JPH07131640A - Device and method for processing image - Google Patents

Abstract

PURPOSE:To reduce the extension of circuit scale required for deciding the plural kinds of images by judging similarity between an input image and a specified image with color space data, which are provided by synthesizing the color space data of plural kinds of original image, as decision data. CONSTITUTION:When the color space of the original image on the front side of a specified original A (such as a 10000-yen bill, for example,) is expressed as 1001, the color space of the original image on the rear side of the specified original A is expressed as 1002 and the color space synthesizing (sum sets) the color spaces of original images on the front and rear sides of the specified original A is expressed as 1003, the color space data 1003 are stored in a ROM for decision. Then, the original images on the front and rear sides of the specified original A are detected by a single deciding circuit by deciding the similarity of color spaces with a color space matching deciding circuit mounting the ROM provided with this data configuration. Therefore, the plural kinds of specified originals A can be decided without extending the circuit scale of the deciding circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus and method for comparing an input color image with a specific image.

[0002]

2. Description of the Related Art In recent years, the reproducibility of read originals has improved with the development of copying machines. Therefore, a technique is required to prevent counterfeiting of bills and the like. As one of the techniques, data of a specific original in a color space is registered in advance, and it is determined whether the distribution of the image data of the input original is almost the same as the data distribution of the specific original in the color space. In this regard, a technique for discriminating a document to be copied has been proposed by the present applicant.

[0003]

However, in the above-mentioned conventional method, for each type of the specific original image,
Since specific documents are detected using different judgment data, if multiple types of specific document images are to be detected, the circuit scale required for the detection should be increased according to the type of specific document. There is a problem that has to be.

The present invention has been made in view of the above problems, and an object thereof is an image processing apparatus and method capable of detecting a plurality of specific document images with a minimum detection circuit scale. Is to provide.

[0005]

In order to achieve the above object, the invention according to claim 1 comprises means for extracting first color space data for a specific image from a plurality of types of specific images, and A synthesizing unit that synthesizes the first color space data to generate the second color space data, a unit that stores the second color space data, and the second color space data that is the determination data of the specific image. And a means for detecting whether or not the input image information includes the image information of the specific image.

According to a fifth aspect of the present invention, a step of extracting the first color space data for the specific image from a plurality of types of specific images, and a step of synthesizing the first color space data to generate a second color space data are combined. Generating the color space data, storing the second color space data, and using the second color space data as the determination data of the specific image, the input image information includes image information of the specific image. And a step of detecting whether or not it is included.

[0007]

With the above construction, a plurality of types of original images are detected by a single determination circuit.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. <Description of Signal Processing Block> FIG. 1 is a block diagram showing a configuration of a signal processing unit of a color image reading apparatus (hereinafter referred to as an apparatus) according to an embodiment of the present invention. In the figure, reference numeral 101 is a CCD color sensor for reading a document image, 102 is an analog amplifier for amplifying an image signal, 103 is an A / D converter, and 104 is brightness according to a reading position of the image signal. Is a shading correction circuit for correcting the dispersion of

Reference numeral 106 denotes read image data,
For example, it is a color space matching determination circuit that calculates in real time the degree of similarity of distribution in a three-dimensional color space with a particular manuscript such as a bill or securities. As described above, by using the color signal after the shading correction, the brightness and tint distortion due to the position of the original is corrected, and the similarity determination in the color space is accurately performed regardless of the position of the input original. Can be done It should be noted that FIG. 12 shows the relationship between the position of a specific document on the document table and the recognition area in this apparatus, and the processing operation of the shading correction circuit 104 in this apparatus is a well-known technique. do not do.

The print signal generation circuit 105 converts the input 8-bit color signals R (red), G (green), and B (blue) into Y (yellow), M (magenta), C (cyan), and This is a circuit for converting into a Bk (black) signal. The print signal generation circuit 105 includes a delay unit for compensating the time required for matching determination described later, and modulates the print signal by the real-time correction signal f (113) from the real-time correction signal generation circuit 107.

