JP2001309149A - Image processing unit, image processing system, and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing unit that detects falsification having been applied to an image. SOLUTION: The image processing unit of this invention is provided with an image input section 10, a correction detection section 20 that detects whether or not image data have been corrected by referencing a correction detection code, a correction distribution generating section 30 that generates distribution information of corrected parts of the image data, a correction permissibility discrimination section 40 that discriminates whether or not contents of the correction denoted in the distribution information are within a permissible range on the basis of prescribed permission conditions, and an image output restriction section 50 that restricts an output of the image data when the discrimination 40 discriminates that the contents of the correction applied to the image data are at the outside of the permissible range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus, and more particularly, to an image processing apparatus for detecting falsification of an image.

[0002]

2. Description of the Related Art Conventionally, when taking a construction photograph to be submitted to a construction orderer in civil engineering work or the like, a construction blackboard on which the details of the construction and the progress are written has been photographed against the background of the construction site. In recent years, a construction photograph is taken with a digital camera, and a construction photograph album is sometimes submitted in the form of a digital photograph album. In the case of digital images, it is relatively easy to process the images using a computer or the like. For example, correction of contrast, white balance, and the like can be easily processed. A construction photo album in which the contrast, white balance, and the like are appropriately corrected is useful for both the submitting side and the receiving side because the photograph is easy to see.

[0003]

However, since the digital image is easy to process, the contents of the construction photograph may be falsified for an improper purpose. On the other hand, simply detecting the modification applied to the image and restricting it all also restricts the modification applied for a legitimate purpose, which is not appropriate.

Therefore, an object of the present invention is to provide an image processing apparatus capable of solving the above-mentioned problems.
This object is achieved by a combination of features described in the independent claims. The dependent claims define further advantageous embodiments of the present invention.

[0005]

According to a first aspect of the present invention, there is provided an image input unit for inputting the image data including a predetermined modified detection code.
A modification detection unit that detects whether or not modification has been applied to the image data with reference to the modification detection code; and creates distribution information of modification locations in the image data based on a detection result by the modification detection unit. A modification distribution creating unit, a modification allowance determination unit that determines whether the content of the modification indicated in the distribution information is within an allowable range based on a predetermined allowable condition, and the content of the modification added to the image data And an image output restricting unit that restricts the output of the image data when it is determined that is outside the allowable range.

[0006] The modification allowance judging section may judge that the content of the modification is within an allowable range when the modification region indicated in the distribution information occupies an area equal to or more than a predetermined ratio in the image data. . The modification allowance determination unit may determine that the content of the modification is outside the allowable range when the modification location indicated in the distribution information is unevenly distributed in the image data to a predetermined degree or more. The image output restricting unit may restrict the recording of the image data, which has been modified outside the allowable range, on a recording medium. The image output restricting unit may restrict printing of the image data to which modification outside the allowable range has been added. The image input unit may further include an image reading unit that optically scans an image to generate the image data and a modification detection code adding unit that adds a modification detection code to the image data.

According to a second aspect of the present invention, there is provided a photographing apparatus having a photographing unit for photographing a subject to generate image data, and a modification detection code adding unit for adding a predetermined modification detection code to the image data. A modification detection unit that detects whether or not the image data has been modified with reference to the modification detection code included in the image data; and A modification distribution creating unit that creates distribution information of the modification locations in the modification, a modification permission determination unit that determines whether the content of the modification indicated in the distribution information is within an allowable range based on a predetermined allowable condition, and the image An image processing device having an image output regulating unit that regulates the output of the image data when it is determined that the content of the modification added to the data is out of an allowable range. To provide a beam.

According to a third aspect of the present invention, there is provided an image capturing apparatus having an image capturing section for capturing an image of a subject to generate image data, an image processing apparatus having an encryption processing section for encrypting the image data, and An image input unit that inputs the image data, a decoding processing unit that decodes the image data, a modification detection code addition unit that adds a modification detection code to the decoded image data, and the modification detection code addition unit that is included in the image data. A modification detection unit that detects whether or not the image data has been modified with reference to a modification detection code; and a modification that creates distribution information of modified portions in the image data based on a detection result by the modification detection unit. A distribution creation unit, a modification allowance determination unit that determines whether or not the content of the modification indicated in the distribution information is within an allowable range based on a predetermined allowable condition; If the content of the retouching is judged to be out of tolerance, to provide a system and an image processing apparatus and an image output regulating section for regulating the output of the image data.

According to a fourth aspect of the present invention, there is provided a recording medium storing a program for causing a computer to process image data, wherein the program stores a predetermined modification detection code included in the image data. A modification detection module that refers to the image data to detect whether modification has been added, and a modification distribution creation module that creates distribution information of modification locations in the image data based on a detection result by the modification detection unit. A modification allowance determination module that determines whether the content of the modification indicated in the distribution information is within an allowable range based on a predetermined allowable condition, and the content of the modification added to the image data is out of the allowable range. If it is determined that there is, the image data can be read by a computer including an image output regulation module that regulates the output of the image data. To provide a recording medium.

The above summary of the invention does not enumerate all of the necessary features of the present invention, and a sub-combination of these features can also be an invention.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described through embodiments of the present invention. However, the following embodiments do not limit the invention according to the claims and are described in the embodiments. Not all combinations of features are essential to the solution of the invention.

An embodiment in which the present invention is applied to image processing of a construction photograph will be described below. The image processing apparatus of the present invention includes an electronic computer such as a personal computer and an apparatus such as a lab system. These devices detect tampering of an image by using a modification detection code. here,
The modification detection code is a redundant code added to the image data in advance to detect the modification added to the image data. The modification detection code is obtained by a predetermined calculation using the image data to be added. The modification detection code is
The calculation may be performed in units of bits or bytes, or may be performed in units of several byte blocks. When some kind of data modification is applied to the image data to which the modification detection code is added, a value obtained by a predetermined operation partially or entirely does not match the modification detection code. By utilizing this, it is possible to detect whether or not the image data has been modified.

(First Embodiment) FIG. 1 is a functional block diagram of an album creating apparatus for editing a photo image to create an electronic album. This album creating device is an example of the image processing device of the present invention. Here, the electronic album is
A plurality of photographs are edited in a format that can be viewed on a computer screen, and are recorded on a recording medium such as a CD-ROM. The album creating apparatus according to the present embodiment regulates printing and recording operations of intentionally falsified image data.

The album creating apparatus 100 includes an image input unit 1
0, a modification detection unit 20, a modification distribution creation unit 30, a modification permission determination unit 40, an image output regulation unit 50, an image recording unit 60, and an image printing unit 70.

The image input unit 10 includes an album creating device 10
Input image data to 0. A modification detection code is added in advance to the image data input by the image input unit 10. This image data may be data to which a modification detection code has been added by, for example, a photographing device. For example, check bits, check digits,
Check character, checksum, CRC (Cyclic R
An error detection code such as an edundancy check (cyclic redundancy check) code may be used.

When inputting a digital image photographed by a digital camera to the album creating apparatus 100, the image input unit 10 uses various reading devices corresponding to a recording medium storing the input digital image. For example, a reading device or the like for reading image data from a removable recording medium such as a nonvolatile semiconductor memory card is used as the image input unit 10. As a memory card, for example, EE
PROM (Electrically Erasable Programmable Read-
There is a medium that can electrically read and write data, such as Only Memory. When reading image data from a floppy (registered trademark) disk, MO, CD-ROM, or the like, a floppy drive, MO drive, CD drive, or the like is used as the image input unit 10, respectively.

The modification detection unit 20 detects whether or not the image data has been modified by referring to a predetermined modification detection code included in the image data. The modification detection unit 20 detects whether or not the image data has been modified by comparing a value obtained by a predetermined operation from the image data with a modification detection code. By adding the modification detection code to the image data at a predetermined cycle, it is possible to detect the presence or absence of the modification at the cycle in the image data.

The modification distribution creating section 30 creates distribution information of the modification places in the image data based on the detection result by the modification detecting section 20. The modification distribution creating unit 30 creates a modification distribution in the image data based on, for example, a detection result indicating whether or not the image data has modification in a predetermined cycle.

The modification allowance judging section 40 judges whether or not the contents of the modification indicated in the distribution information are within an allowable range based on a predetermined allowable condition. For example, correction of the contrast and white balance of an image is not a correction for an improper purpose, and is thus regarded as a correction that should be allowed. In the case of these corrections, since the entire image is usually modified, the detected correction portion is also distributed over the entire image data. Therefore, the predetermined allowable condition in the present embodiment is set so that the modification is permitted when the modification location is almost entirely distributed in the image data. For example, the allowable condition may be determined by the area of the correction region. That is, the ratio of the area of the retouched area allowed in the image data may be determined by the allowable condition. The modification allowance determination unit 40 determines that the content of the modification is within the allowable range when the modification region indicated in the distribution information occupies an area equal to or more than the ratio defined in the allowable condition in the image data.

For example, if the contents of an image are falsified for an unjust purpose, traces of the modification often remain only in a part of the image data, not in the entire image data. In this case, the modified portions detected by the modification detection unit 20 are partially distributed in the image data. If the area occupied by the modified area indicated by the distribution information in the image data is smaller than the ratio defined in the allowable condition, the modification allowable determination unit 40 determines that the content of the modification is outside the allowable range.

The editing processing unit 42 edits a plurality of input image data into an electronic album format. Editing unit 4
2 may arrange a plurality of image data over a plurality of pages, for example. For example, desired character strings may be displayed side by side for each image according to an instruction from the user.
The album editing process by the editing processing unit 42 may proceed in an interactive manner with the user.

The image recording section 60 records the electronic album edited by the editing processing section 42 on a recording medium. Examples of the recording medium include a magnetic recording medium such as a hard disk and a floppy disk, an optical recording medium such as a CD-ROM,
It may be a magneto-optical recording medium such as an MO. Image recording unit 6
For 0, various writing devices corresponding to the recording medium, for example, a floppy drive, a CD-R drive, an MO drive, and the like are used.

The image printing unit 70 prints the electronic album edited by the editing processing unit 42. Image printing unit 70
May be, for example, an ink jet printer or a laser printer. By combining the pages printed by the image printing unit 70, a construction photo album is formed.

The image output restricting section 50 restricts the output of the image data when it is determined that the content of the modification added to the image data is outside the allowable range. For example, the image output restriction unit 50 may restrict the image recording unit 60 from recording an electronic album including image data outside the allowable range on a recording medium. For example, the image output restriction unit 50 restricts printing of an electronic album including image data outside the allowable range by the image printing unit 70.

As described above, when it is determined that the modification applied to the image data is out of the allowable range, the image output restricting section 50 restricts the output of the image data. Therefore, it is not possible to record or print on a recording medium an electronic album including image data to which tampering has been added,
Malicious electronic albums cannot be submitted to the contractor. It can be expected that the image data is prevented from being tampered with for an unjust purpose.

(Second Embodiment) This embodiment has substantially the same configuration as the first embodiment except that the permissible conditions for the contents of the modification added to the image data are different. For example, correction of the contrast and white balance of an image is not a correction for an improper purpose, and is thus regarded as a correction that should be allowed. In the case of these corrections, the correction is usually made almost uniformly over the entire image, so that the detected correction portion is hardly unevenly distributed. Therefore, the permissive condition in the present embodiment is set so that, when the retouched portion is unevenly distributed in the image data by a predetermined degree or more, the content of the retouch is determined to be out of the permissible range. In the case of a method for detecting a modified portion using a modified detection code, even a modified portion may not be actually detected with a certain probability, so the degree of uneven distribution is determined by taking into account that fact. You may. The modification permission determination unit 40 determines that the content of the modification is out of the allowable range when the modification location indicated in the distribution information is unevenly distributed in the image data to a predetermined degree or more.

Thus, even if, for example, an illegal alteration to be added to a part of the image data is performed at a plurality of locations, the modified locations are not uniform and can be detected depending on the degree of uneven distribution.

(Third Embodiment) FIG. 2 shows details of an image input unit 10 in a third embodiment. The album creating apparatus according to the present embodiment reads an image from a photo film or a printed photo to create an electronic album. The configuration and functions other than the image input unit 10 are substantially the same as those of the first and second embodiments.

The image input section 10 has an image reading section 12 and a modification detection code adding section 14. The image reading unit 12 generates image data by optically scanning an image. When reading an image from a photographic film such as a negative film or a positive film, the image reading unit 12 uses, for example, a film scanner that optically scans an image on the photographic film and generates electrical information such as digital image data. Is also good.
When reading an image from a print photograph, the image reading unit 12
For example, a photo scanner that optically scans an image on photographic paper to generate electrical information such as digital image data may be used.

The modification detection code adding section 14 is a part of the image reading section 1.
2 adds a predetermined correction detection code to the image data generated. As the modification detection code, a predetermined code that allows the modification detection unit 20 to detect a modification location later is used.

As described above, in this embodiment, the modification detection code is added even when an image is read from a photo film or a printed photograph. Therefore, when the modification is added for the purpose of illegally altering the contents of the photograph after the modification detection code is added, this can be detected.

(Fourth Embodiment) FIG. 3 is a functional block diagram showing an album creating system according to a fourth embodiment. The album creation system in the present embodiment is an example of the image processing system of the present invention. This system is
It includes a photographing device 200 and an album creating device 100.
The album creating apparatus 100 has substantially the same configuration and functions as the album creating apparatus 100 in the first and second embodiments.

The photographing apparatus 200 has a photographing section 210 and a modification detection code adding section 220. The imaging unit 210 generates an image data by imaging an object. The modification detection code adding unit 220 adds a predetermined modification detection code to the image data. As the modification detection code, a predetermined code that allows the modification detection unit 20 to detect a modification location later is used. The photographing device 200 may be, for example, a digital still camera.

As described above, in the present embodiment, the photographing device 20 that has photographed the image data used for the electronic album
0 adds the modification detection code. Therefore, even if a modification is made for the purpose of improperly altering the contents of a photograph after photographing and before input to the photographing device 200, this can be detected.

(Fifth Embodiment) FIG. 4 is a functional block diagram showing an album creating system according to a fifth embodiment. The album creation system in the present embodiment is an example of the image processing system of the present invention. This system is
It includes a photographing device 200 and an album creating device 100.

The photographing apparatus 200 has a photographing section 210 and an encryption processing section 230. The imaging unit 210 generates an image data by imaging an object. The encryption processing unit 230
The image data is encrypted by a predetermined method that can be decrypted on the album creating apparatus 100 side. As the encryption method, for example, a format in which image data cannot be referenced until decryption may be used. Further, the encryption processing unit 230 may scramble the image data so that the image data cannot be referred to until the image data is decrypted.

The album creating apparatus 100 includes an image input unit 1
0, a decoding unit 16 and a modification detection code adding unit 14. Further, the album creating apparatus 100 includes a modification detecting section 20, a modification distribution creating section 30, a modification permission determining section 40, an editing processing section 42, an image output regulating section 50, an image recording section 60, and an image printing section 70.
And further comprising:

The image input unit 10 inputs the encrypted image data. The decoding unit 16 decodes the image data.
The modification detection code adding unit 14 adds a modification detection code to the decoded image data. The configuration and functions of the modification detection unit 20 and subsequent units are substantially the same as those of the first and second embodiments.

As described above, the image data used for the electronic album in this embodiment is encrypted and cannot be referred to from the photographing by the photographing device 200 to the decryption by the album creating device 100. Therefore, until the modification detection code is added by the album creating apparatus 100, it can be prevented from being modified for the purpose of illegally altering the contents of the photograph.

Next, a configuration in the case where the album creating apparatus in the first to fourth embodiments is realized using an electronic computer such as a personal computer or a workstation will be described. FIG. 5 is a hardware configuration diagram of the album creating apparatus 100. The album creating apparatus 100 includes an image input unit 300, an operation unit 320, a CPU 310, an R
OM 330, RAM 350, hard disk 340, C
A D drive 360 and a printer 380 are provided. Each component performs data exchange and cooperation through a bus 390.

The image data is input by the image input unit 300. The image input unit 300 is shown in FIGS.
Corresponds to the image input unit 10. Various devices can be used as the image input unit 300 according to the medium on which the image data is recorded. For example, a memory card drive, floppy drive, CD drive, MO drive, MD drive, photo scanner, film scanner, or the like may be used as the image input unit 300. Each device may be integrated with a computer that is a main component of the album creating device 100, or may be a separate unit separate from the computer.

The operation unit 320 receives a necessary operation by the user. For example, a keyboard or a mouse may be used as the operation unit.

CPU 310 has ROM 330 and RAM
It operates based on the program stored in 350. The hard disk 340 stores the image data and the CPU 31
Stores data such as a program for operating 0. CD
The drive 360 reads data or a program from the CD disk 370 and provides it to at least one of the RAM 350, the hard disk 340, and the CPU 310. The CD drive 360 may be a CD-R drive capable of recording data on CD-R media.
In this case, it functions as the image recording unit 60 in FIGS.

