JPH0662235A - Special original discriminating device - Google Patents

Abstract

PURPOSE:To improve accuracy for judging paper money by calculating the length of a base edge in a base area approximated to the base level of the paper money, calculating the centroid of the base edge when this length is coincident with previously stored data, and comparing a previously registered pattern with image data by using this centroid. CONSTITUTION:A forgery proof unit 104 constituting an image forming device is composed of a base edge detection part 105 to detect the base edge of the base area approximated to the base level of the paper money, base edge length data storage part 106 to store the data of the base edge length peculiar for the paper money, base edge length judge part 107 to measure the length of the detected base edge, to compare the length with the data stored in the storage part 106 and to judge whether they are coincident or not, position detection part 108 to detect the centroid position of the edge when this judged result is coincider with each other, storage part 109 to register the feature pattern of the paper money used for deciding similarity as the centroid position, and discrimination processing part 110 to compare and discriminate the pattern and the image data. When operating these parts, respective scanner, image and printer units 101, 102 and 103 are used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a special document discriminating apparatus used for preventing forgery of a digital copying machine or the like, and a special document discriminating device for detecting the position of a bill in a document and thereafter discriminating whether it is a bill or not. The present invention relates to a document discriminating apparatus.

[0002]

2. Description of the Related Art In recent years, due to improvements in image processing technology and image forming technology, it has become possible to perform image formation so finely that copy bills copied by a color copying machine and actual bills cannot be easily distinguished. For this reason, there has been developed an apparatus that discriminates special documents such as banknotes and prohibits the copying operation in the case of special documents.

As a device used for preventing forgery of a special document, for example, as disclosed in Japanese Patent Application Laid-Open No. 2-210591, "Image Processing Device", the position state of the document is detected and an image of a specific portion in the document is detected. An apparatus has been developed that identifies a special document by taking out data and determining the degree of similarity with a pattern registered in advance.

[0004]

However, according to the "image processing apparatus" of Japanese Patent Laid-Open No. 2-210591, the position and angle of the banknote are calculated by detecting the four corners of the banknote. In the case of a manuscript in which banknotes are closely arranged without gaps, the four corners of the banknote are undetectable, the positions where the banknotes are placed cannot be obtained, and the banknotes cannot be determined.

The present invention has been made in view of the above, and an object of the present invention is to reliably detect the position where a bill is placed and to improve the accuracy of bill determination.

[0006]

In order to achieve the above object, the present invention is a special document discriminating apparatus for discriminating whether or not the content of input image data is a bill, and the length of the background edge peculiar to the bill. Edge length storage means that stores data, a background edge detection means that detects a background edge of a background area that is similar to the background level of a banknote, and a length of the background edge detected by the background edge detection means is measured. A background edge length determining means for comparing with the data in the edge length storing means to determine whether or not they match, and a position detecting means for detecting a specific position of the background edge when the results of the background edge length determining means match. A special document discriminating apparatus provided with a discriminating means for discriminating whether a banknote is a banknote by comparing a pattern registered in advance at a specific position with image data.

[0007]

In the special document discriminating apparatus of the present invention, first, the length of the background edge of the background area approximated to the background level of the banknote is calculated, and the length of the background edge is stored in advance. If the length is the same as the length, the center of gravity (specific position) of the background edge is calculated, and the pattern registered in advance at the specific position is compared with the image data to determine whether it is a bill.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image forming apparatus to which the special document discriminating apparatus of the present invention is applied will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram of the image forming apparatus of this embodiment, in which a scanner unit 10 for reading a document is used.
1, an image data read by the scanner unit 101 is input, and an image processing unit 102 that performs shading correction processing, γ correction processing, gradation processing, and the like, and image data that has been subjected to image processing by the image processing unit 102 are output. The printer unit 103 and the forgery prevention unit 104 (special document discriminating device of the present invention) for inputting image data through the image processing unit 102 and determining whether the document is a banknote.

The forgery prevention unit 104, as shown in the figure,
A background edge detection unit 105 that detects a background edge of a background area that is close to the background level of a banknote, and a background edge length storage unit 106 that stores background edge length data specific to a banknote.
And a background edge length determination unit 107 that measures the length of the background edge detected by the background edge detection unit 105 and compares the data with the data stored in the background edge length storage unit 106 to determine whether or not they match. When the determination results of the background edge length determination unit 107 are the same, a position detection unit 108 that detects a specific position of the background edge, and a storage unit 109 that previously registers the characteristic pattern of the banknote used for similarity determination at the specific position, A discrimination processing unit 110 that compares a pattern registered in advance at a specific position with image data and discriminates whether or not it is a bill is provided.