The read cycle signal generation circuit 108 includes a read cycle signal HS (109), CLK (110) and VS.
This is a circuit for generating (112). Of these signals,
HS (109) is a main scanning section signal, and CLK (11
0) is the pixel read basic clock signal, and VS
(112) is a section signal indicating an effective area in the sub-scanning direction for reading an original. <Description of Color Space Matching Judgment Circuit> FIG. 2 is a block diagram showing the configuration of the color space matching judgment circuit 106 according to this embodiment. In the figure, the signal R (201) is
It is the upper 5 bits of the R (red) signal 8 bits from the shading correction circuit 104 shown in FIG. Similarly, G (202) is 5-bit G (green)
B (203) is a 5-bit B (blue) signal.

A ROM (read-only memory) 204 stores information relating to the tint of a plurality of types of specific originals, and the R, G, B signals are input to the addresses A _{0 to} A ₁₄ thereof. A determination signal indicating whether or not the input R, G, and B signals match the respective tints of a plurality of types of specific originals is output from the data D _{0 to} D ₇ .

The data stored in the ROM 204 is shown in FIG.
As shown in FIG. 3, it is information regarding the tint of the specific document. When the input signal matches the tint of the specific document, the logic signal 1 is output. When the input signal does not match, the logic signal 0 is output at the data output terminal. It is output from each of D _{0 to} D ₇ . In addition,
Outputs D _{0 to} D ₇ correspond to eight types of specific originals, 0th to 7th.

FIG. 10 is a diagram showing the relationship between the tint data of a plurality of originals stored in the ROM 204 and the bit position of the ROM 204. With this configuration, the determination information regarding the tint of eight different types of specific originals A to H is output in parallel from the output terminals D _{0 to} D _{7 with} respect to the input image data. Further, in FIG. 2, reference numerals 220 to 227 denote tint determination signals X ₀ (210) to X _7.
This is a circuit for performing a smoothing operation described later using the signal of (217). These smoothing circuits 220 to 227 are shown in FIG.
The configuration shown in the block diagram of FIG.

As shown in FIG. 7, each smoothing circuit is composed of multipliers 701 and 702, an adder 703, a latch circuit 704, and a comparator 705. Among them, the multipliers 701 and 702 can perform tint determination considering continuity as shown in FIG. 8 by the weighted average of the input data from the adder 703 and the previous data. That is, as shown in FIG.
In the relationship between the input xi and the smoothed operation value yi, the input xi
If the value of 1 continues, the value of the output yi increases.
From this relationship, when the input R, G, B signals continuously match the tint of the specific document, the smoothed output signals C _{0 to} C
₇ (230 to 237) becomes a logic 1, and more accurate tint determination is possible without being affected by noise or the like.

FIG. 11 is a diagram conceptually showing the determination of the similarity between the distribution of the input color image in the color space and the color distribution of the specific original. The color space determination circuits 240 to 240 shown in FIG.
247 calculates the similarity between the specific image data and the input color signal in the R, G, B color spaces shown in FIG. 11 in real time, and the color space similarity determination signals MK _{0 to} MK ₇ (26
0-267) is calculated.

FIG. 3 shows each color space determination circuit 240-247.
3 is a block diagram showing the internal configuration of FIG. With the circuit configuration shown in the figure, the data Dn from the SRAM 209 of FIG.
The signal Cn from the smoothing circuit is OR-operated, and the result is written in the SRAM 209. Also, the data Dn is 0
Only when the transition from 1 to 1 is made, the content of the counter 301, which is a 10-bit counter, is counted up and cleared at the rising edge of the sub-scanning interval signal VS (112).