The printer 380 functions as the image printing section 70 shown in FIGS. Printer 380 may be, for example, an ink jet printer or a laser printer. The printer 380 may be integrated with a computer as a main component of the album creating apparatus 100, or may be a separate unit separated from the computer.

FIG. 6 is a block diagram showing a functional configuration of software executed by the CPU 310. These software are stored in a recording medium such as a CD disk 370 and provided to the user. The software stored on the recording medium may be compressed or uncompressed. The software is installed on the hard disk 340 from the recording medium, read out to the RAM 350, and
Is executed by

The software stored on the recording medium and provided, that is, the software installed on the hard disk 340, has a functional configuration of the image input module 4
00, a modification detection module 410, a modification distribution creation module 420, a modification permission determination module 430, an edit processing module 440, an image output regulation module 450, an image recording module 460, and an image printing module 470. Each program module has each function in FIGS.

CD disk 37 as an example of a recording medium
0 may store some or all of the functions of the operation of the album creating apparatus 100 described in the present application. The CD disk 370 can store some or all of the functions of other devices. These programs may be read directly from the recording medium to the RAM 350 and executed.

As a recording medium, in addition to the CD disk 370, an optical recording medium such as a DVD or a PD, a magnetic recording medium such as a floppy disk or an MD, a magneto-optical recording medium such as an MO, a tape-shaped recording medium, a non-volatile Semiconductor memory card or the like can be used. The recording medium storing the above program is used only for manufacturing an image processing apparatus, and the manufacture and sale of such a recording medium as a business constitutes infringement of the patent right based on the present application. It is clear that.

As described above, according to the first to fifth embodiments, the modification detection code is added to the image data at a predetermined period, so that the presence or absence of the modification can be detected at the period in the image data. it can.

When the area occupied by the modified area indicated in the distribution information in the image data is smaller than the ratio defined in the allowable condition, it is determined that the content of the modification is out of the allowable range, and the tampering is incorrectly performed. Can be detected.

When it is determined that the modification applied to the image data is out of the allowable range, the image output restriction unit 50 restricts the output of the image data. Therefore, it is impossible to record or print an electronic album including image data to which an illegal tampering has been added on a recording medium, and it is impossible to submit a malicious electronic album to a contractor of a construction. It can be expected that the image data is prevented from being tampered with for an unjust purpose.

Further, in the second embodiment, when the modified portion indicated in the distribution information is unevenly distributed in the image data to a predetermined degree or more, it is determined that the content of the modified is out of the allowable range, thereby making the illegal operation. Tampering can be detected.

Further, even when a part of the image data is unfairly tampered with at a plurality of places, the modified places are not uniform, so that it can be detected depending on the degree of uneven distribution.

In the third embodiment, the modification detection code is added even when an image is read from a photo film or a printed photograph. Therefore, even if the modification is added for the purpose of illegally altering the contents of the photograph after the modification detection code is added, this can be detected.

In the fourth embodiment, the photographing apparatus 200 that has photographed the image data used for the electronic album adds the modification detection code. Therefore, even if a modification is made for the purpose of improperly altering the contents of a photograph after photographing and before input to the photographing device 200, this can be detected.

The image data used for the electronic album in the fifth embodiment is encrypted and cannot be referred to from the photographing by the photographing device 200 to the decryption by the album creating device 100. Therefore, until the modification detection code is added by the album creating apparatus 100, modification for the purpose of illegally falsifying the contents of the photograph can be prevented.

Although the present invention has been described with reference to the embodiment, the technical scope of the present invention is not limited to the scope described in the above embodiment. It is understood by those skilled in the art that various changes or improvements can be added to the above embodiment. It will be understood by those skilled in the art from the description of the claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

[0058]

As is apparent from the above description, according to the present invention, tampering added to an image can be detected.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of an album creating apparatus that edits a photo image to create an electronic album.

FIG. 2 is a diagram illustrating details of an image input unit 10 according to a third embodiment.

FIG. 3 is a functional block diagram illustrating an album creating system according to a fourth embodiment.

FIG. 4 is a functional block diagram illustrating an album creating system according to a fifth embodiment.

