Be used to detect the apparatus and method of flaky material fluoroscopic image printing quality
Technical field
The present invention relates to the apparatus and method that are used to detect, relate in particular to the apparatus and method of the fluoroscopic image printing quality that is used to detect flaky material.
Background technology
At present, in order to increase anti-counterfeit capability such as flaky materials such as banknote, securities, stamp, antifalsification papers, in these flaky materials, be provided with fluoroscopic image mostly, special under the situation of banknote, this fluoroscopic image has three kinds of fluoroscopic images: (1) colorless fluorescent figure, yellowish orange; (2) colorless fluorescent numeral, reddish orange; (3) colorless fluorescent fiber has blue and yellow two kinds of colors.For above-mentioned fluoroscopic image, whether the quality and the colorless fluorescent fiber that need to check fluoroscopic image exist.Because the color of above-mentioned fluoroscopic image has four kinds, and the size of colorless fluorescent fiber is very little again and brightness is very weak, so, need a cover pick-up unit and finish above-mentioned complete inspection work.
The Chinese invention patent ZL 96194751.9 of Germany Giesecke ﹠ Devrient GmbH application on May 9th, 1996 has disclosed a kind of device that is used to detect page sheet material, this device has a lighting device, be used in detected overall optical spectral limit, continuously the page or leaf sheet material being thrown light on, also have a receiving device, it has the parallel charge-coupled device (CCD) array of two-lines at least.Each ccd array is provided with the light filter that is used for seeing through a certain SPECTRAL REGION light.Each light filter is through selected, so as to make at least one light filter work in the visible range and at least another one be operated in the invisible spectrum district.For detecting the light by diffuse reflection of page or leaf sheet material or transmission, each ccd array produces electric signal from the light that receives, and electric signal is handled in evaluating apparatus subsequently and compared with reference data, to realize the detection to described page or leaf sheet material.Though use the disclosed device of this patent of invention can the printing quality of the fluoroscopic image of page or leaf sheet material be detected, because the light source of this device employing is a full spectrum light source, energy consumption is bigger, the also corresponding minimizing of light source life.And the structure of this device is complicated, for example, because the light source that this patent of invention adopted is the sphere emission, inefficiency is so must increase reverberator, can obtain enough illumination intensities, and the diffused light that catoptron forms also can reduce the sharpness of image.In this device, need to use light source that the page or leaf sheet material is carried out continuously evenly illumination, can cause a problem like this, promptly, adopting under the situation of ccd array as receiving trap, might cause the brightness irregularities of the image of ccd array picked-up because of wide visual field problem, influence the degree of accuracy that detects to a great extent.In addition, this device can only could be differentiated banknote under the situation of banknote moving linearly, and the straight-line shake up and down of banknote, the equistability that swings problem is very big to the degree of accuracy influence that detects, the velocity ratio that this device detects banknote is less, and this speed can only be constant speed, otherwise very big distortion can appear in image.Under the situation of constant speed, the normal requirement of velocity-stabilization degree is higher than 2/10000ths, and be too high but this velocity-stabilization degree requires, and is to be difficult to realize.In addition, this device can not be checked above-mentioned 3 kinds of fluoroscopic images.
German patent application DE-OS3815375 shows a kind of page device of sheet material legitimacy that is used to detect, and it is made of a plurality of similar modules, and each module all has white light illumination device and the linear photodiode display of oneself.And, be provided with the light filter of the light in coloured light such as being used for seeing through red, green, blue for example or infrared spectrum zone in each module the place ahead.For the page or leaf sheet material is detected, the light that lighting device sends is through corresponding light filter and shine described page or leaf sheet material, is detected by described light filter and by linear photoelectric diode array by the irreflexive light of described page or leaf sheet material.Photodiode array converts the light of incident to corresponding signal, and handles subsequently.Use similar module to handle by light, guaranteed to be convenient to repair described device, still, also caused higher relatively cost of equipment simultaneously different color light or infrared spectral region.Owing to used photodiode array, the page or leaf sheet material can obtain scanning on its whole width.But used circuit more complicated, in addition since the intensity of light a little less than, the resolution that is obtained is lower, to the detection out of true of page or leaf sheet material.Since in page or leaf sheet material motion, occur shake up and down, swing and problem such as speed instability can make the image that collects very big distortion occur, thereby greatly reduce the precision of check.In addition, this device can not detect multiple fluoroscopic image.
Chinese invention patent ZL 97181461.9 has disclosed a kind of equipment, and it has a luminescent system, and it uses pulse excitation rayed sheet material.Sensor is detecting the light intensity that sheet material sends with the dark of pulse excitation light during mutually during the exposing of pulse excitation light respectively.By means of calculation element according to pulse excitation light mutually with secretly mutually in detected intensity derivation fluorescence luminous intensity and phosphorescent luminous intensity.In order to guarantee to carry out the pre-irradiation of possible maximum duration, in the areas of web material of sensor preferred detection light-emitting device irradiation and towards the luminous intensity of area terminal with high strength.In addition, the size of selection sheet material irradiated region makes it the manyfold into required resolution.The structure of this equipment is complicated, and can only detect the quality of sheet material according to fluorescence luminous intensity and phosphorescent luminous intensity, and can not detect the printing quality of sheet material according to fluorescence or phosphor pattern.
The Chinese utility model patent ZL02205868.0 that the inventor applied on March 6th, 2002 discloses a kind of pick-up unit that is used for opening greatly banknote printing quality checking machine band combined probe, it comprise cabinet, greatly open banknote phoresy cylinder, shaft-position encoder, near the light source of cylinder, in cabinet, be provided with two groups or more linear array CCD camera group along the axial direction of cylinder, each ccd video camera and camera lens front end thereof are equipped with optical filter, and the rotating shaft of cylinder is provided with a shaft-position encoder.Light source irradiation is arranged on the big banknote of opening on the cylinder, the banknote reflection on the linear array CCD camera picked-up cylinder or the light of diffusion, opened the image of banknote greatly, adopt different types of optical filter (as ultraviolet, fluorescence, redness or infrared etc.), can make and respectively organize the big banknote image of opening that ccd video camera absorbs different spectrum.Because the light source that this device adopts is a full spectrum light source, by using different light filters to see through the light of different spectrum, so that ccd video camera absorbs the image of different spectrum, thereby caused the generation of the not enough situation of intensity of illumination, in this case, the image that absorbs by ccd video camera can become clear inadequately, is unfavorable for opening greatly the detection of banknote printing quality.In addition, this utility model patent has only disclosed the capturing apparatus that is used for pickup image, does not have to disclose the device of how image that absorbs being handled.
Therefore, in order to overcome the defective of above-mentioned prior art, need a kind of structure simple relatively, with low cost, the apparatus and method that can detect the fluoroscopic image printing quality of flaky material with higher resolution.
Summary of the invention
Fundamental purpose of the present invention is to provide a kind of at least one defective that has overcome above-mentioned prior art, can check the pick-up unit and the method for the fluoroscopic image printing quality of flaky material at a high speed.
One object of the present invention is to provide a kind of pick-up unit and method of fluoroscopic image printing quality of accurately fast detecting flaky material.
Another object of the present invention is to provide a kind of and can carry out pinpoint apparatus and method the pick-up unit of the fluoroscopic image printing quality of checking flaky material.
The invention provides a kind of device that is used to detect flaky material fluoroscopic image printing quality, this device comprises: transmitting device, irradiation unit, receiving trap and signal conditioning package, this transmitting device is used to transmit this flaky material, and with a transmission speed this flaky material is moved towards a direction; This irradiation unit is used to light shine this flaky material; This transmitting device is a cylinder, and flaky material is attached on the cylinder, rotates with this cylinder.This irradiation unit is made of ultraviolet source, and ultraviolet lighting is mapped on the flaky material; This receiving trap comprises at least one linear array CCD camera group, and this linear array CCD camera group comprises at least two linear array CCD cameras, and this linear array CCD camera is provided with optical system and ultraviolet filter.
This ultraviolet source can with ultraviolet light evenly or uneven irradiation to flaky material.Be placed with target on cylinder, this target comprises five images, that is: first image, second image, the 3rd image, the 4th image and the 5th image.