Output value Zn of counter 301 and register 3
The constant δn from 03 is compared in magnitude by the comparator 302. If Zn> δn, MKn = 1, Zn
When ≦ δn, MKn = 0. The value of δn is
In FIG. 11, when U _ORG is a numerical value having a unit volume of a cube whose R, G, B coordinate axes are divided into 32, a value of 1% of this U _ORG is set.

That is, δn = (1/100) × U _ORG (1) By the above-mentioned processing, the observed image data, that is, the data of the input color signal string is the specific image data in the R, G, B color space. The color space similarity determination signals MK _{0 to} MK ₇ (260 to 267) are set to logic 1 when the shape becomes substantially the same as the above.

The sectors 271, 272 are for clearing the contents of the SRAM 209 to 0 when the sub-scanning section signal VS (112) is logic 0. The address generator 270 is a circuit that sequentially generates all addresses for the SRAM 209. Specifically, when the sub-scanning section signal VS (112) is logic 0, SR is generated according to the address signal generated by the address generator 270.
AM209 is cleared to 0.

The timing generation circuit 205 is shown in FIGS.
A timing signal as shown in is generated. In FIG. 4, CLK4 (206) is the basic clock CLK (11
0) is a clock signal obtained by dividing the signal by 0, the signal 207 in FIG. 2 is a control signal for the write enable terminal (WE) of the SRAM 209, and the signal 208 is a control signal for the output enable terminal (OE) of the SRAM 209. is there.

FIG. 6 is a block diagram showing the internal structure of the real-time correction signal generation circuit 107 of FIG. With the circuit configuration shown in the figure, the real-time correction signal generation circuit 1
In 07, if it is determined that any one of the plurality of specific document data registered in the ROM 204 matches the observed image data in the color space, the real-time correction signal f
(113) is set to logic one. <Description of Print Signal Generating Circuit> FIG. 13 is a block diagram showing the configuration of the print signal generating circuit 105 according to this embodiment. The masking UCR operation circuit A (6
01) normally generates a print YMCBk signal from an input RGB signal. Further, the masking UCR operation circuit B (602) is a circuit for generating a print YMCBk signal having a different tint (for example, increasing redness) when it is determined that the input color signal matches the specific original.

The selector 603 selects the output signal from the masking UCR operation circuits 601 and 602 by the real-time correction signal f (113) and outputs the selected signal, thereby determining the area determined to match the specific original. Only, a print signal with a color tone different from the original color tone is output. <Explanation of Color Space Composition> FIG. 14 is a view showing the principle of color space composition in this embodiment.

In FIG. 14, the drawing indicated by reference numeral 1001 represents the color space of the original image of the front of the specific original A (for example, 10,000 yen bills), and the reference numeral 1002 indicates the back of the specific original A. 3 represents the color space of the original document image. Reference numeral 1003 represents a color space in which the front and back document images of the specific document A are combined (union).

Therefore, in the apparatus according to this embodiment, the color space data indicated by reference numeral 1003 in FIG. 14 is stored in the ROM for determination 204 having the configuration shown in FIG. Then, the color space matching determination circuit 106 in which the ROM having this data structure is mounted determines the similarity of the color spaces, so that the single determination circuit determines the front and back document images of the specific document A. To detect.

As described above, according to this embodiment,
Like the front and back of a banknote, color data of a plurality of types of original images having similar colors to each other are combined in a color space, and a specific original is determined using the color space data. There is an effect that a plurality of types of specific originals can be determined without increasing the circuit scale. [Modification 1] In the above-described embodiment, when the colors of the images are similar to each other, such as the image on the front side and the image on the back side of the specific document (banknote), the color space data on the front side and the back side are determined for the document determination. Although they are combined and used as the determination data, a modification thereof will be described here.

When the new bill and the old bill of the banknote have similar colors,
For example, if the new bill and the old bill have the same design and the new bill partially uses the fluorescent ink that was not used in the old bill, they are different in the color space of the input color signal. Less is. Therefore, in this modification, as shown in FIG. 15, the image data of the new bill and the old bill are detected by the same determination circuit by combining (union) the color space data of the new bill and the old bill. Is possible. [Modification 2] In the above-described embodiment and modification 1, the determination data is generated by taking the union of two types of color space data. However, in this modification, as shown in FIG. 16, the determination data is generated using only the common part of the two color spaces.

That is, when the color spaces of the two types of image data have a high degree of similarity and the characteristic tint of the original image is present in the common portion, the intersection of the two is obtained as shown in FIG. Determination data is generated from the obtained color space 1601. By doing so as well, it is possible to suppress an increase in the circuit scale of the determination circuit. The present invention is
It may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. Further, the present invention is
It goes without saying that the present invention can also be applied to the case where it is achieved by supplying a program to a system or apparatus.

[0029]

As described above, according to the present invention,
By using the color space data obtained by synthesizing the color space data of a plurality of types of original images as the determination data and determining the similarity between the input image and the specific image, it is possible to increase the circuit scale required for a plurality of types of image determination. Can be reduced.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a signal processing unit of a color image reading device according to an embodiment of the present invention.

FIG. 2 is a color space matching determination circuit 106 according to an embodiment.
It is a block diagram of.

FIG. 3 is a block diagram showing an internal configuration of color space determination circuits 240 to 247.

FIG. 4 is a timing chart showing reading and writing of data in an SRAM 209.

FIG. 5 is a timing chart showing data reading and writing to SRAM 209.

FIG. 6 is a block diagram of a real-time correction signal generation circuit 107.

FIG. 7 is a block diagram showing a circuit configuration of smoothing circuits 220 to 227.

FIG. 8 is a diagram showing a relationship between an input Xi and a smoothed calculation value Yi.

FIG. 9 is a diagram showing a relationship between a shape of a color space of a specific document and a determination ROM 204.

FIG. 10 is a diagram showing a relationship between data and bit positions regarding a plurality of originals stored in a ROM 204.

FIG. 11 is a diagram conceptually showing the determination of the distribution of the input color image in the color space and the similarity of the color distribution of the specific document.

FIG. 12 is a diagram showing the relationship between the position of a specific original on the original table and the recognition area.

FIG. 13 is a block diagram showing a configuration of a print signal generation circuit 105.

FIG. 14 is a diagram showing the principle of color space composition in the embodiment.

FIG. 15 is a diagram showing color space composition in Modification 1;

FIG. 16 is a diagram showing color space composition in Modification 2;

[Explanation of symbols]

 101 CCD color sensor 102 Analog amplifier 103 A / D converter 104 Shading correction circuit 105 Print signal generation circuit 106 Color space matching determination circuit 107 Real-time correction signal generation circuit 108 Reading cycle signal generation circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location 7459-5L G06F 15/70 310 (72) Inventor Masahiro Funada 3-30-2 Shimomaruko, Ota-ku, Tokyo No. Canon Inc.

Claims (5)

[Claims] 1. A means for extracting first color space data for a specific image from a plurality of types of specific images, and a synthesizing means for synthesizing the first color space data to generate second color space data. A means for storing the second color space data, and detecting whether or not the input image information includes the image information of the specific image by using the second color space data as the determination data of the specific image. An image processing apparatus comprising: means for performing. 2. The method according to claim 1, further comprising means for extracting a common portion of the first color space data, wherein the synthesizing means synthesizes the color space data of the common portion.
The image processing device according to item 1. 3. The image processing apparatus according to claim 1, wherein the plurality of types of specific images are images having similar colors. 4. The image processing apparatus according to claim 3, wherein the plurality of types of specific images include front and back images of a banknote. 5. A step of extracting first color space data for a specific image from a plurality of types of specific images, and a step of synthesizing the first color space data to generate second color space data. , Storing the second color space data, and detecting whether or not the input image information includes image information of the specific image by using the second color space data as determination data of the specific image. An image processing method, comprising: