KR101014974B1 - Apparatus and method for recognizing an image of paper money - Google Patents

Abstract

The present invention is to obtain a uniform bill image through the correction in consideration of the CIS value of the imaging means by the LED characteristic of the light emitting means, as the LED characteristic is reduced output efficiency based on time and / or temperature, bill image In order to compensate for the deterioration of the recognition quality of the CIS, the amount of CIS transmission by a predetermined white medium is checked, and after adjusting the CIS output gain GAIN, the banknote is transferred to obtain a corrected image output value, or the CIS by the white medium. By obtaining the corrected image output value by multiplying each parameter value set by the transmission amount by the image output value of the CIS, it is possible to obtain a uniform bill image.

       Bills, recognition, LED, transmittance, gain, parameters

Description

Apparatus and method for recognizing an image of paper money}

1 is a flow chart showing a conventional banknote image acquisition method

Figure 2a is a graph showing that the sharpness of the output image is degraded according to the LED temperature.

2B is an exemplary diagram showing that the sharpness of the output banknote image is degraded as the temperature in FIG. 2A is increased.

3 is a block diagram showing the configuration of the banknote identifier of the present invention.

Figure 4 is a view showing a configuration in which the bill is transferred and the image is obtained in the present invention

5a-5e illustrate a process of checking the CIS permeation amount before entering a banknote

6a and 6b are views showing the image output through the control of the gain (Gain) of the CIS based on the result of confirming the transmission amount of the white medium portion;

7A-7C are diagrams for checking the amount of CIS transmission after entering banknotes.

8A and 8B illustrate embodiments in which an output image is adjusted by multiplying a parameter based on a transmission amount.

9 is a schematic flowchart of the present invention showing a banknote image output correction by the CIS transmission amount.

10 is a flowchart showing the amount of transmission of the image sensor before entering banknotes

11 is a flow chart showing the amount of transmission of the image sensor after entering banknotes

The present invention relates to an image recognition apparatus and method for obtaining a uniform bill image value, and controlling the output value of the bill recognition module to a predetermined value in consideration of the characteristics of the bill recognition module.

Hereinafter, related art according to the present invention will be described.

1 is a flowchart 100 of a conventional banknote image acquisition method.

Acquire images (videos) including bills. (S 101).

The acquired image is processed (processed). (S 103).

The bill is recognized based on the processed image. (S 105).

The prior art as described above obtains an image, and if the image quality is poor, a desired image is obtained through a normalization process through image processing.

On the other hand, in the conventional banknote image acquisition, the light emitting means (LED), although the performance is reduced based on the temperature or use time, etc., there was no additional measures for correcting the output value.

Figure 2a is a graph showing that the sharpness of the output image is degraded according to the LED temperature. FIG. 2B is an exemplary diagram showing that the sharpness of the output banknote image deteriorates as the temperature in FIG. 2A increases. As shown in Figure 2b it can be seen that the sharpness is lowered sequentially as the temperature increases.

In other words, the related art is a method of acquiring and recognizing an image regardless of a characteristic change of a CIS LED. This technology does not perform any control even though the LED brightness changes according to temperature and time characteristics when the LED is continuously turned on, so the amount of image transmission to the banknote is small in the transparent image sensor. Stripes occur in the background.

The present invention aims to obtain a uniform image without being influenced by the temperature and time characteristics of the CIS and / or LED.

In addition, an object of the present invention is to adjust the quality of the input image by searching for the brightness of the light passing through the white medium attached to the LED.

In addition, the present invention is to perform the bill recognition in consideration of the LED (Light Emitting Diode) characteristics of the light emitting means, and the CIS (Contact Image Sensor) value of the imaging means included in the banknote recognition module, in particular LED characteristics are time and / or As the output efficiency decreases based on temperature, in order to compensate for the degradation of the recognition quality of the banknote image, the amount of LED transmission in the CIS (hereinafter referred to as CIS transmission) by the predetermined white medium or the amount of transmission in the CIS through the medium (hereinafter CIS) Check), 1) adjust the CIS output gain (GAIN), which is one of the predetermined values, and transfer the bills to obtain a corrected image output value, or 2) the CIS transmission amount as another one of the predetermined values. By obtaining a corrected image output value by multiplying the parameter value set by the image output value of the CIS, an object of a uniform bill is obtained.