First image is used for the optical axis of the optical system of linear array CCD camera group is adjusted to straight line, and it comprises:
Four blockages are positioned at the central authorities of the 4th target, and it is centered close on the straight line, and size equals the resolution dimensions of ccd video camera, and spacing is 5 resolutions;
Upright dark black triangle is positioned at the below of the 4th target, and to the scopes of 150 degree, its top center with left/right second blockage overlaps drift angle at 90 degree; And
The dark black triangle that stands upside down is positioned at the top of the 4th target, drift angle be 90 degree to the scopes of 150 degree, its top center with left/right the 3rd blockage overlaps.
Second image is used to adjust the symmetry of visual field up and down of the optical system of linear array CCD camera, and it comprises:
Superposed dark rectangle, it highly is 1/4 of a length; And
Be positioned at the right-angled trapezium striped of bottom, trapezoidal striped comprises that width is the light lines and the dark strokes of 1 resolution, and the length ratio on the long straight flange of right-angled trapezium striped and base is 3/4, the angle of hypotenuse and short right-angle side at 90 degree between 150 degree.
The 3rd image is used to adjust the focus state of the optical system of linear array CCD camera, and it comprises a rectangle striped group, and rectangle striped group comprises:
The light lines of wide 2 resolutions, it is positioned at the central authorities of rectangle striped; And
The alternate dark color of wide 1 resolution, light lines, its symmetry are positioned at the light lines both sides of wide 2 resolutions.
The 4th image is used to adjust the overlapping region of linear array CCD camera, and it comprises that four width are the dark strokes of 2 resolutions, two middle dark strokes be spaced apart 2 resolutions, the interval between the left side two dark strokes and the right two dark strokes is identical.
The 5th image is used to test transport function, and it comprises a rectangle striped group, and the rectangle striped comprises 5 symmetrical striped groups, and the corresponding normalized spatial frequency of the width of each striped difference, f/f
N=0.1,0.2,0.3,0.4 and 0.5.
In above-mentioned detection device, irradiation unit is configured in the position parallel with cylinder axis with receiving trap, have certain angle between the irradiates light direction of this irradiation unit and the optical axis of described ccd video camera, lighting device arrives the distance of cylinder axis less than receiving trap to the distance of cylinder axis; On transmitting device, also be provided with scrambler, be used to make flaky material, lighting device and receiving trap synchronous working.
In above-mentioned pick-up unit, this signal conditioning package comprises: harvester, treating apparatus, memory storage, input media, output unit; This harvester is used for the acquisition testing image; This treating apparatus is used to receive the detected image that harvester is gathered, and sets up template, and detected image and template are compared; This memory storage is used for store template and part detected image; This input media is used for input and detects and steering order, to change the transmission speed of template parameter and control transmission device; This output unit is used for comparative result is exported.In above-mentioned signal conditioning package, harvester can be an image pick-up card, and treating apparatus can adopt central processing unit or DSP image processor.
In above-mentioned detection device, ultraviolet source has adopted ultraviolet lamp tube, and ultraviolet lamp tube has the exit window of a special angle, and the fluorescent tube outside the exit window partly is coated with reflective membrane, is used for the light reflection ultraviolet line, also sees through Infrared, makes ultraviolet light see through exit window.
In above-mentioned pick-up unit, this irradiation unit light shines in the zone of the certain width of flaky material and length, and the width of this length and flaky material is identical or be slightly larger than the width of flaky material.
The present invention also provides a kind of method that is used to detect flaky material fluoroscopic image printing quality, may further comprise the steps: by the second best in quality flaky material is analyzed, set up the fluoroscopic image template; Use transmitting device to transmit this flaky material along a direction; The irradiation unit that use is used for launching ultraviolet light shines this flaky material, and it can be evenly to distribute or non-uniform Distribution that irradiation distributes; The receiving trap that use has a fluorescence filters can filter the interference of non-fluorescence and receive the fluorescence of this flaky material diffusion or reflection, and is translated into detected image; Use the signal conditioning package collection and handle this detected image; And use signal conditioning package that this detected image and template are compared, to detect the printing quality of this flaky material fluoroscopic image.
Also comprise in collection of above-mentioned use signal conditioning package and the step of handling this detected image: use harvester acquisition testing image; Use the detected image that treating apparatus receives and processing is gathered; Use special algorithm that this detected image and this fluoroscopic image template are compared by this treating apparatus; And output comparative result.
