JP2004015219A - Image processing apparatus, control method thereof, and image processing system - Google Patents

Abstract

An ICC profile has an open data structure, and when used via a network or the like, internal data or the like may be falsified. There was no way.
A plurality of tag data in a profile are displayed in a list, and tag data to be encrypted is selected from the list. Then, when encrypting the profile, only the selected tag data is encrypted.
[Selection diagram] FIG.

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image processing apparatus that encrypts a profile for color matching, a control method thereof, and an image processing system.
[0002]
[Prior art]
2. Description of the Related Art In recent years, color printers that can perform color matching processing using a profile (ICC profile) proposed by an ICC (International Color Consortium) have become widespread. In such a printer, by performing a color matching process in accordance with the object to be drawn, optimal color reproduction is always possible.
[0003]
Here, the color matching technology means that image data is converted into a device-independent color space (device-independent color space) and a device-specific color space by using a profile in which color conversion characteristics according to devices constituting a printing system are filed. (Device-dependent color space) to realize optimal color reproduction in the device.
[0004]
[Problems to be solved by the invention]
The ICC profile required to realize the above-described color matching may be transferred to a remote place via a network such as the Internet. However, since the data structure of the ICC profile is open to the public, when it is used via a network or the like, there is a possibility that internal data or the like may be falsified, and there is anxiety about safe use. At the present time, there has been no optimal means to make the data itself non-readable.
[0005]
SUMMARY An advantage of some aspects of the invention is to provide an image processing apparatus that appropriately encrypts an ICC profile, a control method thereof, and an image processing system.
[0006]
[Means for Solving the Problems]
As one means for achieving the above object, the image processing apparatus of the present invention has the following configuration.
[0007]
That is, an image processing apparatus that encrypts a profile for color matching, a tag selecting unit that selects tag data to be encrypted from a plurality of tag data in the profile, and a plurality of tags in the profile. Encryption means for encrypting the tag data selected by the tag selection means among the data.
[0008]
For example, the tag selecting means displays a list of a plurality of tag data in the profile and selects tag data to be encrypted from the list.
[0009]
For example, the encryption unit includes a table generation unit that generates a table storing change information for the tag data, a tag data change unit that changes the tag data based on the table, and a table that changes the table by a predetermined algorithm. And table encryption means for encrypting.
[0010]
Further, there is provided a profile restoring means for restoring the profile by decrypting the tag data in the profile encrypted by the encrypting means.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0012]
<First embodiment>
[System Configuration] FIG. 1 is a block diagram showing a schematic configuration of a printing system according to the present embodiment. As shown in FIG. 1, the system includes an image input unit 10, an image processing unit 20, and an image output unit 30, and a color conversion unit 21 in the image processing unit 20 refers to an ICC profile in a profile storage memory 22. Thus, color matching between the image input unit 10 and the image output unit 30 is performed.
[0013]
The image processing unit 20 includes a profile encryption processing unit 23 and a profile decryption processing unit 24, and performs encryption and decryption of a profile, which is a feature of the present embodiment. The ICC profile encrypted by the profile encryption unit 23 can be transmitted to a network via the communication unit 25. If the ICC profile received from the network 40 via the communication unit 25 is encrypted, the ICC profile is decrypted by the profile decryption unit 24 and then referred to by the color conversion unit 21.
[0014]
The above components in the image processing unit 20 are totally controlled by a control unit 26 including a CPU, a ROM, a RAM, and the like. Reference numeral 27 denotes a GUI unit, which performs settings related to data security (encryption and the like) in the present embodiment, which will be described later, under the control of the control unit 26.
[0015]
GUI screen FIG. 2 is a view showing an example of a display screen of the GUI 27 for setting color matching in the present system. The GUI controls ON / OFF of the color matching process. As shown in the figure, there are two setting items of the processing system in the input color space: an RGB input system and a CMYK input system. In each color space, a profile is specified, and an intent (intent) indicating a matching method is provided. ) Can be set. Further, since the profile of the output printer is related to the connected printer, it can be set appropriately in cooperation with the print mode and the like.
[0016]
In the GUI shown in the figure, when the cursor is over the “profile management” button 107, a pull-down menu is displayed, and any one of “RGB input”, “CMYK input”, and “printer setting” can be selected. Then, when any of these items is selected, a “profile management” sheet shown at the bottom of the figure is displayed.
[0017]
The ICC profile in the present embodiment is configured to be appropriately selected from the profile storage memory 22 and registered, and available ICC profiles are displayed as a list 201 on a “profile management” sheet. When a new profile is to be added, the “registration” button 202 on the “profile management” sheet is pressed after saving the ICC profile in the profile storage memory 22. Then, when the new ICC profile becomes available, the information is displayed in the list 201. To delete a registered profile, the user may select an ICC profile displayed in the list 201 and then press a “delete” button 203.
[0018]
In the present embodiment, when setting the security of the ICC profile, the user selects the target ICC profile from the list 201 on the “profile management” sheet, and then presses the “security setting” button 204. As a result, a “security setting” sheet shown in FIG. 3 is displayed, and the file itself can be encrypted and decrypted. The details of the profile encryption and decryption processes in this embodiment will be described later.
[0019]
Here, a profile generally has a plurality of conversion data therein as tags. For example, LUT data (called an A2B tag) for converting a certain device color space to a device-independent color space, and conversely, LUT data (called a B2A tag) for converting a device-independent color space to a device color space. ). Further, they are classified according to the type of LUT data to be color-converted (for example, into B2A0, B2A1, B2A2, etc.).
[0020]
This embodiment is characterized in that encryption target data in a profile can be set for each tag. Specifically, in the “security setting” sheet shown in FIG. 3, all tag information of the currently selected profile 301 is displayed as a list 307 on the screen. After selecting a tag to be encrypted from the list 307 with the tag selection radio button 303 and pressing the encryption button 304, the data of the selected tag portion can be encrypted. FIG. 3 shows a state where a “gamt” (Gamut: gamut) tag is selected. Hereinafter, an example in which gamut tag data in a profile is encrypted will be described.
[0021]
Encrypted Scan Table In this embodiment, an encrypted scan table is used when encrypting and decrypting an ICC profile. FIG. 4 shows the configuration of the encrypted scan table. As shown in the figure, the encrypted scanning table is composed of a plurality of field data, and each field has an ID indicating a data processing order, an offset address indicating a position of data to be processed, and a data to be processed. , A processing pattern ID indicating information for bit operation with respect to.
[0022]
Here, as the processing pattern ID, a rule is prepared in advance such that if this is "1", only the upper 4 bits are XORed, and if it is "2", the third and sixth bits are switched. deep. Since this rule is similarly referred to for bit restoration, the contents of the bit operation should be designed so that the original data can be restored only in accordance with the processing pattern ID.
[0023]
In the present embodiment, one encrypted scan table is generated by randomly generating the offset address and the processing pattern ID within a predetermined range.
[0024]
When encrypting a profile in the present embodiment, the encrypted scan table is encrypted (or decrypted) by a predetermined algorithm. At this time, a change is made in that bit data based on the set processing pattern ID is performed on the substantial data of the profile (in this case, gamut tag data). When the gamut tag data is decrypted, the original data can be reproduced by performing the inverse operation of the bit operation with reference to the encrypted scan table.
[0025]
[Encryption Processing] The encryption processing of the ICC profile in the present embodiment will be described below with reference to the flowchart shown in FIG.
[0026]
First, in step S111, a profile to be encrypted is read. Subsequently, in step S112, the profile is searched for an encryption flag indicating whether a bit operation (encryption bit processing) using the encryption scan table has been performed. Note that the flag information in the profile is used as the encryption flag. Then, the result of the determination is received in step S113, and it is determined whether or not encrypted bit processing can be performed on the read profile. In this embodiment, that is, if the flag information indicates that the encryption bit processing has been completed, it is determined that encryption is not possible. This makes it possible to avoid performing the encryption bit processing again for the profile for which the encryption bit processing has already been performed.
[0027]
If the encryption bit processing is possible, the process advances to step S114 to generate an encryption scan table. Then, in step S115, the offset address and the processing pattern ID are extracted in the order of the stored ID numbers with reference to each field data of the generated encrypted scanning table, and the gamut tag data constituting the profile is extracted. Bit operation processing according to the processing pattern ID is appropriately performed.
