JP2001292298A - Method and device for processing image, method and device for control and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that chronic performance deterioration occurs in print processing since electronic watermark detecting processing is performed even to a general image containing no forgery prevention image as well. SOLUTION: An aspect ratio corresponding to an image is calculated, possibility for the image to be a specified image is decided from the aspect ratio and when it is possible for the image to be the specified image, electronic watermark decision is applied to the image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing method, an image processing apparatus, a control method, an apparatus, and a medium.

[0002]

2. Description of the Related Art In recent years, image reading apparatuses such as scanners,
In the information processing system composed of the host computer and the color output device, an electronic watermark detection process, which is attracting attention as a countermeasure against counterfeit bill printing such as outputting a bill image illegally read by a scanner by a color printer, Addition to printing processing from a host computer to a color output device is being considered.

[0003]

However, the above technique has the following problems. Since the electronic watermark detection process is performed also on a general image that does not include a forgery prevention image, there is a problem that chronic performance degradation of the print process is caused.

[0004] The present invention has been made in view of the above conventional example.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention calculates an aspect ratio according to an image, determines whether the image may be a specific image from the aspect ratio, and determines whether the image is a specific image. When there is a possibility of an image, a digital watermark determination is performed on the image.

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[First Embodiment] <System Configuration> FIG. 1 shows an example of an image input and image output system configuration according to an embodiment of the present invention, which is used for an illegal counterfeit bill printing operation. Image input
It is also an example of an output system. Image input device iid such as scanner and color image output device i such as color printer
od is connected to the host computer hc. still,
In FIG. 1, the image input device iid and the image output device iod are different devices, but may be an image output device having an image input function. The connection form of each device in FIG. 1 includes not only a local connection but also a connection via a network. Further, the host computer that captures an image by the image input device and the host computer that outputs an image to the image output device need not be the same host computer.

<Control Flow for Preventing Counterfeit Banknote Output> FIG.
It is a figure which shows the outline | summary of the counterfeit banknote output prevention control flow in a present Example. In the application 201 installed in the host computer hc in FIG. 2, an input is performed directly or indirectly from an image input device (not shown). The indirect input is a case where an image input from an image input device is directly performed in a host computer different from the host computer in FIG. 2 and then the image file is transferred to the host computer hc in FIG. is there. When the system user gives an instruction to print an image file, image data is passed from the application 201 to the printer driver 203 via the graphic engine 202. In the printer driver 203, in the printer driver module / data unit 204, the print data is converted to data (PDL
The characteristic is that in the processing of the printer driver module / data section 204, the fake bill image primary check module 205 is called, and whether the fake bill image read by the image input device is included in the print data. Is checked, and the electronic watermark detection module 206 is called only when it is determined that counterfeit banknotes are included. Since the digital watermark detection process lowers the performance of the print process of the printer driver, the digital watermark detection process is not always executed, but is performed.
By performing a primary check of a counterfeit banknote image as a pre-process, reduction in performance in print processing of general print data that does not include a counterfeit banknote image is attempted. The counterfeit banknote image primary check module 205
Table 2 storing information on various banknotes to be forged
07 is read. If the forged banknote image primary check module 205 determines that the forged banknote image is not included and the electronic watermark detection module 206 determines that the forged banknote image is not a forged banknote image, the pre-writer driver 203 sends the system via the system spooler 208 to However, when the electronic watermark detection module 206 determines that the banknote is a counterfeit banknote, the output process is stopped. Hereinafter, the internal processing of the counterfeit banknote image primary check module will be described with reference to FIGS.

The digital watermark to be detected in the present embodiment may be either one embedded in the image as visible information or one embedded in the spatial frequency region of the image as invisible information, and is not limited to the type of electronic watermark.

FIG. 3 is a diagram showing an outline of a forged banknote image primary check processing flow. The process in FIG. 3 is realized by the CPU of the host computer performing a software operation by the printer driver.

In step 301, the output data passed through the graphic engine 202 shown in FIG. 2 includes a shadow around the image to be scanned caused by a height difference between the platen of the image input device (scanner) and the surface of the object to be scanned. Then, the process proceeds to step 302 after performing the detection processing of the margin area that does not include the characters and the images existing on the four sides of the forgery prevention image.