FIG. 5 is a hardware configuration diagram of the album creating apparatus 100.

FIG. 6 is a block diagram illustrating a functional configuration of software executed by a CPU 310.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 image input unit 12 image reading unit 14 modification detection code adding unit 16 decoding unit 20 modification detection unit 30 modification distribution creation unit 40 modification permission determination unit 42 editing processing unit 50 image output regulation unit 60 image recording unit 70 image printing unit 100 album Creation device 200 Imaging device 210 Imaging unit 220 Modification detection code adding unit 230 Encryption processing unit

Continuation of the front page F term (reference) 5B057 AA11 CE08 CG01 CG09 DA08 DA15 DB02 DC04 DC19 DC36 5C076 AA14 BA06 5C077 LL14 PP19 PP23 PP65 PP66 TT09 5J104 AA08 LA01 9A001 EE04 HZ23 KK53

Claims (9)

[Claims] 1. An image processing apparatus for processing image data, comprising: an image input unit for inputting the image data including a predetermined correction detection code; and correcting the image data by referring to the correction detection code. A modification detection unit that detects whether or not a modification has been added; a modification distribution creation unit that creates distribution information of modification locations in the image data based on a detection result by the modification detection unit; A modification allowance determination unit that determines whether the content of the modification is within an allowable range based on a predetermined allowable condition, and when it is determined that the content of the modification added to the image data is outside the allowable range, An image processing apparatus comprising: an image output restriction unit that restricts output of the image data. 2. The modification allowance determination unit determines that the content of the modification is within an allowable range when the modification region indicated in the distribution information occupies an area equal to or more than a predetermined ratio in the image data. The image processing apparatus according to claim 1, wherein: 3. The modification allowance determination unit determines that the content of the modification is out of an allowable range when the modification location indicated in the distribution information is unevenly distributed in the image data by a predetermined degree or more. The image processing apparatus according to claim 1, wherein: 4. The image according to claim 1, wherein the image output restricting unit restricts recording of the image data, which has been modified outside an allowable range, on a recording medium. Processing equipment. 5. The image processing apparatus according to claim 1, wherein the image output restricting unit restricts printing of the image data that has been modified outside an allowable range. 6. An image input unit having an image reading unit that optically scans an image to generate the image data and a modification detection code adding unit that adds a modification detection code to the image data. The image processing apparatus according to claim 1, wherein: 7. A photographing apparatus comprising: a photographing section for photographing a subject to generate image data; and a modification detection code adding section for adding a predetermined modification detection code to the image data; A modification detection unit that detects whether or not modification has been applied to the image data with reference to the modification detection code; and creates distribution information of modification locations in the image data based on a detection result by the modification detection unit. A modification distribution creating unit, a modification allowance determination unit that determines whether the content of the modification indicated in the distribution information is within an allowable range based on a predetermined allowable condition, and the content of the modification added to the image data And an image processing device having an image output restricting unit for restricting the output of the image data when it is determined that the image data is outside the allowable range. . 8. An image capturing apparatus having an image capturing section for capturing an object to generate image data, an encryption processing section for encrypting the image data, and an image input section for inputting the encrypted image data When,
A decoding processing unit that decodes the image data, a modification detection code adding unit that adds a modification detection code to the decoded image data, and the image data with reference to the modification detection code included in the image data. A modification detection unit that detects whether or not modification has been applied; a modification distribution creating unit that creates distribution information of modification locations in the image data based on a detection result by the modification detection unit; A modification allowance determination unit that determines whether the content of the modification is within an allowable range based on a predetermined allowable condition, and when it is determined that the content of the modification added to the image data is outside the allowable range. An image processing apparatus having an image output restricting unit for restricting the output of the image data. 9. A recording medium storing a program for causing a computer to process image data, wherein the program corrects the image data with reference to a predetermined correction detection code included in the image data. A modification detection module that detects whether or not the modification has been added; a modification distribution creating module that creates distribution information of modified portions in the image data based on a detection result of the modification detection unit; and the modification that is indicated in the distribution information. A modification allowance determination module that determines whether or not the content of the modification is within an allowable range based on a predetermined allowable condition, and when the content of the modification added to the image data is determined to be out of the allowable range, A computer-readable recording medium, comprising: an image output regulating module that regulates output of image data. .