JP2001218040A - Picture processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a picture processing system detecting whether information whose copy is inhibited is buried in picture data or not at high speed. SOLUTION: When the buried position of information whose copy is inhibited is detected, picture data whose resolution is reduced is used. When the position is detected, a peripheral picture is cut at every block based on a pattern size and it is compared with a pattern picture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image processing method and a recording medium of an information processing apparatus capable of reading a document by a scanner and printing image data by a printer.

[0002]

2. Description of the Related Art In recent years, the performance of a color image reading apparatus (hereinafter, referred to as a color scanner) using a CCD or the like and a color printer have been improved. Therefore, there is an increasing danger that a document whose copy is prohibited is duplicated by outputting to a color printer. In order to prevent such copying of a copy-prohibited object, a color copier, which is a combination of a color scanner and a color printer, often incorporates a forgery prevention device that recognizes a copy-protected document and prohibits copying. Is coming.

[0003]

However, a forgery prevention device used in a color copying machine operates only at the time of a copying operation, and if reading by a scanner and printing of the read image data are separately processed, It was easy to duplicate. That is, there is a serious problem in that once a copy-inhibited document is read by a color scanner and the result is output by a color copier or another color printer via a controller, the copy-inhibited document is easily forged. .

Therefore, a copy inhibition control method is considered in which it is determined from a scanned image data or a print image data stored in a memory whether a document is a copy inhibition document, and if so, these image data are changed. Can be However, if all the image data stored in the memory is processed as it is, there is a disadvantage that the processing time becomes longer and the original scanning and printing operations become longer.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems of the prior art, and has as its object to provide an image processing system capable of detecting at a high speed whether image data is image data of a copy-inhibited document. is there.

[0006]

In order to achieve the above object, an image processing apparatus according to the present invention comprises a detecting means for detecting whether specific information is included in image data, and a detecting means for detecting the specific information. Image processing means for performing predetermined processing on image data detected to contain information, wherein the image data transfer processing in the image processing system includes the image data Wherein the detection means performs the detection for each of the plurality of block units.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) Hereinafter, the present invention will be described in detail based on a preferred embodiment with reference to the drawings. FIG. 1 is a block diagram illustrating an example of an image processing system according to an embodiment of the present invention. In the following embodiments, it is assumed that the system recognizes a pattern used as a digital watermark and a method of embedding the pattern in advance.

[0008] The image processing system according to the present embodiment comprises:
The information processing apparatus 100 includes a scanner 111 and a printer 114 connected to the information processing apparatus 100.

In the present system, a document image read by the scanner 111 can be printed out by the printer 114, and the document can be copied. Further, the image transmitted via the LAN 115 such as 10Base-T is transmitted to the printer 11.
4 and, conversely, an image read by the scanner 111 can be sent to another information processing apparatus connected to the LAN 115 via the LAN 115. The scanner 111 is, for example, a color scanner.
After scanning a CD line sensor to optically read a document placed on a document table, the document is converted into an electric signal (photoelectric conversion) and read. The image signal includes a plurality of color components, for example, R, G, B
, And each is multi-value data of 8 to 12 bits.

The CPU 101 is, for example, a high-speed RISCCP
U and the scanner 111 which constitutes the system
And the printer 114, and the information processing apparatus 100. Control between the CPU 101 and each block in the information processing apparatus 100 and image data are performed by exchanging data having a packet structure. In FIG. 1, thick white arrows indicate the flow of packet data.

The image processing system according to the present embodiment has a user interface such as an operation panel and a display device not shown in FIG.

(Relationship Between Packet Data and Image) Next, the relationship between packet data and an image in the present embodiment will be described with reference to FIG. FIG. 2A shows the original image, and the hatched portion in the upper left corner shows the division of the image for each tile (Tile) of 32 pixels × 32 pixels as shown in FIG. 2B. The image data for one tile is handled as a packet of one image data. FIG. 2 (B)
The numbers from 0 to 1023 are sequentially defined for the pixels in one tile as shown in FIG.