In order to achieve the above object, a bill image recognition apparatus according to the present invention comprises: an image sensor; Light emitting means for emitting light to the image sensor; A memory unit in which at least one reference value of a transmission amount of an image sensor or a parameter value set in consideration of the transmission amount value is stored in contact with the light emitting means and formed in a portion of the light emitting means that is not a bill transfer path; And a controller configured to reflect the gain according to the reference value or to control at least one application of the parameter value to correct the banknote image output value.

In addition, the banknote image recognition method according to the present invention, the step of attaching a predetermined medium;

Confirming a transmission amount of the image sensor through the medium; Comparing the obtained transmission amount with a predetermined reference value; And reflecting a gain value in the image sensor based on the comparison result.

In addition, the banknote image recognition method according to the present invention, the step of attaching a predetermined medium; Setting a parameter in consideration of the amount of transmission of the image sensor through the medium; Confirming a transmission amount of the image sensor through the medium; And correcting the banknote image output value by applying the set parameter based on the confirmed transmission amount.

Hereinafter, with reference to the drawings will be described in more detail with respect to the banknote image recognition apparatus and method according to the present invention.

First, the term mentioned in the present invention, for example, the banknote recognition module includes each component of FIG. 3. CIS and LED, which are mentioned to recognize banknotes in the present invention, are one example and may be replaced by other means, such as CCD or OLED, etc., as well as means that are now apparent to those skilled in the art.

In addition, the terminology used in the present invention is a general term used as widely as possible at present, but in certain cases, the term is arbitrarily selected by the applicant, which is described in detail in the description of the corresponding invention, the meaning of simple terms It is to be understood that the present invention should be understood as the operation / meaning of terms rather than names. For example, it is understood that the CIS transmission amount represents the amount of LED transmission in the CIS by the predetermined medium or the amount of transmission in the CIS through the medium, respectively.

An overview of the present invention is as follows.

Specifically, the present invention intends to perform banknote recognition in consideration of the LED (Light Emitting Device) characteristics of the light emitting means and the CIS (Contact Image Sensor) value of the imaging means included in the banknote recognition module, the LED characteristics are time and And / or the amount of LED transmission in the CIS by a white medium or the amount of transmission in the CIS through the medium (hereinafter referred to as CIS transmission) Check), 1) adjust the CIS output gain (GAIN), which is one of the predetermined values, and transfer the bills to obtain the corrected image output value, or 2) the other one of the predetermined values to the CIS transmission amount. By obtaining the corrected image output value by multiplying the parameter value set by the image output value of the CIS, a uniform banknote image can be obtained. Corrections by 1) and 2) may be performed simultaneously or simultaneously.

The output image correction by the CIS gain adjustment is generally controlled before the bill is transferred, and the control by the parameter value has been described as being used to correct the output image while the bill is transported. VICE VERSA) or a mixture can be applied. In addition, the control by the gain adjustment can be easily applied by applying the gain (-1, +1) according to the large and small CIS transmission amount based on a predetermined reference value, and apply the parameter value differently in each step of each CIS transmission amount. By doing so, the output image can be corrected effectively.

In one embodiment of the correction of the banknote image output value by checking the CIS transmission amount, a predetermined portion of the LED, for example, a white medium, for example, a predetermined amount of transmission of the CIS before entering the banknote. By applying the image value (CIS transmittance) reflecting the LED deterioration with time by attaching to the side area where the bill is not transferred in To perform.

In another embodiment, when a bill is entered, a bill image recognition operation is performed by multiplying a table parameter value created by considering a CIS transmission amount through the medium by the bill image output value.

In addition, as another embodiment, the bill image recognition operation may be performed using the gain value and the table parameter value as the corrected value of the bill image output.

3 is a block diagram 300 showing the configuration of the banknote identifier of the present invention.

Referring to FIG. 3, a banknote identifier employing an image sensor, for example, a CIS, includes an image sensor 302, a light emitting element 301, an analog-to-digital converter (ADC; 304), a RAM (RAM), and a center. It includes a processing unit (CPU) 308, a control logic unit 310, an acquisition detection sensor 312, an address control unit 314, a motor 316, an EPROM 320, and a display unit 322.