In step 302, the result of the detection processing performed in step 301 is determined. If it is determined that the forgery prevention image area is detected, the process proceeds to step 30.
The process proceeds to the scan target image extraction process of No. 3, but if the forgery prevention image region is not specified, the process proceeds to the output execution process of step 309 to avoid the electronic watermark detection process.

In step 303, the image area of the object to be scanned placed on the platen of the image input device (scanner) is determined based on the position information of the area detected by the forgery prevention image area detection processing in step 301. If it is determined that the image area of the object to be scanned is rectangular, the image area is extracted.

In step 304, the result of the process for extracting the image to be scanned in step 303 is determined. Here, if it is determined that the rectangular image area has been extracted, the process proceeds to the aspect ratio calculation / verification processing in step 305. If it is determined that the rectangular image area has not been extracted, step 30 is performed.
Then, the process proceeds to the output execution process 9 to avoid the digital watermark detection process.

In step 305, the aspect ratio is calculated for the rectangular image area of the scan target object extracted in the scan target image extraction process in step 303, and various forgery stored in the forgery prevention bill information table 207 of FIG. A search is performed to determine whether there is a suitable or approximate value in the aspect ratio information table of the image to be prevented, and the process proceeds to step 306.

In step 306, if it is determined that the output data contains a forgery prevention image based on the verification result of the aspect ratio calculation / verification processing in step 305, it is extracted in the scan target image extraction processing in step 303. In order to execute the electronic watermark information detection processing for the rectangular image area, the process proceeds to the electronic watermark detection processing in step 307. If it is determined that the output data does not include the forgery prevention image, the processing proceeds to step 309. The process proceeds to the output execution process to avoid the electronic watermark detection process.

In step 307, a process of detecting digital watermark information embedded in the forgery prevention image is performed.
It should be noted that the electronic watermark information is invisible information embedded in each forgery prevention image, and the method of detecting the information is also different depending on the applied electronic watermark embedding technology.

In step 308, the result of the electronic watermark detection processing in step 307 is determined. If the digital watermark information is detected and it is determined that the image is a forgery prevention image, the process proceeds to step 310, and the output process to the printer is stopped. If no electronic watermark information is detected,
The process proceeds to the output execution process of step 309.

The above is the outline of the control flow of this implementation example. Details of each step will be described below.

<Scan Shading Detection> FIG. 4 (upper part) schematically shows a flatbed scanner. In a flatbed scanner, the scanning object S
The front side of t is set to face the original glass table Fb. The reading of an image is started after a pressure plate (plate for holding a document) (not shown) is closed. Since the surface of the platen on the side of the platen glass is white, as a result of reading the scan target St from below the platen glass, the background of the scan target becomes the white color of the platen.

FIG. 4 (lower part) is a schematic view showing a state in which the scan target set on the original glass table is viewed from the side. As shown in the drawing, a height difference Δh occurs between the surface of the document table Fb and the surface of the scan target St. Due to the height difference Δh, a shadow (FIG. 5) is generated around the scan target in the image of the scan result. In the present embodiment, a scan shadow indicating that the data has been read by the scanner is detected from the output data passed into the driver.

Hereinafter, an example of a method for detecting a scan shadow will be described with reference to FIG.

FIG. 6 shows an image of a general scan result. The area surrounded by the dotted line includes the background of the scan target (hereinafter, area 1) and the shaded area of scan (hereinafter, area 1) from the left.
Area 2), an image of a bill to be scanned (hereinafter referred to as a bill)
Area 3) is included. First, a change in luminance information at each pixel is checked from the left end of a certain line of image data included in the output data to the right.
In area 1 of FIG. 6, substantially uniform luminance values are shown. The luminance decreases in the area 2 and increases again in the area 3 so that the marginal area around the image shows a substantially uniform luminance value. Check this brightness value on several lines,
The position where the luminance value changes is determined. In the same manner, the upper side, the lower side, and the right side of the scan shadow are detected. When the position where the luminance value changes is not constant or the four sides of the scan shadow are not detected by the above method, the process proceeds to the forgery prevention image margin detection process described below. If all of the four sides of the scan shadow have been detected (up, down, left, and right), the process proceeds to the next process of extracting a scan target image.