(Packet Format) FIGS. 3 and 5 show data formats of packets used in the present embodiment. The system according to the present embodiment uses two types of packets, an image packet shown in FIG. 3 and a command packet shown in FIG. Each packet has a fixed length of 34 bits
He is composed of a der section and a variable-length DATA section.
The configuration is such that the command packet and the image packet are distinguished by the value of the first bit (bit 0) of the adder part.

In the case of an image packet, a 34-bit Hea
The der section is defined as shown in FIG. 3, and bit [4: 1] is an ID code indicating the destination of the packet. Also, bit
[6: 5] are color information bits indicating the color of the image data included in the data portion.
Indicates which of the colors in the MYK format. The remaining bits are the start X, Y of the image data contained in this packet.
The coordinates (for example, indicating the upper left position of the tile).

The Data portion (Ima) of the image data packet
GeData section) has a configuration shown in FIG.
It has a length of bytes. (1) of FIG.
This is the case of the GB (Blue, Green, Red) format, and (2) is the CMYK (Cyan, Magenta, Y) format.
(ello, Black) format.
In this embodiment, the image data is JPEG-compressed and the data length is variable.
Are provided for each color of 3 bits.

On the other hand, the header part of the command packet is defined as shown in FIG. Bit of Header section
[4: 0] is the same as the image packet, and bit [5]
Indicates whether the command is Read or Write of the CPU. At the time of reading, first, a forward packet for read is output from the first packet converter 102 to the system bus bridge (SBB) 104, and a return packet resulting from the read returns to the first packet converter 102 via the SBB 104. come. Also, a maximum of 16 commands can be sent in one packet, and the number of commands contained in the packet is Comm in bits [9: 6] of the Header section.
Defined as and Number.

The Data portion (Comm) of the command packet
andData portion) has a maximum length of 128 bytes and has a configuration shown in FIG. That is, one command is composed of a 4-byte address and 4-byte data,
Commands 0 to 15 are arranged in order from command 0. However, the outgoing command packet has only an address and no data.

(Data Flow During Copying) Next, the flow of data when an image read by the scanner 111 is copied by the printer 114 will be described. Scanner 111
Is raster data, and the raster data is subjected to image processing by the scanner image processing unit 112.

The data subjected to image processing by the scanner image processing unit 112 is JPEG-compressed by the raster conversion unit 109 and then converted into the above-described image packet. At this time, the destination of the packet is not the printer 114 but the SDRAM 10
6 is set. The image packet is sent to a system bus bridge (SBB) 104.

The SBB 104 sends out the input packet data according to the destination defined in the packet data. At this time, since the destination is the SDRAM 106, the data is written from the SBB 104 to the SDRAM 106 via the second packet converter 105.

At the time of double-sided copying, when one page of image data written in the SDRAM 106 is collected, a hard disk drive (hereinafter, HDD) 108 stores the SBB 10
4 via the hard disk controller 107.

After the writing of the image for one page to the SDRAM 106 is completed, the image data is sequentially read from the SDRAM 106 and sent to the raster conversion unit 109 via the SBB 104. This data transfer is performed by the CPU 1
01 to the SBB via the first packet converter 102
This is performed by the SBB 104 according to the command sent to the SBB 104.

The raster conversion unit 109 expands the image data stored in the Data portion of the sent image packet in a JPEG-compressed state, converts the image data into raster data using the SDRAM 110, and outputs the raster image data to the printer image processing unit 1.
13 is output. The image data processed by the printer image processing unit 113 is sent to the printer 114 and printed on paper.

(Data Flow During Printing) Next, LA
The image data sent via N115
4 will be described. LA
The image data sent in N115 is converted by the LAN controller 103 into an image packet whose destination is the SDRAM 106, and is written to the SDRAM 106 via the SBB 104 and the packet conversion unit 105.