The operation of the above configuration will be described. The image data read by the scanner unit 101 is subjected to image processing such as shading correction processing, γ correction processing and gradation processing by the image processing unit 102, and then copied on recording paper by the printer unit 103.
On the other hand, the image data read by the scanner unit 101 is sent to the forgery prevention unit 104 at the same time and the determination for the forgery prevention is executed.

FIG. 2 is a flow chart showing the processing in the forgery prevention unit 104. When the image data is input from the scanner unit 101, the forgery prevention unit 104 first detects the background edge of the background area close to the background level of the bill in the background edge detection unit 105 (S201). Here, the background level data of the banknotes consisting of R, G, and B is the background edge detection unit 10 in advance.
5 is stored. Further, as shown in FIG. 1, the image data from the scanner unit 101 is simultaneously sent to the discrimination processing unit 110.

The background edge data detected by the background edge detecting section 105 is sent to the background edge length determining section 107 and the position detecting section 108. In the background edge length determination unit 107,
The length of the background edge detected by the background edge detection unit 105 is measured, compared with the data stored in the background edge length storage unit 106 to determine whether or not they match, and the determination result is output to the position detection unit 108. Yes (S202).

If the judgment result of the background edge length judging unit 107 is coincident, the position detecting unit 108 judges the background edge detecting unit 10
The center of gravity (specific position) of the background edge is detected using the background edge data detected in step 5 (S203). Specifically, as shown in FIG. 3, the pixels of the background edge (hereinafter referred to as edge pixels) are numbered, and the x and y coordinates of the i-th edge pixel are defined as (x _i , y _i ) respectively. Then, the coordinates (bar x, bar y) of the center of gravity of the edge pixel are obtained by the equations (1) and (2) shown in Equation 1. However, i is 1 to N, and N is the total number of edge pixels.

[0015]

[Equation 1]

The discrimination processing unit 110 compares the pattern registered in advance with the coordinates of the center of gravity of the edge pixel and the image data to discriminate whether or not it is a bill (S204). Output a stop signal (S205, S20
6), the process ends. On the other hand, if it is not a bill, a copy continuation signal is output (S205, S207), and the process ends.

By carrying out such processing, it is possible to reliably determine the position where the bill is placed on the original image. Therefore, the accuracy of the bill discriminating process is improved by reliably performing the position determination as the preprocessing for discriminating the bill.

[0018]

As described above, the special document discriminating apparatus of the present invention is a special document discriminating apparatus for discriminating whether the content of the input image data is a bill or not. The background edge length storage means for storing the background edges, the background edge detection means for detecting the background edges in the background area approximate to the background level of the banknote, and the background edge length detected by the background edge detection means are measured to obtain the background edge length. A background edge length determining unit that compares the data with the data in the storage unit to determine whether they match, and a position detecting unit that detects a specific position of the background edge when the results of the background edge length determining unit match, and a specific position Since it is provided with a discriminating means for discriminating whether or not it is a bill by comparing the pattern data registered in advance with the image data, the position where the bill is placed is surely detected,
It is possible to improve the accuracy of bill determination.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of an image forming apparatus to which a special document determining apparatus according to the present exemplary embodiment is applied.

FIG. 2 is a flowchart showing a process of a forgery prevention unit.

FIG. 3 is an explanatory diagram showing calculation of coordinates (specific position) of the center of gravity of an edge pixel in a position detection unit.

[Explanation of symbols]

 Reference Signs List 101 scanner unit 102 image unit 103 printer unit 104 forgery prevention unit 105 background edge detection unit 106 background edge length storage unit 107 background edge length determination unit 108 position detection unit 109 storage unit 110 determination processing unit

Claims (1)

[Claims] 1. A special document discriminating apparatus for discriminating whether or not the content of input image data is a bill, and a background edge length storage means for storing length data of a background edge peculiar to a bill, and a background level of the bill. The background edge detecting means for detecting the background edge of the background area approximated by the above, and the length of the background edge detected by the background edge detecting means are measured and compared with the data of the background edge length storing means to determine whether they match. If the determination result of the background edge length determining means and the determination result of the background edge length determining means are the same, the position detecting means for detecting a specific position of the background edge, the pattern previously registered at the specific position, and the image A special document discriminating apparatus comprising: discriminating means for discriminating whether or not a bill is compared with data.