<Detection of Forgery Prevention Image Margin> There may be a case where a suitable printed matter is intentionally inserted between the scan target St and a pressure plate (not shown) in FIG. 4 to make the background of the scan target an arbitrary image. . This act is known as a means of circumventing the forgery prevention device by interleaving the forgery prevention image into an arbitrary image. In such a case, it is difficult to specify the scan shadow in the scan shadow detection processing described above. Therefore, detection processing of a forgery prevention image, that is, a margin (margin) area existing on four sides of a bill is performed as correspondence to confusion information based on an arbitrary background.

Hereinafter, an example of a method of detecting a forgery prevention image margin will be described with reference to FIG.

The portions surrounded by the dotted lines in FIG. 7 include, from the left, the background of the object to be scanned (hereinafter, area 1), the shaded portion of the scan (hereinafter, area 2), the margin of the bill to be scanned (hereinafter, area). 3), an image of a bill to be scanned (hereinafter, area 4) is included. First, a change in luminance information at each pixel is checked from the left end of a certain line of image data included in the output data to the right. At this time, the following conditions are set to specify the area 3 in FIG. 7, that is, the margin area of the bill.
-The width (fw) of the non-white, almost uniform luminance area is:
It must be continuous over a specific width (mMin). The specific width (mMin) is the forgery prevention bill information table 20 in FIG.
7 indicates the minimum value in the margin information of the various types of forgery prevention target images. However, a certain amount of tolerance is given in consideration of an error (Δm) due to a shift or distortion during image reading.

Fw ≧ mMin−Δm

In the same manner, the upper, lower and right sides of the forgery prevention image margin are detected. In the above way,
If the four sides of the forgery prevention image margin are not detected, the output is executed without performing the electronic watermark detection process. If all four sides of the forgery prevention image margin have been detected (up, down, left, and right), the process proceeds to the scan target image extraction process in the next step.

<Extraction of Scan Target Image> The image area of the scan target is obtained based on the position information of the scan shadow obtained in the scan shadow detection processing in the previous process or the position information of the margin area obtained in the forgery prevention image margin detection processing. To determine. At this time, it is checked whether or not the determined image area of the scan target is a rectangular area, like general banknotes and securities. However, since a completely rectangular shape cannot be expected due to the nature of the scanned image, the determination is made with some allowance. If the image area of the scan target is determined to be a rectangle, only the image area is extracted and used in subsequent processing. On the other hand, when it is determined that the image area of the scan target is not rectangular, the output is executed without performing the electronic watermark detection process.

<Calculation of Aspect Ratio> FIG. 8 shows an outline of an aspect ratio calculation processing flow. In step 801,
After storing the height of the scan target image extracted in the scan target image extraction process in the variable h and the width in the variable w, the aspect ratio A is obtained by the following calculation.

A = h / w

In step 802, it is determined whether the value of the aspect ratio A is greater than 0 in consideration of the direction in which the scan target is set on the document table. Since general banknotes have a horizontal size larger than a vertical size, if the direction of the scan target set on the platen of the scanner device is horizontal, the calculation result of the above formula is 0 or less, and in this case, Goes to step 803. When the direction of the scan target set on the platen of the scanner device is vertically long, the calculation result of the above expression becomes 0 or more. In this case, the present process ends, and the process proceeds to the subsequent aspect ratio verification process. .

In step 803, the aspect ratio A is recalculated from the following calculation based on the determination result in step 802.

A = w / h

By the processing in this step, the aspect ratio A
Is unified to a value larger than 0, that is, a value indicating how many times the long side of the rectangle is the short side. Step 802
The aspect ratio of the image to be scanned calculated in step (1) is used in the aspect ratio verification processing in the subsequent stage.

<Aspect Ratio Verification> FIG. 9 is a schematic diagram of the aspect ratio verification processing flow. In step 901,
Initialization processing is performed such as setting the number of registration information in the forgery prevention bill information table to max, and initializing the aspect ratio verification result flag ret.

In step 902, the aspect ratio of the image to be scanned obtained in the aspect ratio calculation process of the preceding stage is compared with the aspect ratio information of the entry idx in the forgery prevention bill information table.

In step 903, the result of step 902 is determined. If the banknote having the same or similar aspect ratio as the image to be scanned is the entry idx in the forgery prevention banknote information table, the flow advances to step 904 to change the aspect ratio. The process is terminated by setting TRUE to the verification result flag ret, and the process proceeds to the subsequent stage of the digital watermarking process transition determination process.