When one page of the image data written in the SDRAM 106 accumulates, it is sequentially transferred to a hard disk drive (hereinafter, HDD) 108 via the SBB 104 and the hard disk controller 107. This is so that when a paper jam occurs in the printer 114 during printing, it is possible to automatically recover from a place where printing was not possible after the paper jam was cleared.

When the writing of the image for one page to the SDRAM 106 is completed and the backup to the HDD 108 is completed, the image data is sequentially read from the SDRAM 106, and the packet data conversion unit 105 and the SBB 104
Is also sent to the raster conversion unit 109 via. These data transfers are performed by the CPU 101 to the packet converter 102.
According to the command sent to SBB 104 via
This is performed by the BB 104.

The raster converter 109 expands the image data stored in the Data portion of the sent image packet in a JPEG-compressed state, converts the image data into raster data using the SDRAM 110, and outputs the raster data to the printer image processor 1.
13 is output. The image data processed by the printer image processing unit 113 is sent to the printer 114 and printed on paper.

(Forgery Prevention Judgment) The system of this embodiment has a forgery prevention judgment function for judging whether read data or data for printing is a copy-inhibited original. Hereinafter, the procedure will be described. This determination function is executed by the CPU 101.

First, image data on the SDRAM 106 is divided into blocks, and Fourier transform is performed for each block to extract frequency components. This block is composed of an integral number of 32 pixels × 32 pixels, which is a unit of one packet. As described above, by performing processing in units of packets, processing is performed in units equal to data transfer units in the system, and processing can be performed at high speed. Image data in the frequency domain obtained as a result of the frequency component extraction processing is separated into an amplitude spectrum and a phase spectrum, and a registration signal included in the amplitude spectrum is detected.

This registration signal is disadvantageous in that the embedding of a signal in a low-frequency component is more likely to be recognized as noise from human visual characteristics than the embedding of a signal in a high-frequency component, and a lossy compression method such as JPEG compression. Has the effect of a low-pass filter, the high-frequency component is removed by the compression / expansion processing. And is embedded with an impulse signal to a frequency of an intermediate level which is not removed by irreversible compression and decompression and is equal to or higher than the first frequency level.

In the detection of the registration signal, an impulse signal in the above-mentioned intermediate level frequency domain included in the amplitude spectrum is extracted.

The scaling ratio of the digital image data is calculated from the coordinates of the extracted impulse signal. In the present embodiment, it is assumed that the CPU 101 recognizes in advance which frequency component of the unscaled detection target image has the impulse signal embedded therein.

The scaling ratio can be calculated from the ratio between the previously recognized frequency and the frequency at which the impulse is detected. For example, if the frequency recognized in advance is a and the frequency of the signal of the detected impulse is b, it can be understood that a / b scaling is performed at the time of reading. This is a known property of the Fourier transform.

The size of a pattern for detecting a digital watermark included in digital image data is determined based on the scaling ratio, and convolution using this pattern is performed to detect a digital watermark included in digital image data.

Further, since the information indicating the position where the digital watermark is embedded can be easily detected even with low resolution image data, the position information is image data obtained by thinning out pixels (for example, data obtained by thinning out one pixel for every two pixels). After detecting in advance, an image at a specific position where it is detected that an electronic watermark is embedded is cut out from image data in which no pixel is thinned out, and a digital watermark is detected.

At this time, the cutout size of the image is obtained by cutting an integer packet of 32 pixels × 32 pixels from the center of a specific position. For example, if the image data is image data obtained by reading a bill, it is assumed that the size of the embedded digital watermark is determined in advance by a standard or the like. If the size is 10 mm × 10 mm,
For a 600 dpi resolution image, 32 pixels are approximately 1.4.
mm, it suffices to cut out 15 × 15 slightly larger tiles of 32 × 32 pixels. As a result, the number of images to be handled can be minimized, and the processing speed can be increased because the images are handled in packets.

The digital watermark may be added to any component of the digital image data. In the present embodiment, the digital watermark is added to the blue component which is most insensitive to human vision. Pattern detection is performed on the blue component.

When a digital watermark in which information is embedded in a specific frequency component is embedded in the digital image data instead of adding an electronic watermark to the visible color component constituting the digital image data, Processing for detecting a digital watermark at a specific frequency after Fourier transform into image data may be performed.

(Forgery Prevention Determination Flow) A processing flow of forgery prevention determination at the time of copying will be described with reference to FIG. In step S701, the CPU 101 instructs the scanner 111 to start scanning. Then, next, step S702
When the image data is written to the SDRAM 106 at
In step S703, the PU 101 reads the data on the SDRAM 106 and performs the above-described digital watermark extraction processing.

From the information of the digital watermark extracted in step S703, it is determined in step S704 whether or not the image is prohibited from being copied. If so, step S705 is performed.
After performing forgery prevention control processing (described later) in step S7,
At 06, the printer is started, and the sequence proceeds to a print start sequence. If it is determined in step S704 that the image is not a copy-prohibited image, the process immediately proceeds to step S706 to execute a print start sequence.

(Forgery Prevention Control Processing) Step S7 in FIG.
The forgery prevention control process of 05 will be described in detail. FIG.
FIG. 4 is a diagram illustrating an example of a forgery prevention process performed on a printer output, for example, an example of a forgery prevention process on a banknote whose copying is prohibited. FIG. 8A shows an original image read from the scanner 111, and FIG. 8B shows an image after the forgery prevention processing.

FIG. 9 is a characteristic diagram showing an example of the forgery prevention process of FIG. 8, in which the vertical axis indicates image data G (Green) and the horizontal axis indicates the scanning position. In FIG. 9, I indicates the original image data, and II indicates the image data after the processing. In FIG. 9, the vertical axis represents the Green data of a part of the image, and the horizontal axis represents the main scanning position of the image.
The image data on the vertical axis represents 256 gradations from 0 to 255, and the image becomes brighter as it approaches 255.

The image data I is the original image before the processing
This represents data stored in the RAM 106. If the image data is reduced by a certain value for all the pixels of the image data, image data II is generated. Then, among the image data II, all the data below “0” become “0”, so that the information of the change of the image is lost. By performing this processing on Red and Blue other than Green, the image shown in FIG. 8B is generated as an output image candidate. This processing is performed by the packet converter 10 according to a command packet instruction from the CPU 101.
5 is performed by rewriting the contents of the SDRAM 106 at high speed. Further, in the present embodiment, it is not possible to return the image after the main processing to the image before the main processing.

FIG. 10 is a view showing an example of a screen displayed on a user interface (not shown) of the system of the present embodiment. The image data read from the scanner 111 is the image data to be prohibited from duplication. Corresponds to an example of a warning screen displayed to the user when it is recognized.

In FIG. 10, the button BT1 is selected and instructed by the user to approve the content according to the displayed warning and output an image. Button BT2
Is selected by the user to approve the content according to the displayed warning and avoid image output.

FIG. 11 is a diagram showing an example of log information stored in the HDD 108 shown in FIG. 1, and is composed of information on the type, issue country, issue number, and value of the copy prohibited image. These pieces of information can be created from the image processing of the read image and the information of the copy-prohibited object stored in advance in the forgery prevention control processing shown in step S705 of FIG.

(Forgery Prevention Control Processing Flow)
The forgery prevention control process will be described in detail with reference to the flowchart shown in FIG. FIG. 12 is a flowchart illustrating an example of the forgery prevention process in the image processing system according to the present embodiment, and corresponds to the forgery prevention control process of step S705 illustrated in FIG.

First, in step S601, image processing for preventing forgery is performed on image data on the SDRAM 106 as an image memory. In this embodiment, FIG.
The original image shown in FIG. 8B is subjected to the processing, and FIG.
, For example, an image that is painted in gray. The processing principle is as described with reference to FIG.