[0028]
Then, after performing a general initialization process required for encryption in step S116, encryption of the encrypted scan table is performed in step S117. Here, the encryption method is not particularly limited, and any known encryption method can be applied.
[0029]
After reconfiguring the tag data of the profile in step S118, flag data indicating that the profile encryption bit processing has been performed is embedded in the tag data in step S119. Then, in step S120, the ICC profile is reconstructed using the tag data.
[0030]
In step S121, it is checked whether or not the read ICC profile itself can be overwritten. Only when the file itself can be overwritten, the profile is updated in step S122.
[0031]
As described above, in the present embodiment, the profile encryption bit process, that is, the bit operation process on the gamut tag data and the scan table encryption process are performed according to the flowchart shown in FIG.
[0032]
In this embodiment, if it is determined at the start of printing that the set ICC profile has been encrypted, the decryption process is performed inside the system. Hereinafter, the decoding process in the present embodiment will be described with reference to the flowchart in FIG.
[0033]
First, in step S211, the ICC profile set for printing is read, and the encryption flag is searched in step S212. Then, in step S213, based on the encryption flag, it is determined whether or not the profile needs to be decrypted. That is, if the encryption flag indicates that the encryption has been completed, it is determined that it is necessary to perform the encryption scan table decryption process and the profile bit process (decryption bit process).
[0034]
If it is determined that decryption is necessary, the encryption scan table is cut out in step S214, general initialization necessary for decryption addition is performed in step S215, and encryption is performed in step S216. The decoding process of the modified scan table is performed.
[0035]
In step S217, the offset address and the processing pattern ID are extracted in the order of the stored ID numbers with reference to each field data of the decoded scan table, and the processing pattern ID is indicated for the gamut tag data of the profile. The inverse operation of the bit operation is appropriately performed.
[0036]
Next, in step S218, the tag data of the profile is reconstructed. In step S219, the profile is reconstructed using the tag data. In step S220, the decoded ICC profile is set in the present system.
[0037]
Note that the ICC profile decrypted in the present embodiment is expanded only in the internal resources (work memory or the like) where the present system operates so as not to be referred to from the outside.
[0038]
As described above, according to the present embodiment, the LUT tag portion of the ICC profile is encoded. Thereby, the ICC profile can be provided with non-readability without falsification of its internal data, so that it can be safely used via a network.
[0039]
Further, since it is possible to selectively encrypt arbitrary data among the internal data of the ICC profile, it is possible to optimize the encryption system.
[0040]
In the present embodiment, an example has been described in which a bit operation is performed on a gamut tag in a profile. However, needless to say, the present invention can be applied to a case where arbitrary plural pieces of tag data are selected.
[0041]
<Other embodiments>
The present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), but may be a device including one device (for example, a copying machine, a facsimile machine, etc.). May be applied.
Further, an object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and a computer (or CPU or MPU) of the system or apparatus to store the storage medium. Needless to say, this can also be achieved by reading out and executing the program code stored in the.
[0042]
In this case, the program code itself read from the storage medium realizes the function of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.
[0043]
As a storage medium for supplying the program code, for example, a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, or the like is used. I can do it.
[0044]
When the computer executes the readout program code, not only the functions of the above-described embodiments are realized, but also an OS (Operating System) running on the computer based on the instruction of the program code. It goes without saying that a case where a part of the actual processing is performed and the function of the above-described embodiment is realized by the processing is also included.
[0045]
Further, after the program code read from the storage medium is written into a memory provided on a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that a CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.
[0046]
【The invention's effect】
As described above, according to the present invention, it is possible to appropriately encrypt an ICC profile by encoding an arbitrary tag portion in the ICC profile.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a schematic configuration of a printing system according to an embodiment.
FIG. 2 is a diagram illustrating an example of a GUI screen for performing color matching setting in the embodiment.
FIG. 3 is a diagram illustrating an example of a GUI screen for performing security setting of a profile according to the embodiment.
FIG. 4 is a diagram illustrating a configuration example of an encryption scan table according to the embodiment;
FIG. 5 is a flowchart illustrating an encryption process according to the embodiment.
FIG. 6 is a flowchart illustrating a decoding process according to the embodiment.
[Explanation of symbols]
Reference Signs List 10 Image input unit 20 Image processing unit 21 Color conversion unit 22 Profile storage memory 23 Profile encryption unit 24 Profile decryption unit 25 Communication unit 26 Control unit 27 GUI unit 30 Image output unit 40 Network

Claims (19)

An image processing apparatus for encrypting a profile for color matching,
Tag selection means for selecting tag data to be encrypted from a plurality of tag data in the profile,
Encrypting means for encrypting tag data selected by the tag selecting means, among a plurality of tag data in the profile,
An image processing apparatus comprising: 2. The image processing apparatus according to claim 1, wherein the tag selection unit displays a list of a plurality of tag data in the profile and selects tag data to be encrypted from the list. Further, storage means for storing a plurality of profiles,
A profile selection unit for selecting a profile to be encrypted from the storage unit;
The image processing apparatus according to claim 1, further comprising: The encryption means,
Table generating means for generating a table storing change information for the tag data,
Tag data changing means for changing the tag data based on the table,
2. The image processing apparatus according to claim 1, further comprising table encryption means for encrypting the table using a predetermined algorithm. The table generation means stores bit operation information for the tag data in the table,
The image processing apparatus according to claim 4, wherein the tag data changing unit performs a bit operation on the tag data based on the bit operation information. 6. The image processing apparatus according to claim 5, wherein the table generation unit stores information indicating a processing order, information indicating a data position, and the bit operation information of the tag data in the table. . 7. The image processing apparatus according to claim 6, wherein the table generation unit generates the information indicating the data position and the bit operation information as random values within a predetermined range. The image processing apparatus according to claim 4, wherein the tag data changing unit embeds information indicating that the tag data has been changed in the tag data changed based on the table. 2. The image processing apparatus according to claim 1, further comprising a profile updating unit that updates the profile stored in the storage unit by replacing the profile with a profile in which tag data is encrypted by the encryption unit. . 5. The image processing apparatus according to claim 4, further comprising transmitting means for transmitting the tag data changed by said tag data changing means and the table encrypted by said encrypting means to an external device. 2. The image processing apparatus according to claim 1, further comprising a profile restoring unit that restores the profile by decoding tag data in the profile encrypted by the encrypting unit. Further, color matching means for performing color matching using the profile restored by the restoration means,
Image output means for outputting image data after color matching by the color matching means,
The image processing apparatus according to claim 11, comprising: Further, table decryption means for decrypting the table encrypted by the table encryption means,
Tag data restoring means for restoring the tag data changed by the tag data changing means to a value before the change by the tag data changing means based on the table;
The image processing apparatus according to claim 4, further comprising: The tag data restoring unit performs a reverse operation of the bit operation performed by the tag data changing unit on the tag data changed by the tag data changing unit based on the bit operation information stored in the table. 14. The image processing apparatus according to claim 13, wherein a value before the change is restored. 14. The image processing apparatus according to claim 13, wherein the table decoding unit and the tag data restoring unit operate when information indicating that the tag data has been changed exists in the tag data. An image processing system in which a plurality of image processing apparatuses are connected via a network,
A first image processing apparatus that encrypts a profile for color matching,
Tag selection means for selecting tag data to be encrypted from a plurality of tag data in the profile,
Encrypting means for encrypting tag data selected by the tag selecting means, among a plurality of tag data in the profile,
Transmitting means for transmitting a profile in which the tag data is encrypted by the encrypting means to the second image processing apparatus via the network,
The second image processing device includes:
Receiving means for receiving the profile transmitted from the transmitting means,
Restoring means for restoring the profile by decoding the encrypted tag data in the profile,
An image processing system comprising: A method for controlling an image processing device that encrypts a profile for color matching,
From a plurality of tag data in the profile, a tag selecting step of selecting tag data to be encrypted,
Among a plurality of tag data in the profile, an encryption step of encrypting the tag data selected in the tag selection step,
A method for controlling an image processing apparatus, comprising: A program which, when executed on a computer, causes the computer to operate as the image processing apparatus according to claim 1. A recording medium recording the program according to claim 18.

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