On the other hand, if it is determined in step 903 that the aspect ratio of the scan target image and the entry idx in the forgery prevention bill information table are completely different, step 9
Proceed to 05.

In step 905, 1 is added to the value of idx so that the target to be compared with the aspect ratio of the image to be scanned is the next entry in the forgery prevention bill information table. In step 906, it is checked whether or not the value of idx exceeds the number of registered entries in the forgery prevention banknote information table. If the value exceeds max, the process ends with the aspect ratio verification result flag ret set to FALSE. The processing shifts to electronic watermark processing shift determination processing.

On the other hand, if the value of idx does not exceed max, the process returns to step 902 to compare with the aspect ratio information stored in the idx-th entry of the forgery prevention bill information table.

<Forgery Prevention Banknote Information Table> FIG.
It is the figure showing an example of the storage information of a forgery prevention bill information table. As shown in the figure, the anti-counterfeit banknote information table stores information on various types of banknotes in each country, and each includes a country identification ID for identifying a country, a currency indicating a monetary unit such as '￥', etc. A field for setting a unit ID, a banknote notation value representing a banknote value written on the banknote, and an aspect ratio to be referenced and compared in the above-described aspect ratio verification processing is defined. Although not shown in the figure, information on margin areas (margins) on the four sides of the bill is stored and referred to in the forgery prevention image margin detection processing. The forgery prevention bill information table has the printer driver of FIG. 2 built therein or exists as an external file, and stores information on bills of each country in advance. The forgery prevention bill information table is not fixed information, and also allows new addition and deletion of bills.

<Digital Watermark Processing Determination> The result of the aspect ratio verification processing in the preceding stage is determined, and it is determined whether or not to perform digital watermark detection processing on the image area extracted in the scan target image extraction processing. If it is determined by the aspect ratio verification process that a counterfeit banknote image may be included, the process proceeds to a digital watermark detection process. On the other hand, when it is determined that the forged bill image is not included, the output is executed.

If the output document data covers a plurality of pages, it is checked whether or not each page data contains a forgery-prevention bill image. Execute the output. Alternatively, it may be determined whether or not to output the entire output document data after checking whether or not a forged bill image is included in the entire output document.

As described above, the performance of the printing process is one of the precedent processes of the electronic watermark detection process which is noticed as a preventive measure against counterfeit bill printing such as outputting a bill image illegally read by a scanner by a color printer. Whether it is necessary to perform a digital watermark detection process that degrades the image (whether a suspicious image is included) or general image data that does not require the digital watermark detection process, based on the aspect ratio information of the image By making the determination, there is an effect that the performance degradation accompanying the forgery prevention output processing is reduced.

[Other Embodiments] The present invention relates to a plurality of devices (for example, a host computer, an interface device,
Even if applied to a system composed of readers, printers, etc., devices consisting of one device (copier, printer,
Facsimile machine, etc.).

An object of the present invention is to provide a computer-readable storage medium storing software program codes for realizing the functions of the above-described embodiments by a computer (or CPU or MPU) of a system or apparatus. It is also achieved by reading and executing the code.

In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

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, RO
M or the like can be used.

When the computer 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 computer based on the instruction of the program code. ) Performs 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 in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the program code is read based on the instruction of the program code. The CPU included in the function expansion board or the function expansion unit may perform part or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

[0052]

As described above, according to the present invention, an aspect ratio according to an image is calculated, and from the aspect, it is determined whether or not the image is a specific image. In some cases, since the digital watermark determination is performed on the image, the digital watermark determination that is heavy in processing (the performance is significantly deteriorated) can be limited to only those having a high possibility of the specific image, and the performance can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of an image input / output system that is misused for a counterfeit bill printing operation.

FIG. 2 is a diagram showing an outline of a counterfeit bill output prevention control flow.

FIG. 3 is a diagram showing an outline of a forged banknote image primary check processing flow.

FIG. 4 is a schematic diagram of a scanner device.

FIG. 5 is a schematic diagram of a shadow around an image to be scanned.

FIG. 6 is a schematic diagram of a scan shadow detection process.

FIG. 7 is an outline of a forgery prevention image margin detection process.

FIG. 8 is a schematic diagram of an aspect ratio calculation processing flow.

FIG. 9 is a schematic diagram of an aspect ratio verification processing flow.