Next, in step S602, the user input screen (warning dialog) shown in FIG. 10 is displayed on a user interface (not shown). That is, when there is a possibility that the image input from the scanner 111 is a copy-inhibited document, the user can be made to confirm whether or not the image is actually printed out from the printer.

In step S603, it is checked whether the button on the user input screen, that is, whether the user input is "Yes" corresponding to the button BT1 or "No" corresponding to the button BT2, is determined. Yes"
(If printing out), the HDD 10
A history as shown in FIG. 11 is stored in FIG. 8, and the process is terminated. As a result, the fact that the copy-inhibited original has been read later can be left as evidence, and thereafter, it is extremely easy to confirm whether or not a forgery prevention target original has been input.

On the other hand, if it is determined in step S 603 that “NO” has been selected and instructed, that is, if the image is not to be printed out, in step S 604,
The SDRAM 106 storing the image is released, the image is discarded, and the process ends. In this case, upon entering the printer start process in S706 of FIG. 7, the process is immediately skipped and the process ends without printing.

In this control, instead of printing the image read by the scanner 111 by the printer 114, LA
The same applies to the case of sending to another device such as a personal computer in N115. That is, if it is determined in step S704 in FIG. 7 that the read image is a copy-inhibited image, the process proceeds to step S705 corresponding to the forgery prevention control process in step S705.
The processing from step 601 is executed, and in step S603,
If it is determined that "NO" has been selected, the image memory is released in step S604, and all the processing ends. Therefore, no image data is sent to the LAN 115.

If it is determined in step S603 that "yes" has been selected, the image data processed in step S601 is transmitted through the LAN 115, and the image transmitted through the LAN 115 is the image shown in FIG. Is the data after the processing indicated by.

(Second Embodiment) In the first embodiment,
In the copy process, a case has been described in which a predetermined image processing process is performed on an input image of a document for which forgery prevention is to be performed. Hereinafter, the embodiment will be described.

FIG. 13 is a characteristic diagram showing the principle of image processing on forged image data in the image processing system according to the present invention.
The horizontal axis indicates the main scanning position of the image. For example, if the image data is M (Magenta), C
(Cyan), Y (Yellow), BK (Blac)
If the color space format is k), the image data has 256 gradations from "0" to "255", and the image becomes darker as it approaches "255".

In FIG. 13, the image data represents the original image before the processing, and is stored in the SDRAM 106 of FIG. If the image data is increased by a certain value for all the pixels of the image data, processed image data is generated. In the image data, all data of “255” or more become “255”, so that information of image change is lost. This processing is performed for M other than Yellow.
An image as shown in FIG. 8B is output by applying the processing to the agents, cyan, and black. Further, as in the case of the first embodiment, it is not possible to return the image after the main processing to the image before the main processing.

If the user decides not to print out the dialog shown in FIG. 10 (when the button BT2 is instructed to be selected), a print stop command is issued and the printing process is completed. .

On the other hand, when the user decides to print the dialog shown in FIG. 10 (button BT)
1 is selected and instructed), the operation history information shown in FIG. 11 is stored in the HDD 108, and the image to be printed is image data after image processing processing is printed out, and the image shown in FIG. The data is not output as it is.

The digital watermark to be used in the present invention may be a digital watermark embedded in a specific frequency in an image that cannot be determined by the naked eye (invisible copy prohibition information), or a size that is inconspicuous on the copy prohibition image. Visible information embedded in color (visible new copy information) or a combination thereof may be used. It is preferable that the pattern is embedded in the pattern of the copy-inhibited image in advance, because the pattern cannot be visually recognized at all.

If the log information of FIG. 11 is encrypted and stored in the folder of the HDD 108 so that it cannot be decrypted unless a dedicated application is used, the history of processing of the copy prohibited image is stored with high security. You can keep.

The log information shown in FIG. 11 may be added as an electronic watermark to the processed image. With this configuration, the added digital watermark can be detected from the printed matter.

(Other Embodiments) In the above embodiment, only an image processing system having a scanner and a printer has been described. However, a system in which a scanner and a printer are connected via a network may be used. Further, an image processing system having only a function of simply generating print data to be supplied to a printer, that is, an image processing system including only the information processing apparatus in the above-described embodiment may be used.

A recording medium storing software program codes for realizing the functions of the above-described embodiments is supplied to a system or apparatus, and a computer (or CPU or MPU) of the system or apparatus is stored in the storage medium. It goes without saying that the object of the present invention is also achieved by reading and executing the program code.

In this case, the program code itself read from the storage medium realizes a novel function of the present invention, and the storage medium storing the program code constitutes the present invention.

Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, an optical disk, a CD-ROM, a CD-R, a DVD, a magnetic tape, a nonvolatile memory card, a ROM, and an EEPROM.
OM or the like can be used.

When the CPU executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the CPU based on the instruction of the program code. ) And the like perform part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into the memory provided in the function expansion board or the expansion function unit inserted into the apparatus, the function expansion board or the function is read based on the program code instruction. It goes without saying that a CPU or the like provided in the extension unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

As described above, according to the present invention,
An image processing system capable of detecting copy-inhibited image data in a short time because it is configured to detect whether or not the image data is image data of a copy-inhibited document by using image data with reduced resolution. It has the effect that it can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of an image processing system according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of image data handled by the image processing system shown in FIG. 1;

FIG. 3 is an explanatory diagram of an image packet format handled by the image processing system shown in FIG. 1;

FIG. 4 is an explanatory diagram of an image packet format handled by the image processing system shown in FIG. 1;

FIG. 5 is an explanatory diagram of a command packet format handled by the image processing system shown in FIG. 1;

FIG. 6 is an explanatory diagram of a command packet format handled by the image processing system shown in FIG. 1;

FIG. 7 is a flowchart showing an entire copy process in the image processing system according to the present invention.

FIG. 8 is a diagram illustrating an example of a forgery prevention processing process in the image processing system according to the present invention.

FIG. 9 is a principle diagram of forgery prevention processing on image data in an RGB color space.

FIG. 10 is a diagram illustrating an example of a warning dialog presented when it is determined that the image is a copy prohibited image.

FIG. 11 is a diagram illustrating an example of log information stored when a copy-prohibited image is detected.

FIG. 12 is a flowchart showing a specific example of a forgery prevention control process in FIG. 7;

FIG. 13 is a principle diagram of forgery prevention processing on image data in the YMCK color space.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B021 AA19 LL01 5B057 AA11 BA02 CA01 CA12 CA16 CB01 CB12 CB16 CC02 CD05 CE08 CG05 CG07 DA07 DA15 DB02 DC33 5C076 AA14 BA06 5C077 LL14 LL18 MP08 PP20 PP23 PP55 SS58 PP65 PP65 PP65

Claims (7)

[Claims] 1. A detecting means for detecting whether or not specific information is included in image data, and a predetermined process is performed on the image data detected by the detecting means to include the specific information. The image data transfer processing in the image processing system is a block unit composed of a predetermined plurality of pixels of the image data, and the detection means An image processing system for performing the detection for each of the block units. 2. The method according to claim 1, wherein the specific information is predetermined image data, and the detection unit performs the detection based on the plurality of blocks of the image data and the predetermined image data. The image processing system according to claim 1. 3. The method according to claim 2, wherein the detecting means includes position detecting means for detecting information on a position including the specific information, and the plurality of blocks to be detected are specified based on the position information. The image processing system according to claim 2. 4. The image processing system according to claim 3, wherein said position detecting means detects the information on the position by using position detecting image data obtained by reducing the resolution of the image data. 5. The image processing system according to claim 1, further comprising an image reading unit that generates the image data. 6. The image processing system according to claim 1, wherein the image data is image data for print output. 7. The image processing system according to claim 6, further comprising image forming means for printing the image data.