing unit that prints a composite image, which is a watermarked print image embedded with a digital watermark, on the print medium based on the composite image data formed by the image composition unit;
A watermark pre-verification unit that verifies the presence or absence of fraud on the composite image data before the printing unit performs a printing process based on the composite image data;
The watermark pre-verification unit
The printing device is generated based on the embedded data embedded in the print image as a digital watermark from the host device that outputs a print command to the printing device, and is the basis of the composite image data. When compressed data obtained by combining a plurality of types of data is acquired, embedded data is extracted from the compressed data, the extracted embedded data is compared with the embedded data acquired from the host device, and both are predetermined. The printing apparatus determines that there has been an illegal act on the composite image data when they do not match within the allowable range. A data acquisition unit for acquiring print data for printing an image on a print medium from the outside;
A print image forming unit that forms print image data that is image data of a print image based on the print data acquired by the data acquisition unit;
An embedded data generation unit that generates embedded data to be embedded in a print image as a digital watermark based on the print data acquired by the data acquisition unit and device data that is unique to a printing device or a printing situation When,
Based on the embedded data generated by the embedded data generation unit, a tint block image forming unit that forms tint block image data that is image data of a tint block image of a digital watermark;
A composite image which is image data of a watermarked print image in which a digital watermark is embedded by combining the print image data formed by the print image forming unit and the copy-forgery-inhibited pattern image data formed by the copy-forgery-inhibited pattern image forming unit. An image composition unit for forming data;
A printing unit that prints a composite image, which is a watermarked print image embedded with a digital watermark, on the print medium based on the composite image data formed by the image composition unit;
A watermark pre-verification unit that verifies the presence or absence of fraud on the composite image data before the printing unit performs a printing process based on the composite image data;
The watermark pre-verification unit
When the printing device acquires from the host device that outputs a print command to the printing device, embedded data embedded in a print image as a digital watermark, and the composite image data generated based on the embedded data, Extracting embedded data from the composite image data, comparing the extracted embedded data with the embedded data acquired from the host device, and if the two do not match within a predetermined allowable range, A printing apparatus characterized by determining that an action has occurred. A data acquisition unit for acquiring print data for printing an image on a print medium from the outside;
When the data acquisition unit acquires compressed data obtained by combining a plurality of types of data from a host device that outputs a print command to the printing device, the compressed data is decompressed, and the print data and the watermark of the electronic watermark are displayed. A compressed data decompression unit that obtains tint block encoded data obtained by encoding tint block image data that is image data of an image;
A print image forming unit that forms print image data that is image data of a print image based on the print data acquired by the compressed data decompression unit;
A copy-forgery-inhibited pattern image forming unit that forms the copy-forgery-inhibited pattern image data based on the copy-forgery-inhibited pattern encoded data acquired by the compressed data decompression unit;
A composite image which is image data of a watermarked print image in which a digital watermark is embedded by combining the print image data formed by the print image forming unit and the copy-forgery-inhibited pattern image data formed by the copy-forgery-inhibited pattern image forming unit. An image composition unit for forming data;
A printing unit that prints a composite image, which is a watermarked print image embedded with a digital watermark, on the print medium based on the composite image data formed by the image composition unit;
A watermark pre-verification unit that verifies the presence or absence of fraud on the composite image data before the printing unit performs a printing process based on the composite image data;
The watermark pre-verification unit
When the printing device acquires from the host device that outputs a print command to the printing device, embedded data embedded in a print image as a digital watermark, and the composite image data generated based on the embedded data, Extracting embedded data from the composite image data, comparing the extracted embedded data with the embedded data acquired from the host device, and if the two do not match within a predetermined allowable range, A printing apparatus characterized by determining that an action has occurred. A data acquisition unit for acquiring print data for printing an image on a print medium from the outside;
A print image forming unit that forms print image data that is image data of a print image based on the print data acquired by the data acquisition unit;
An embedded data generation unit that generates embedded data to be embedded in a print image as a digital watermark based on the print data acquired by the data acquisition unit and device data that is unique to a printing device or a printing situation When,
Based on the embedded data generated by the embedded data generation unit, a tint block image forming unit that forms tint block image data that is image data of a tint block image of a digital watermark;
A composite image which is image data of a watermarked print image in which a digital watermark is embedded by combining the print image data formed by the print image forming unit and the copy-forgery-inhibited pattern image data formed by the copy-forgery-inhibited pattern image forming unit. An image composition unit for forming data;
A printing unit that prints a composite image, which is a watermarked print image embedded with a digital watermark, on the print medium based on the composite image data formed by the image composition unit;
A watermark pre-verification unit that verifies the presence or absence of fraud on the composite image data before the printing unit performs a printing process based on the composite image data;
The watermark pre-verification unit
The reduction formed by the printing apparatus reducing the print image data, which is the image data of the print image, from the host apparatus that outputs a print command to the printing apparatus so that the print image data is less than the amount of data that can be embedded as a digital watermark. Acquire print image data and compressed data in which a plurality of types of data are combined, including copy-forgery-inhibited pattern data obtained by encoding the copy-forgery-inhibited pattern image data based on the reduced print image data. In this case, the tint block encoded data is extracted from the compressed data, the reduced print image data is extracted from the tint block encoded data, and the luminance value of the extracted reduced print image data and the higher-level device are acquired. When the brightness value of the reduced print image data is compared and the difference between the two is larger than a predetermined threshold, the composite image Printing apparatus characterized by determining that the unauthorized action against data. A data acquisition unit for acquiring print data for printing an image on a print medium from the outside;
When the data acquisition unit acquires compressed data obtained by combining a plurality of types of data from a host device that outputs a print command to the printing device, the compressed data is decompressed, and the print data and the watermark of the electronic watermark are displayed. A compressed data decompression unit that obtains tint block encoded data obtained by encoding tint block image data that is image data of an image;
A print image forming unit that forms print image data that is image data of a print image based on the print data acquired by the compressed data decompression unit;
A copy-forgery-inhibited pattern image forming unit that forms the copy-forgery-inhibited pattern image data based on the copy-forgery-inhibited pattern encoded data acquired by the compressed data decompression unit;
A composite image which is image data of a watermarked print image in which a digital watermark is embedded by combining the print image data formed by the print image forming unit and the copy-forgery-inhibited pattern image data formed by the copy-forgery-inhibited pattern image forming unit. An image composition unit for forming data;
A printing unit that prints a composite image, which is a watermarked print image embedded with a digital watermark, on the print medium based on the composite image data formed by the image composition unit;
A watermark pre-verification unit that verifies the presence or absence of fraud on the composite image data before the printing unit performs a printing process based on the composite image data;
The watermark pre-verification unit
The reduction formed by the printing apparatus reducing the print image data, which is the image data of the print image, from the host apparatus that outputs a print command to the printing apparatus so that the print image data is less than the amount of data that can be embedded as a digital watermark. Acquire print image data and compressed data in which a plurality of types of data are combined, including copy-forgery-inhibited pattern data obtained by encoding the copy-forgery-inhibited pattern image data based on the reduced print image data. In this case, the tint block encoded data is extracted from the compressed data, the reduced print image data is extracted from the tint block encoded data, and the luminance value of the extracted reduced print image data and the higher-level device are acquired. When the brightness value of the reduced print image data is compared and the difference between the two is larger than a predetermined threshold, the composite image Printing apparatus characterized by determining that the unauthorized action against data. A data acquisition unit for acquiring print data for printing an image on a print medium from the outside;
A print image forming unit that forms print image data that is image data of a print image based on the print data acquired by the data acquisition unit;
An embedded data generation unit that generates embedded data to be embedded in a print image as a digital watermark based on the print data acquired by the data acquisition unit and device data that is unique to a printing device or a printing situation When,
Based on the embedded data generated by the embedded data generation unit, a tint block image forming unit that forms tint block image data that is image data of a tint block image of a digital watermark;
A composite image which is image data of a watermarked print image in which a digital watermark is embedded by combining the print image data formed by the print image forming unit and the copy-forgery-inhibited pattern image data formed by the copy-forgery-inhibited pattern image forming unit. An image composition unit for forming data;
A printing unit that prints a composite image, which is a watermarked print image embedded with a digital watermark, on the print medium based on the composite image data formed by the image composition unit;
A watermark pre-verification unit that verifies the presence or absence of fraud on the composite image data before the printing unit performs a printing process based on the composite image data;
The watermark pre-verification unit
When the printing apparatus acquires reduced print image data and the composite image data generated based on the copy-forgery-inhibited pattern image data based on the reduced print image data from a host apparatus that outputs a print command to the printing apparatus. Then, the reduced print image data is extracted from the composite image data, the brightness value of the extracted reduced print image data is compared with the brightness value of the reduced print image data acquired from the host device, and the difference between the two is determined in advance. A printing apparatus, wherein when it is larger than a predetermined threshold, it is determined that there has been an illegal act on the composite image data. A data acquisition unit for acquiring print data for printing an image on a print medium from the outside;
When the data acquisition unit acquires compressed data obtained by combining a plurality of types of data from a host device that outputs a print command to the printing device, the compressed data is decompressed, and the print data and the watermark of the electronic watermark are displayed. A compressed data decompression unit that obtains tint block encoded data obtained by encoding tint block image data that is image data of an image;
A print image forming unit that forms print image data that is image data of a print image based on the print data acquired by the compressed data decompression unit;
A copy-forgery-inhibited pattern image forming unit that forms the copy-forgery-inhibited pattern image data based on the copy-forgery-inhibited pattern encoded data acquired by the compressed data decompression unit;
A composite image which is image data of a watermarked print image in which a digital watermark is embedded by combining the print image data formed by the print image forming unit and the copy-forgery-inhibited pattern image data formed by the copy-forgery-inhibited pattern image forming unit. An image composition unit for forming data;
A printing unit that prints a composite image, which is a watermarked print image embedded with a digital watermark, on the print medium based on the composite image data formed by the image composition unit;
A watermark pre-verification unit that verifies the presence or absence of fraud on the composite image data before the printing unit performs a printing process based on the composite image data;
The watermark pre-verification unit
When the printing apparatus acquires reduced print image data and the composite image data generated based on the copy-forgery-inhibited pattern image data based on the reduced print image data from a host apparatus that outputs a print command to the printing apparatus. Then, the reduced print image data is extracted from the composite image data, the brightness value of the extracted reduced print image data is compared with the brightness value of the reduced print image data acquired from the host device, and the difference between the two is determined in advance. A printing apparatus, wherein when it is larger than a predetermined threshold, it is determined that there has been an illegal act on the composite image data.