FIG. 10 is a diagram showing storage information of a forgery prevention bill information table.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/40 H04N 1/40 Z 5C077 9A001 F term (Reference) 2C061 AP04 AP07 AR01 CL10 2C087 AA15 AB05 BB10 BD01 BD24 CB02 DA07 DA11 DA13 2H034 FA01 5B057 AA11 CA12 CA16 CB12 CB16 DA01 DB02 DC30 5C076 AA01 AA14 BA06 5C077 LL14 MP08 NP07 PP23 PP60 PP65 PP66 SS01 SS06 TT02 9A001 HH23 JJ35 LL03

Claims (19)

[Claims] 1. An aspect ratio according to an image is calculated. From the aspect ratio, it is determined whether or not the image has a possibility of a specific image. An image processing method comprising performing a digital watermark determination. 2. The image processing method according to claim 1, wherein the image is read by a reading device. 3. The image processing method according to claim 1, wherein a specific image area candidate is determined for the image read by the reading device by detecting a shadow or detecting a margin. 4. The image processing method according to claim 3, wherein, if the area determined by the shadow or the margin detection result is substantially rectangular, the specific image area candidate is used. 5. The image processing method according to claim 3, wherein the aspect ratio is calculated for the specific image area candidate in the image. 6. The image processing method according to claim 1, wherein the determination of the specific image is realized by software processing. 7. The image processing method according to claim 5, wherein the calculation of the aspect ratio and the determination of the digital watermark are not performed when there is no specific image area candidate. 8. The method according to claim 1, wherein as a result of the digital watermark determination, if it is determined that the image is the specific image, at least one of printing prohibition, abnormal printing, and warning display is performed. Image processing method. 9. An image processing apparatus for performing the image processing method according to claim 1. 10. A storage medium storing a code for performing the image processing method according to claim 1. Description: 11. An apparatus comprising an image reading device such as a scanner, an information processing device such as a personal computer, and a color image output device such as a color printer, wherein bills and securities read from the image reading device into the information processing device. For a forgery prevention target image, etc., a control method for preventing the output action to the color image output device, detecting a shadow around the scan target image included in the scan image read from the image reading device,
Detecting a margin of the forgery prevention image included in the scan image read from the image reading device, and extracting only the scan target image from the scan target image area information detected by the scan shadow detection or the forgery prevention image margin detection; Calculating the aspect ratio of the extracted scan target image, verifying the similarity between the calculated aspect ratio information of the scan target image and the aspect information of the forgery prevention target image, and according to the verification result. And determining whether to execute a process of detecting electronic watermark information included in the forgery prevention image. 12. The scan shadow detection means that a shadow around a scan target image caused by a height difference between a platen of the image reading device and a surface of the scan target object is output to the color image output device. The control method according to claim 1, wherein the detection is performed from an image. 13. The forgery-prevention image margin detection includes:
The control method according to claim 1, wherein, when the scan shadow is not detected, a margin area that does not include characters or images existing on four sides of the forgery prevention image is detected. 14. The scanning target image extraction means that the scanning target image is output to the color image output device based on the scanning target image area information detected by the scan shadow detection or the forgery prevention image margin detection. Determining an image area of the scan target placed on the platen of the image reading apparatus from the image data, and extracting the image area when it is determined that the image area of the scan target is rectangular. Item 2. The control method according to Item 1. 15. The method according to claim 1, wherein calculating the aspect ratio includes calculating an aspect ratio of a rectangular image area of the scan target in the image reading device, which is extracted in the scan target image extraction. The control method described. 16. In the aspect ratio verification, a search is performed from an aspect ratio information table of a forgery prevention target image for the aspect ratio information regarding the rectangular image area of the scan target calculated by the aspect ratio calculation, and the same search is performed. The control method according to claim 1, wherein the presence or absence of approximate aspect ratio information is verified. 17. The electronic watermark processing shift determination means that the image to be output to the color image output apparatus may include a forgery prevention image based on the verification result of the aspect ratio verification. If it is determined, it is determined that the electronic watermark information detection process is to be performed on the image region extracted in the scan target image extraction, and the forgery prevention image is not included in the output target image to the color image output device. 2. The control method according to claim 1, wherein when it is determined that the electronic watermark information is not detected in the image area extracted in the scan target image extraction. 18. A control device for performing the control method according to claim 11. 19. A storage medium storing a code for performing the control method according to claim 11. Description: