Image processor, its control method, and image processing system

The present invention relates to an image processing apparatus for encrypting a profile for color matching, a control method thereof, and an image processing system.

PROBLEM TO BE SOLVED: In recent years, a color printer capable of color matching processing using a profile (ICC profile) or the like proposed by ICC (International Color Consortium) has 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 technique is a device-independent color space (device-independent color space) and device-specific color space for image data using a profile in which color conversion characteristics corresponding to devices constituting the printing system are filed. Optimal color reproduction in the device is realized by mutual conversion with the color space (device-dependent color space) of.

[0004] [Problems to be Solved by the Invention] It is conceivable that the ICC profile required to realize the color matching as described above is 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, the internal data or the like may be falsified, and there is concern about safe use. Moreover, even if the data itself is made unreadable, there is currently no optimal means.

[0005] The present invention has been made in view of the above problems, and an object of the present invention is to provide an image processing device for appropriately encrypting an ICC profile, a control method thereof, and an image processing system.

[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, a profile for color matching<u style="single">Change</u>An image processing device that performs the above profile.<u style="single">Stores information about the subtraction amount when subtracting processing is performed on the data in</u>Table generation means to generate a table and<u style="single">By subtracting the data in the profile based on the table, the profile can be obtained.</u>A profile changing means for changing and an encryption means for encrypting the table by a predetermined algorithm.<u style="single">The table generating means regulates the total amount of ink for the print output so that the profiles before and after the change by the table are approximated and the changed profile is used for the print output. To generate the table</u>It is characterized by that.

[0008] For example, the table generation means is<u style="single">In addition</u>Data in the profile<u style="single">Information indicating the processing order when performing subtraction processing and information indicating the position of the data are stored in the table.</u>It is characterized by that.

[0009] Further, by the profile changing means.<u style="single">data</u>Is characterized by having a transmission means for transmitting the modified profile and a table encrypted by the encryption means to an external device.

[0010] Further, in the decryption means for decrypting the table encrypted by the encryption means and the profile changed by the profile changing means.<u style="single">data</u>, Said<u style="single">Decrypted</u>It is characterized by having a profile restoration means for restoring the value before the change by the profile changing means based on the table.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment according to the present invention will be described in detail with reference to the drawings.

&lt;First Embodiment&gt; System configuration diagram 1 is a block diagram showing an outline configuration of a printing system according to the present embodiment. As shown in the figure, this system consists of 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. Then, color matching is performed between the image input unit 10 and the image output unit 30.

[0013] The image processing unit 20 has a profile encryption processing unit 23 and a profile decryption processing unit 24, and performs encryption and decryption of the profile, which is a feature of the present embodiment. The ICC profile encrypted by the profile encryption unit 23 can be transmitted onto the network via the communication unit 25. If the ICC profile received from the network 40 via the communication unit 25 is encrypted, it is decrypted by the profile decoding unit 24 and then referred to by the color conversion unit 21.

[0014] Each of the above configurations in the image processing unit 20 is collectively controlled by a control unit 26 including a CPU, ROM, RAM, and the like. Further, 27 is a GUI unit, and based on the control of the control unit 26, settings related to data security (encryption, etc.) in the present embodiment described later are performed.

GUI screen FIG. 2 is a diagram showing an example of a display screen of GUI 27 for color matching setting in this system. This GUI controls the on / off of the color matching process. As shown in the figure, there are two processing system setting items in the input color space, RGB input system and CMYK input system, and intent (intent) indicating profile specification and matching method in each color space. ) Can be set. Further, since the profile of the output printer is related to the connected printer, it is possible to appropriately set it in cooperation with the print mode and the like.

[0016] In the GUI shown in the figure, when the cursor is placed on the "profile management" button 107, a pull-down menu is displayed, and one of "RGB input", "CMYK input", and "printer setting" can be selected. .. Then, when any of these items is selected, the "Profile Management" sheet shown in FIG. 3 is displayed.

[0017] The ICC profile in the present embodiment is configured to be appropriately selected and registered from the profile storage memory 22, and the available ICC profiles are listed 201 on the "profile management" sheet shown in FIG. Is displayed as. To add a new profile, save the ICC profile in the profile storage memory 22 and then press the "Register" button 202 on the "Profile management" sheet. Then, when this new ICC profile becomes available, the information is displayed in Listing 201. To delete the registered profile, select the ICC profile displayed in Listing 201 and click the "Delete" button 203.

[0018] In the present embodiment, when setting the security of the ICC profile, select the target ICC profile from the list 201 on the "profile management" sheet shown in FIG. 3, and then click the "security setting" button. Press 204. As a result, the "security setting" sheet shown at the bottom of FIG. 3 is displayed, and the encryption and decryption of the file itself can be operated. The details of the profile encryption and decryption processing in this embodiment will be described later.

Encrypted Scanning Table The present embodiment is characterized in that the encrypted scanning table is used when encrypting and decrypting the ICC profile. This encrypted scanning table is generated in the profile storage memory 22 during the profile encryption process.

FIG. 4 shows the configuration of the encrypted scanning 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 the data processing order, an offset address indicating the position of the data to be processed, and a processing target. A displacement amount, which indicates the amount of subtraction or addition to the data, is stored. In the present embodiment, one encrypted scanning table is generated by randomly generating the offset address and the displacement amount within a predetermined range.

[0021] When encrypting the profile in the present embodiment, the encryption scanning table is encrypted (or decrypted) by a predetermined algorithm. At that time, a change is added in which the subtraction processing for the set displacement amount is performed on the substantial data constituting the 3D-LUT of the profile. When decoding this 3D-LUT, the original data can be reproduced by referring to the encrypted scanning table and performing the addition processing for the displacement amount.

Encryption processing The ICC profile encryption processing according to the present embodiment will be described below with reference to the flowchart shown in FIG.

[0023] First, in step S111, the profile to be encrypted is read. Subsequently, in step S112, an encryption flag indicating whether or not a subtraction process (encryption subtraction process) using the encryption scanning table has been performed is searched in the profile. As this encryption flag, the flag information in the profile is used.

[0024] Then, the determination result is received in step S113, and it is determined whether or not the encrypted subtraction process for the read profile is possible. In the present embodiment, that is, if the flag information indicates that the encryption / subtraction processing has been completed, it is determined that encryption is not possible. As a result, it is possible to prevent the profile that has already been subjected to the encryption / subtraction processing from being subjected to the encryption / subtraction processing again.

If the encryption / subtraction process is possible, the process proceeds to step S114 to generate an encryption scan table. Then, in step S115, the offset address and the displacement amount data are extracted in the order of the stored ID numbers with reference to each field data of the generated encrypted scanning table, and appropriately subtracted from the 3D-LUT constituting the profile. Perform processing.

[0026] Then, in step S116, after performing the general initialization process required for encryption, the encryption scan table is encrypted in step S117. The encryption method here is not particularly limited, and any well-known encryption method can be applied.

[0027] Then, after reconstructing the tag data of the profile in step S118, flag data indicating that the profile encryption / subtraction process has been performed in step S119 is embedded in the tag data. Then, in step S120, the ICC profile is reconstructed using the tag data.

[0028] Then, in step S121, it is checked whether or not the read ICC profile itself can be overwritten, and 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 3D-LUT subtraction process and the scanning table encryption process is performed according to the flowchart shown in FIG.

Decryption process In the present embodiment, if it is found that the set ICC profile is encrypted at the start of printing, the decryption process is performed inside the system. Hereinafter, the decoding process in the present embodiment will be described with reference to the flowchart of FIG.

First, in step S211, the ICC profile set for printing is read, and in step S212, the encryption flag is searched. Then, in step S213, it is determined whether or not it is necessary to perform the decryption process of the profile based on the encryption flag. That is, if the encryption flag indicates that the encryption has been completed, it is determined that it is necessary to perform the decryption processing of the encryption scanning table and the addition processing of the 3D-LUT (decryption addition processing).

[0032] When it is determined that decryption is necessary, the encrypted scanning table is cut out in step S214, and in step S215, after performing the general initialization process required for the decryption addition process, the step is performed. Decrypt the encrypted scan table with S216.

[0033] Then, in step S217, each field data of the decoded scanning table is referred to, the offset address and the displacement amount data are taken out in the order of the stored ID numbers, and the 3D-LUT of the profile is appropriately added. I do.

Next, the tag data of the profile is reconstructed in step S218, the profile is reconstructed using the tag data in step S219, and then the decrypted ICC profile is applied to the system in step S220. set.

The ICC profile decoded in the present embodiment is expanded only to the internal resource (work memory, etc.) in which the 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 unreadable without falsifying its internal data, so that it can be safely used even via a network.

[0037] Further, since the internal data itself of the encrypted ICC profile has a value close to the original before encryption, and each data value is subjected to a subtraction process, this profile. Even when the profile is used in a system that does not have the decoding function of the above, it is possible to guarantee the printing process with the minimum image quality without exceeding the regulation of the total amount of ink in the printer engine of the system.

&lt;Other Embodiments&gt; Even if the present invention is applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), the present invention is a device composed of one device (for example). For example, it may be applied to a copier, a facsimile machine, etc.). Another object of the present invention is to supply a storage medium in which a program code of software that realizes the functions of the above-described embodiment is recorded to a system or device, and a computer (or CPU or MPU) of the system or device is a 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 function of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

[0040] Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a non-volatile memory card, and a ROM. Etc. can be used.

[0041] Further, by executing the program code read by the computer, not only the function of the above-described embodiment is realized, but also the OS (operating system) running on the computer based on the instruction of the program code. ) Etc. perform a part of the actual processing, and it goes without saying that the processing may realize the function of the above-described embodiment.

[0042] Further, after the program code read from the storage medium is written in the memory provided in the function expansion board inserted in the computer or the function expansion unit connected to the computer, based on the instruction of the program code, the program code is written. Needless to say, there are cases where the function expansion board, the CPU provided in the function expansion unit, or the like performs a part or all of the actual processing, and the processing realizes the functions of the above-described embodiment.

[Effect of the Invention] As described above, according to the present invention, it is possible to appropriately encrypt the ICC profile by generating an encrypted scanning table for the ICC profile and encrypting the table. ..

BRIEF DESCRIPTION OF THE DRAWINGS [Fig. 1] Fig. 1 is a block diagram showing an outline configuration of a printing system according to the present embodiment.

FIG. 2 is a diagram showing an example of a GUI screen for performing color matching settings in the present embodiment.

FIG. 3 is a diagram showing an example of a GUI screen for setting profile security in the present embodiment.

FIG. 4 is a diagram showing a configuration example of an encrypted scanning table according to the present embodiment.

FIG. 5 is a flowchart showing an encryption process according to the present embodiment.

FIG. 6 is a flowchart showing a decoding process according to the present embodiment.

[Description of code] 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