When a predetermined bill (not shown) is obtained in a bill identifier employing the image sensor configured as described above, the acquisition detection sensor 312 detects it. When the receipt of the bill is detected, the motor 316 is rotated, and a pulse according to the rotation of the motor 316 is output from the encoder 318. The CPU also controls the image sensor 302 to read data based on the output light of the light emitting element 301. When the central processing unit 308 transmits a control signal to the control logic unit 310 through the address control unit 314, the control logic unit 310 generates a predetermined start signal (SI) for driving the image sensor 302. And driving pulse (SCLK) are generated. When the control signals SI and SCLK generated by the control logic unit 310 are input to the image sensor 302, the image sensor 302 is driven to extract image data of the received bills.

Analog-to-digital converter 304 converts the image data into digital data and stores it in RAM 306. The central processing unit 308 reads the digital data of the bill stored in the RAM 304 and compares it with predetermined reference data stored in the EPROM 320 to identify the authenticity of the received bill, and the result. Is displayed on the display unit 322.

In the configuration and operation as described above, a predetermined medium, for example, a white medium (e.g., 530 of FIG. 5A) in a predetermined portion of the light emitting element 301, for example, a side region portion in which a bill is not transferred in the LED bar. ), The control unit 308 controls the CIS gain according to the result of acquiring an image value (for example, the CIS transmission amount) reflecting the degradation of the LED 301 with time before entering the banknote. ) To perform the banknote image recognition operation with the corrected value.

In another embodiment, when a bill is entered, the bill image recognition operation is performed by multiplying the bill parameter image output value by multiplying the table parameter value shown in Table 1 by taking into account the CIS transmission amount obtained through the medium. It is performed under the control of the controller.

4 is a view showing a configuration in which the banknote transfer and the image is obtained in the present invention.

In FIG. 4, reference numeral 410 denotes an optical sensor 410 capable of detecting the thickness and size of the banknote according to the amount of light passing through the banknote. In addition, corresponding to the image sensor 302 of FIG. 3, the image acquisition means 430 for extracting the pattern and color tone of the bill image is shown.

Hereinafter, the features of the present invention will be described with reference to the drawings.

That is, a predetermined medium is attached to the light emitting means, a parameter considering the transmission amount of the image sensor through the medium is set, the transmission amount of the image sensor through the medium is checked, and the obtained transmission amount is compared with a predetermined reference value. Through this, the banknote image output value is corrected by reflecting the gain value of the image sensor and / or by applying the set parameter to output a uniform image value.

5A and 5E are diagrams illustrating a process of confirming the CIS permeation amount before entering bills.

FIG. 5A shows a predetermined medium 530 attached to a side portion of an LED bar (not shown) corresponding to the side portion 520 of the CIS 510 in checking the transmission amount of the image sensor CIS as described above. It is a figure which showed one thing.

FIG. 5B is a view showing that light passes through the CIS LED bar 540 and the CIS sensor 550 corresponding to the light emitting device 301 and the image sensor 302 in FIG. 3.

FIG. 5C is a graph 560 showing that LED characteristics deteriorate with time through the white medium 530 in FIG. 5A.

As shown in the figure, it can be seen that the CIS transmission amount (vertical portion) decreases with time (horizontal portion).

FIG. 5D is an exemplary diagram illustrating a deteriorated CIS transmission amount in each part illustrated in FIG. 5C. The control unit may obtain a transmission amount by reading a pixel value of a specific part 570.

FIG. 5E illustrates a graph 580 in which the CIS transmittance is constantly output even when the LED deteriorates with time when the white medium 530 is not used in FIG. 5A.

5A-5E will be described further.

LED characteristics become less efficient over time. However, in the image image through which light is directly transmitted (a bill image in a portion other than the white medium 530 in FIG. 5A), even if the brightness of the transmitted light changes, as shown in FIG. 255), so the amount of direct transmission does not seem to change over time. (See FIG. 5E).

Therefore, in order to realize the object (reflecting LED degradation over time) in the present invention

As shown in FIGS. 5A / 5B, the white medium is inserted into the remaining portion 530 rather than the bill transfer path portion of the CIS LED bar.

