JP3799298B2 - Image processing apparatus, control method therefor, and image processing system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image processing apparatus that encrypts a color matching profile, a control method thereof, and an image processing system.
[0002]
[Prior art]
In recent years, color printers that enable color matching processing using a profile (ICC profile) proposed by the ICC (International Color Consortium) have become widespread. In such a printer, optimal color reproduction is always possible by performing color matching processing according to the object to be drawn.
[0003]
Here, the color matching technology refers to a device-independent color space (device-independent color space) and a device-specific color space using a profile in which color conversion characteristics according to the devices constituting the printing system are filed. By performing mutual conversion with (device-dependent color space), optimal color reproduction in the device is realized.
[0004]
[Problems to be solved by the invention]
The ICC profile necessary for realizing the color matching as described above 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, there is a possibility that internal data may be falsified when used via a network or the like. In addition, there has been no optimum means to make the data itself unreadable.
[0005]
The present invention has been made in view of the above problems, and an object thereof is to provide an image processing apparatus, a control method thereof, and an image processing system that appropriately encrypt an ICC profile.
[0006]
[Means for Solving the Problems]
As a means for achieving the above object, an image processing apparatus of the present invention comprises the following arrangement.
[0007]
That is, an image processing apparatus for changing a profile for color matching, in the case of subtraction processing for the data in the profile, the table generating means for generating a table that stores information about subtraction amount, on said table Based on the data in the profile, the profile changing means for changing the profile, and the encryption means for encrypting the table by a predetermined algorithm , the table generating means Generates the table so that the profile before and after the change by the table approximates, and when the profile after the change is used for print output, the total amount of ink for the print output is regulated. It is characterized by that.
[0008]
For example, the table generating means further stores information indicating a processing order when subtracting data in the profile and information indicating a position of the data in the table. .
[0009]
The information processing apparatus further includes a transmission unit configured to transmit a profile whose data has been changed by the profile changing unit and a table encrypted by the encryption unit to an external device.
[0010]
Further, the decrypting means for decrypting the table encrypted by the encrypting means, and the data in the profile changed by the profile changing means, the value before the change by the profile changing means based on the decrypted table And a profile restoration means for restoring to the above.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment according to 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 this embodiment. As shown in the figure, this system includes an image input unit 10, an image processing unit 20, and an image output unit 30, and the color conversion unit 21 in the image processing unit 20 refers to the ICC profile in the 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 profile encryption and decryption, which is a feature of the present embodiment. The ICC profile encrypted by the profile encryption unit 23 can be transmitted to the 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]
Each of the above components in the image processing unit 20 is centrally controlled by a control unit 26 including a CPU, a ROM, a RAM, and the like. Reference numeral 27 denotes a GUI unit that performs settings related to data security (encryption or the like) in the present embodiment, which will be described later, based on the control of the control unit 26.
[0015]
GUI Screen FIG. 2 is a diagram showing a display screen example of the GUI 27 for color matching setting in this system. The GUI controls on / off of the color matching process. As shown in the figure, there are two setting items for the processing system in the input color space: the RGB input system and the CMYK input system. Intent (intent) indicating the profile specification and matching method in each color space ) Can be set. Since the profile of the output printer is related to the connected printer, it can be set as appropriate in cooperation with the print mode.
[0016]
In the GUI shown in the figure, when the cursor is moved to the “profile management” button 107, a pull-down menu is displayed, and “RGB input”, “CMYK input”, or “printer setting” can be selected. When any of these items is selected, a “profile management” sheet shown in FIG. 3 is displayed.
[0017]
The ICC profiles in this embodiment are configured to be selected and registered as appropriate from the profile storage memory 22, and the available ICC profiles are displayed as a list 201 on the “profile management” sheet shown in FIG. ing. When a new profile is added, after the ICC profile is stored in the profile storage memory 22, the “Register” button 202 on the “Profile Management” sheet is pressed. When the new ICC profile becomes available, the information is displayed in the list 201. In order to delete a registered profile, it is only necessary to select an ICC profile displayed in the list 201 and then press the “delete” button 203.
[0018]
In this embodiment, when setting the security of the ICC profile, the target ICC profile is selected from the list 201 on the “profile management” sheet shown in FIG. 3, and the “security setting” button 204 is pressed. To do. Thereby, the “security setting” sheet shown in the lower part of FIG. 3 is displayed, and the encryption and decryption of the file itself can be operated. Details of profile encryption and decryption processing in this embodiment will be described later.
[0019]
Encrypted scan table The present embodiment is characterized in that an encrypted scan table is used when an ICC profile is encrypted and decrypted. This encryption scan table is generated in the profile storage memory 22 at the time of profile encryption processing.
[0020]
FIG. 4 shows the configuration of the encryption scan table. As shown in the figure, the encryption scan table is composed of a plurality of field data. Each field has an ID indicating a data processing order, an offset address indicating the position of data to be processed, and a processing target. A displacement amount indicating subtraction or addition amount with respect to data is stored. In the present embodiment, the offset address and the displacement amount are each randomly generated within a predetermined range, thereby generating one encrypted scan table.
[0021]
In the present embodiment, when encrypting a profile, the encryption scan table is encrypted (or decrypted) by a predetermined algorithm. At this time, a change is made to perform subtraction processing for the set amount of displacement on the substantial data constituting the 3D-LUT of the profile. When this 3D-LUT is decrypted, the original data can be reproduced by performing addition processing for the amount of displacement with reference to the encryption scanning table.
[0022]
Encryption Process The ICC profile encryption process in this embodiment will be described below with reference to the flowchart shown in FIG.
[0023]
First, in step S111, a profile to be encrypted is read. In step S112, an encryption flag indicating whether or not a subtraction process (encryption subtraction process) using the encryption scan table has been performed is searched for in the profile. Note that the flag information in the profile is used as the encryption flag.
[0024]
The determination result is received in step S113, and it is determined whether or not the encrypted subtraction process can be performed on the read profile. That is, in this embodiment, if the flag information indicates that the encryption subtraction process has been completed, it is determined that encryption is not possible. Thereby, it is possible to avoid performing the encryption subtraction process again for the profile that has already been subjected to the encryption subtraction process.
[0025]
If the encryption subtraction process is possible, the process proceeds to step S114 to generate an encryption scan table. In step S115, the field data of the generated encrypted scan table is referred to, the offset address and the displacement amount data are extracted in the order of the stored ID numbers, and appropriately subtracted from the 3D-LUT constituting the profile. Process.
[0026]
In step S116, general initialization processing necessary for encryption is performed, and then the encryption scan table is encrypted in step S117. The encryption method here is not particularly limited, and any known encryption method can be applied.
[0027]
Then, after the tag data of the profile is reconstructed in step S118, flag data indicating that the profile encryption subtraction process has been performed is embedded in the tag data in step S119. In step S120, the ICC profile is reconstructed using the tag data.
[0028]
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.
[0029]
As described above, in the present embodiment, the profile encryption / subtraction process, that is, the subtraction process for the 3D-LUT and the scan table encryption process are performed according to the flowchart shown in FIG.
[0030]
Decryption Processing In this embodiment, when it is determined that the set ICC profile is encrypted at the start of printing, the decryption processing is performed inside the system. Hereinafter, the decoding process in the present embodiment will be described with reference to the flowchart of FIG.
[0031]
First, in step S211, the ICC profile set for printing is read, and in step S212, the encryption flag is searched. In step S213, it is determined based on the encryption flag whether or not the profile needs to be decrypted. That is, if the encryption flag indicates that encryption has been performed, it is determined that it is necessary to perform decryption processing of the encryption scan table and addition processing (decryption addition processing) of the 3D-LUT.
[0032]
If it is determined that decryption is necessary, the encryption scan table is cut out in step S214. After performing general initialization processing necessary for decryption addition processing in step S215, encryption is performed in step S216. The decoding process of the conversion scan table is performed.
[0033]
In step S217, the field data of the decoded scanning table is referred to, the offset address and the displacement amount data are extracted in the order of the stored ID numbers, and the addition process is appropriately performed on the 3D-LUT of the profile.
[0034]
Next, in step S218, the tag data of the profile is reconstructed. In step S219, the profile is reconstructed using the tag data, and in step S220, the decoded ICC profile is set for the system.
[0035]
Note that the ICC profile decrypted in the present embodiment is expanded only to internal resources (work memory, etc.) in which the present system is operating so as not to be referred to from the outside.
[0036]
As described above, according to the present embodiment, only the LUT tag portion of the ICC profile is encoded. As a result, the ICC profile can be made non-readable without altering its internal data, so it can be safely used via a network.
[0037]
Also, the internal data of the encrypted ICC profile itself has a value close to the original before encryption, and each data value is subtracted, so this profile decryption function Even when the profile is used in a system that does not have a print quality, printing processing with a minimum image quality can be guaranteed without exceeding the restriction on the total amount of ink in the printer engine of the system.
[0038]
<Other embodiments>
Note that the present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, and a printer), and a device (for example, a copying machine and a facsimile device) including a single device. You may apply to.
Another object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium. Needless to say, this can also be achieved by reading and executing the program code stored in.
[0039]
In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.
[0040]
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.
[0041]
In addition, by executing the program code read by the computer, 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 part of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.
[0042]
Further, after the program code read from the storage medium is written to a memory provided in 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 the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.
[0043]
【The invention's effect】
As described above, according to the present invention, it is possible to appropriately encrypt an ICC profile by generating an encryption scan table for the ICC profile and encrypting it.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a printing system according to an embodiment.
FIG. 2 is a diagram showing an example of a GUI screen for performing color matching setting in the present embodiment.
FIG. 3 is a diagram showing an example of a GUI screen for performing profile security settings in the present embodiment.
FIG. 4 is a diagram showing a configuration example of an encryption scan table in the present embodiment.
FIG. 5 is a flowchart showing encryption processing in the present embodiment.
FIG. 6 is a flowchart showing a decoding process in the present embodiment.
[Explanation of symbols]
10 Image input section
20 Image processing section
21 color converter
22 Profile storage memory
23 Profile encryption part
24 Profile decryption unit
25 Communications department
26 Control unit
27 GUI section
30 Image output section
40 network

Claims (15)

An image processing apparatus for changing a color matching profile,
Table generating means for generating a table storing information on the amount of subtraction when subtracting data in the profile;
Profile changing means for changing the profile by subtracting the data in the profile based on the table ;
Encrypting means for encrypting the table by a predetermined algorithm ,
The table generating means includes
Generating the table so that the profile before and after the change by the table approximates, and when the profile after the change is used for print output, the total amount of ink for the print output is regulated. A featured image processing apparatus. Claim wherein the table generating unit may further the information indicating the order of processing when the subtraction processing for the data in the profile, and information indicating the position of the data, and storing, in the table the image processing apparatus according to 1. Data in the profile, the image processing apparatus according to claim 1, characterized in that the 3DLUT of the profile.   The image processing apparatus according to claim 1, wherein the profile changing unit embeds information indicating that the profile has been changed in tag data of the profile changed based on the table. Storage means for storing a plurality of profiles;
Selection means for selecting a profile to be changed from the storage means;
The image processing apparatus according to claim 1 , further comprising: The image processing apparatus according to claim 1 , further comprising a profile update unit that updates the profile stored in the storage unit by replacing the profile with data changed by the profile change unit. The image processing apparatus according to claim 1 , further comprising a transmission unit configured to transmit a profile whose data has been changed by the profile changing unit and a table encrypted by the encryption unit to an external device. And decryption means for decrypting the table encrypted by the encryption means;
And profile restoring means for restoring the value before the change by said profile changing means based on the data of the changed in the profile, the decoded table in the profile changing means,
The image processing apparatus according to claim 1 , further comprising: The profile restoration means restores the value before the change by performing addition processing on the data in the profile changed by the profile change means based on the information about the subtraction amount stored in the table. The image processing apparatus according to claim 8 . 9. The image processing apparatus according to claim 8, wherein the decoding unit and the profile restoration unit operate when there is information indicating that the profile has been changed in the tag data of the profile. Furthermore, color matching means for performing color matching using the profile restored by the profile restoration means,
Image output means for outputting image data after color matching by the color matching means;
The image processing apparatus according to claim 8, further comprising: An image processing system in which a plurality of image processing apparatuses are connected via a network,
The first image processing apparatus is an image processing apparatus that changes a color matching profile ,
Table generating means for generating a table storing information on the amount of subtraction when subtracting data in the profile;
Profile changing means for changing the profile by subtracting the data in the profile based on the table ;
Encryption means for encrypting the table with a predetermined algorithm;
Has a profile that is changed by the profile change means, and transmission means for transmitting the encrypted table in the second image processing apparatus via the network by the encryption means,
The table generating means includes
Generating the table so that the profile before and after the change by the table approximates, and when the profile after the change is used for print output, the total amount of ink for the print output is regulated,
The second image processing apparatus includes:
Receiving means for receiving the modified profile and the encrypted table transmitted from the transmitting means;
Decryption means for decrypting the encrypted table;
Profile restoration means for restoring the profile by performing addition processing on the data in the modified profile based on the decrypted table;
An image processing system comprising: An image processing apparatus control method for changing a color matching profile,
A table generation step for generating a table storing information on the amount of subtraction when subtracting data in the profile;
A profile changing step for changing the profile by subtracting the data in the profile based on the table ;
An encryption step of encrypting the table with a predetermined algorithm ,
The table generation step includes
Generating the table so that the profile before and after the change by the table approximates, and when the profile after the change is used for print output, the total amount of ink for the print output is regulated. Characteristic control method. An image processing apparatus for changing a color matching profile,
Table generating means for generating a table storing information on the amount of subtraction when subtracting data in the profile;
Profile changing means for changing the profile by subtracting the data in the profile based on the table;
Encrypting means for encrypting the table by a predetermined algorithm,
The table generating means includes
An image processing apparatus that generates the table so that a total amount of ink for printing output is regulated when the profile after the change is used for printing output . An image processing apparatus control method for changing a color matching profile,
A table generation step for generating a table storing information on the amount of subtraction when subtracting data in the profile;
A profile changing step for changing the profile by subtracting the data in the profile based on the table;
An encryption step of encrypting the table with a predetermined algorithm,
The table generation step includes
A control method comprising: generating the table so that a total amount of ink for printing output is regulated when the changed profile is used for printing output .

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