When inserting the white medium, as shown in Figure 5c when the LED is turned on and the background of the image (box portion 570 of Figure 5d) it can be seen that it becomes dark over time. By using the above method, the transmission image of the white medium portion is acquired using the CIS at the time of driving before the banknote is inserted into the banknote recognition module, and the controller controls the sum (average value) of the predetermined portion of the background image (570 of FIG. 5D). It calculates and calculates pixel value of.

When acquiring an image, the white medium portion (530 of FIG. 5A) is almost black (FIG. 5D) as shown below. If the specific part 570 of 5d is checked before driving, the current LED state (brightness state of the transmitted LED) can be checked.

In FIG. 5D, when the CIS is read at a time driven before the banknote is inserted into the banknote recognition module, the same comes out as in FIG. 5D. At present, since the banknote does not pass, all the light is transmitted and the image to be used is white (the black part is the part covered by the white medium in FIG. 5A).

6A and 6B show images output through controlling gain of the CIS based on the result of confirming the CIS transmission amount through the white medium portion. That is, the image obtained by adjusting the CIS gain with the sum of the backgrounds obtained in FIG. 5 (particularly, FIG. 5D) is shown.

As shown in FIG. 6A, when the image becomes dark based on the LED characteristic, a corrected image may be obtained as illustrated in FIG. 6B by checking the image of the white medium portion (FIG. 5D) and adjusting the CIS gain.

In the present invention, the CIS gain adjusting method reads a transmission value of the CIS through a white medium in real time and gains a gain greater than or equal to a predetermined reference value, and gain is +1 (when smaller than the reference value), -1 (reference value). Greater than).

Figures 7a-7c relates to confirming the CIS permeation amount after entering the bill, the actual operation is the same as obtaining the CIS permeation amount in Figs. 5a-5e (particularly Fig. 5d).

FIG. 7A shows that the transmitted background image value of the LED in the predetermined media portion of the CIS is “2101”, FIG. 7B is “1913”, and FIG. 7C is “556”.

Therefore, it can be seen that the sharpness of each image varies according to the image value.

That is, when the bill passes through the module and the CIS sensor scans, the image shown in FIGS. 7A-7C is displayed. The parts that appear black (710, 720, 730) are the parts where white media is transmitted by the CIS LEDs (they look like black but are not really black).

The sum of specific portions 710a, 720a, and 730a is obtained for each image input in the same manner as in FIG. 5. The transmitted brightness of the LED is determined by checking the size of the sum for each input image.

8A and 8B illustrate embodiments in which an output image is adjusted by multiplying a parameter based on a CIS transmission amount.

FIG. 8A corresponds to FIG. 7C and may output a corrected image as illustrated in FIG. 8B by multiplying a predetermined parameter value. Table 1 below is one embodiment table of parameter value setting by CIS permeation amount. In the present invention, since the sum is 5X5 (pixel), the sum range is 0 to 6375 (255 * 5 * 5)).

           CIS penetration           Parameter             0-500              * 5            500-600              4.5            600-700              * 4            700-800              3.5            800-900              * 3            900-1000              2.5            1000-1200              * 2            1200-1400              * 1.5            1400-1500              1.2            1500-              * One

7A-7C, if the sum of the specific portions transmitted through the white medium is obtained, a large amount of bills are emitted in the case of continuous emission, so if the brightness of the LED becomes dark while receiving bills, the parameters written in the table in Table 1 above are used. Selected multiply the input image by a certain value, or adjust the CIS gain in preparation for the bill quality of the next input image to process the optimal image to determine the recognition element of the bill can be processed bill recognition.

9 is a schematic flowchart 900 of the present invention showing the banknote image output correction by the CIS transmission amount.

First, a predetermined medium is attached to the image sensor, and parameter setting considering the transmission amount of the image sensor CIS through the medium should be premised.

Check the penetration of the image sensor before entering bills. (S 901). The gain value of the image sensor is reflected based on a result of comparing the acquired transmission amount with a predetermined reference value. (S 903). Further, the banknote image output value is corrected by applying the set parameter based on the transmission amount confirmed after entering the banknote. (S 905, S 907).

10 is a flowchart 1000 showing the amount of transmission of the image sensor before entering banknotes.

As shown in Fig. 10, a predetermined medium is attached to the light emitting means (S 1001).

Check the transmission amount of the image sensor through the medium (S 1003).

The obtained transmission amount is compared with a predetermined reference value. (S 1005).

Based on the comparison result, the image sensor is controlled by reflecting the gain value in the image sensor to obtain a bill image. (S 1007, S 1009).

11 is a flowchart 1100 illustrating the amount of transmission of the image sensor after entering banknotes.

As shown in Fig. 11, a predetermined medium is attached to the light emitting means (S 1101).

A parameter considering the transmission amount of the image sensor through the medium is set. (S 1103).

Check the transmission of the image sensor through the medium. (S 1105).

The banknote image output value is corrected by applying the set parameter based on the confirmed transmission amount. (S 1107).

As described above, the present invention is to perform banknote recognition in consideration of the LED (Light Emitting Device) characteristics, which are included in the banknote recognition module, and the CIS (Contact Image Sensor) value of the imaging means, the LED characteristic is time And / or check the LED transmission amount (hereinafter referred to as CIS transmission amount) in the CIS by a predetermined white medium to compensate for the decrease in recognition quality of the banknote image as the output efficiency decreases based on temperature. 1) adjust the CIS output gain (GAIN), which is one of the predetermined values, and then transfer the bills to obtain a corrected image output value; or 2) convert the parameter value set by the CIS transmission amount as another one of the predetermined values of the CIS. By obtaining the corrected image output value by multiplying the image output value, an image of a uniform bill can be obtained.

As mentioned above, preferred embodiments of the present invention described above are disclosed for the purpose of illustration, and those skilled in the art can improve other various embodiments within the spirit and technical scope of the present invention disclosed in the appended claims below. Changes, substitutions or additions will be possible.

According to the implementation of the present invention, it is possible to obtain a uniform image without being affected by the temperature and time characteristics of the CIS LED.

In addition, the quality of the input image can be controlled by searching for the brightness of light passing through the white medium in real time.

Claims (12)

An image sensor; Light emitting means for emitting light to the image sensor; A memory unit in which at least one reference value of a transmission amount of an image sensor or a parameter value set in consideration of the transmission amount value is stored in contact with the light emitting means and formed in a portion of the light emitting means that is not a bill transfer path; And And a controller configured to reflect the gain according to the reference value or control at least one of the application of the parameter value to correct the banknote image output value. The banknote recognizing apparatus according to claim 1, wherein the predetermined medium is a white medium. delete        Attaching a predetermined medium; Confirming a transmission amount of the image sensor through the medium; Comparing the obtained transmission amount with a predetermined reference value; And Reflecting the gain value in the image sensor output based on the comparison result; Banknote recognition method comprising a. The method of claim 4, further comprising: obtaining a bill image by controlling an image sensor output based on the reflected gain value. The method of claim 4, wherein if the transmission amount is larger than a predetermined reference value, the gain is reflected by -1, and when the transmission amount is smaller than the reference value, the gain is reflected by +1. Attaching a predetermined medium; Setting a parameter in consideration of the amount of transmission of the image sensor through the medium; Confirming a transmission amount of the image sensor through the medium; And Correcting a banknote image output value by applying the set parameter based on the checked transmission amount. 8. The method according to claim 7, wherein the parameter value is set in inverse proportion to the magnitude of the transmission amount of the image sensor through the medium. Attaching a predetermined medium; Setting a reference value and a parameter value in consideration of the amount of transmission of the image sensor through the medium; Comparing the transmission amount of the image sensor through the medium with the reference value; Reflecting a gain value in the image sensor output based on the comparison result; Confirming a transmission amount of the image sensor through the medium; And And correcting a bill image output value by applying the set parameter value based on the checked transmission amount. 10. The method of claim 9, wherein the transmission amount of the image sensor through the medium is checked before or after the bill enters the bill module. The banknote recognition method according to claim 10, wherein the banknote reflects a gain value in the image sensor output based on a result of checking the amount of transmission before entering the banknote module. The banknote recognition method according to claim 10, wherein the banknote is applied with the parameter value based on a result of checking the transmission amount after entering the banknote module.

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