The step that receives the detected image of being gathered at above-mentioned use treating apparatus also comprises: use and gather the fluoroscopic image that the window collection need detect, to reduce the interference of data volume and the non-fluorescence data of elimination.
In the above-mentioned method that is used for detecting flaky material fluoroscopic image printing quality, the algorithm that is adopted is the image threshold detection algorithm.
The comparison step of being mentioned in said method also comprises: the duty of judging transmitting device, irradiation unit, signal conditioning package; Determine the general location of detected image, detected image is carried out the subregion fine positioning; Detected image is carried out related operation with respect to template, determine the overproof zone of detected image and the information of overproof numerical value; And according to statistical theory overproof area information is analyzed, determine the quality of detected image.
The step of using signal conditioning package that detected image is handled may further comprise the steps: detected image is carried out pre-service; Detected image is carried out binary conversion treatment; And detected image carried out the binary image inspection.
Above-mentionedly detected image is carried out pretreated step comprise: first gray threshold and second gray threshold are set, and first gray threshold is greater than second gray threshold; Gray scale in the detected image is defined as high brightness colorless fluorescent image more than or equal to the image of first gray threshold; Gray scale in the detected image is defined as intermediate light colorless fluorescent image less than first gray threshold and more than or equal to the image of second gray threshold; Gray scale in the detected image is defined as the colorless fluorescent image of low-light level less than the image of second gray threshold.
The above-mentioned step that detected image is carried out binary conversion treatment may further comprise the steps: first gray threshold, second gray threshold and the 3rd gray threshold are set, and first gray threshold is greater than second gray threshold, and second gray threshold is greater than the 3rd gray threshold; The gray scale of detected image is set to saturated gray level image more than or equal to the zone of first gray threshold, and remaining zone is set to full black area, thereby obtains the binary image of high brightness colorless fluorescent image; The gray scale of detected image is set to saturated gray level image more than or equal to second gray threshold less than the zone of first gray threshold, and remaining zone is set to full black area, thus the binary image of brightness colorless fluorescent image in obtaining; And the gray scale of detected image is set to saturated gray level image more than or equal to the 3rd gray threshold less than the zone of second gray threshold, and remaining zone is set to full black area, thereby obtains the binary image of low-light level colorless fluorescent image.
The above-mentioned step that detected image is carried out the binary image inspection comprises: set up the fluoroscopic image template; And will carry out matching operation through pretreated detected image and fluoroscopic image template.
The advantage of the apparatus and method of the fluoroscopic image printing quality that is used to detect flaky material provided by the invention is as follows:
1. the present invention has adopted the method for using the linear array CCD camera of being with fluorescence filters directly to absorb fluoroscopic image, and is simple in structure, the image definition height;
2. owing to adopted the target of the present invention's design, can adjust the position of linear array CCD camera group more exactly, make the linear array CCD camera group be in the optimum position;
3. inhomogeneous the compensating of light intensity of the absorption image that can produce the wide visual field problem owing to linear array CCD camera improved the homogeneity and the sharpness of detected image;
4. owing to adopted image threshold preprocess method, image binaryzation method and binary image matching process, make the calculated amount for the treatment of apparatus reduce greatly, detection speed is greatly improved, the accuracy of comparative result is significantly improved, and can check colorless fluorescent figure, colorless fluorescent numeral and colorless fluorescent fiber;
5. because flaky material is attached on the cylinder, and shake does not up and down swing, so the image that collects is not distortion almost;
6. owing to be used in combination scrambler simultaneously on the transmitting device, so allow the velocity of rotation of cylinder non-constant, reduced accuracy requirement to machinery, can adjust the velocity of rotation of cylinder, and can make transmitting device, irradiation unit, receiving trap synchronous working, improved accuracy of detection; And
7. because the present invention has used a kind of special ultraviolet lamp tube, it is provided with an exit window, has improved the brightness of directional lighting; Fluorescent tube outside the exit window partly is coated with light reflection ultraviolet and sees through the reflective membrane of infrared light, has formed the cold light pipe, thereby has increased the serviceable life of fluorescent tube.
8. owing to adopted special two light filters that see through wave band, can effectively see through fluoroscopic image, and suppress the interference of non-fluoroscopic image significantly.
Description of drawings
Fig. 1 is the structure principle chart according to pick-up unit of the present invention;
Fig. 2 is the circuit block diagram of the signal conditioning package in the pick-up unit shown in Figure 1;
Fig. 3 is the image according to the target that adopts in the pick-up unit of the present invention;
Fig. 4 is the partial enlarged drawing of the image of target shown in Figure 3;
Fig. 5 is the spectrum character diagram according to the ultraviolet filter that adopts in the pick-up unit of the present invention;
Fig. 6 a is the front view (FV) according to the uviol lamp that adopts in the pick-up unit of the present invention;
Fig. 6 b is the cross-sectional view according to the uviol lamp that adopts in the pick-up unit of the present invention;
Fig. 7 is the process flow diagram according to detection method of the present invention;
Fig. 8 is the process flow diagram of the treatment step in the detection method shown in Figure 7;
Fig. 9 is the process flow diagram of the pre-treatment step in the treatment step shown in Figure 8;
Figure 10 is the process flow diagram of the image binaryzation treatment step in the treatment step shown in Figure 8;
Figure 11 carries out the process flow diagram of the step that binary image checks to detected image in the treatment step shown in Figure 8; And
Figure 12 is the explanation block diagram of detection method of the present invention.
Embodiment
With reference now to description of drawings the present invention,, Fig. 1 is the structure principle chart of the disclosed flaky material fluoroscopic image quality detection device of the present invention.This pick-up unit 100 comprises transmitting device 101, irradiation unit 103, receiving trap 105, signal conditioning package 200.Transmitting device 101 is provided with scrambler 107, is used to make transmitting device 101, irradiation unit 103, receiving trap 105 synchronous workings.Flaky material is arranged on the transmitting device 101.Receiving trap 105 is provided with ultraviolet filter 109, is used for seeing through fluorescence.Irradiation unit 103 with irradiate light to the flaky material that is positioned on the transmitting device 101, receiving trap 105 receives from the fluorescence of this flaky material reflection or diffusion, and convert thereof into detected image, signal conditioning package 200 receives this detected image from receiving trap 105, and itself and the template of having set up in advance compared, thereby detect the printing quality of flaky material fluoroscopic image.In one embodiment of the invention, transmitting device 101 can comprise cylinder; Irradiation unit 103 can adopt ultraviolet source, be used to excite the fluoroscopic image of flaky material, in this embodiment, ultraviolet source is made up of uviol lamp, this uviol lamp is provided with one 20 degree to the emitter window between 40 degree, remainder outside the emitter window is coated with the reflective membrane that is useful on uv reflectance and transmits infrared, thereby constitutes the cold light pipe, has prolonged the serviceable life of fluorescent tube; Receiving trap 105 can comprise at least one linear linear array CCD camera group, and this linear array CCD camera group comprises at least two linear array CCD cameras, is provided with high light power camera lens at the front end of each linear array CCD camera, and it is provided with fluorescence filters.The F number of the high light power camera lens that is adopted is 0.85, thereby can obtain the low light level image of clear bright colorless fluorescent fiber.
Fig. 2 is the circuit block diagram of the signal conditioning package 200 in the pick-up unit 100 shown in Figure 1.Signal conditioning package 200 comprises harvester 202, treating apparatus 204, memory storage 206, input media 208 and output unit 210.Harvester 202 is used to gather the detected image from receiving trap 105; Treating apparatus 204 is used to set up template, handles the detected image that harvester 202 is gathered, and uses special algorithm that detected image and template are compared; Memory storage 206 is used for store template and part detected image; Input media 208 is used for input instruction, to change the transmission speed of template parameter and control transmission device; Output unit 210 is used to export comparative result.In according to one embodiment of present invention, harvester 202 can comprise image pick-up card, and treating apparatus 204 can be a central processing unit, also can be image processor.Memory storage 206 can be permanent storage or temporary storage.Input media 208 can comprise keyboard, mouse, touch-screen or its combination.Output unit 210 can be display device and I/O card.
Fig. 3 is the image of the target that adopts in the disclosed pick-up unit of the present invention.Target is used for before the pick-up unit that uses the printing quality that detects flaky material the performance parameter of receiving trap being adjusted to optimum condition.Before detecting, need adjust the position and the parameter of receiving trap 105 (being the linear array CCD camera group in the present embodiment).Method is: target is placed on the transmitting device 101, with receiving trap 105 bornb sights, manually or automatically adjusts the position and the parameter of receiving trap 105, till satisfying the needed performance index of detection.
Fig. 4 is the partial enlarged drawing of the image of target shown in Figure 3.First image is used for the optical axis of the optical system of linear array CCD camera is adjusted to straight line, there are four blockages at the middle part of this image, the size of each blockage equals the resolution dimensions of linear array CCD camera, the straight line that center by these blockages is linked to be is exactly the datum line of target, is exactly to adjust to the optical axis of the optical system of each linear array CCD camera on this datum line during adjustment.Second image is used to adjust the symmetry of visual field up and down of the optical system of linear array CCD camera.The 3rd image is used to adjust the focus state of the optical system of linear array CCD camera.The 4th image is used to adjust the overlapping region of linear array CCD camera.The 5th image is used to test transport function.
First image comprises: four blockages, be positioned at the central authorities of the 4th target, and it is centered close on the straight line, and size equals the resolution dimensions of ccd video camera, and spacing is 5 resolutions; Upright dark black triangle is positioned at the below of the 4th target, and to the scopes of 150 degree, its top center with left/right second blockage overlaps drift angle at 90 degree; And the dark black triangle that stands upside down, be positioned at the top of the 4th target, drift angle be 90 degree to the scopes of 150 degree, its top center with left/right the 3rd blockage overlaps.
Second image comprises: superposed dark rectangle, and it highly is 1/4 of a length; And the right-angled trapezium striped that is positioned at the bottom, trapezoidal striped comprises that width is the light lines and the dark strokes of 1 resolution, and the long straight flange of right-angled trapezium striped is 3/4 with the length ratio on base, and the angle of hypotenuse and short right-angle side is between 90 degree are spent to 150.
The 3rd image comprises a rectangle striped group, and this rectangle striped group comprises: the light lines of wide 2 resolutions, and it is positioned at the central authorities of rectangle striped; And the alternate dark color of wide 1 resolution, light lines, its symmetry is positioned at the light lines both sides of wide 2 resolutions.
The 4th image comprises that four width are the dark strokes of 2 resolutions, two middle dark strokes be spaced apart 2 resolutions, the interval between the left side two dark strokes and the right two dark strokes is identical.
The 5th image comprises a rectangle striped, and this rectangle striped comprises 5 symmetrical striped groups, and the corresponding normalized spatial frequency of the width of each striped difference, f/f
N=0.1,0.2,0.3,0.4 and 0.5.
Fig. 5 is the spectrum character diagram of the ultraviolet filter that adopts in the disclosed pick-up unit of the present invention.This fluorescence filters is one of critical component of pick-up unit of the present invention, its spectrum character diagram as shown in Figure 5, as can be seen from the figure, this light filter has two to see through wave band: (1) 400~480nm; (2) 560~680nm.The former can see through blue-fluorescence, and the latter can see through yellow, yellowish orange and reddish orange fluorescence, can also suppress the interference of the light of ultraviolet source, its all band of visible light and near-infrared band simultaneously.
Fig. 6 a is the front view (FV) according to the uviol lamp that adopts in the pick-up unit of the present invention.Fig. 6 b is the cross-sectional view according to the uviol lamp that adopts in the pick-up unit of the present invention.As can be seen from the figure, uviol lamp 600 comprises an exit window 602, and this exit window 602 is spent between 40 degree 10 to the angle of uviol lamp axis, is preferably 30 degree in the present embodiment.It will be appreciated by those skilled in the art that this angle can change with concrete application.Scribble reflective membrane 604 on the wall of the fluorescent tube part that exit window is outer, be used for light reflection ultraviolet, and see through infrared light.
Fig. 7 is the process flow diagram of the disclosed detection method of the present invention.This detection method may further comprise the steps: before detecting beginning, need to use target to adjust the position and the parameter of receiving trap 105.In step 702, use transmitting device along direction transmission flaky material; In step 704, use irradiation unit that flaky material is shone; In step 706, use the receiving trap that has ultraviolet filter to receive the fluorescence of flaky material diffusion or reflection, and be converted into detected image; In step 708, use signal conditioning package 200 acquisition testing images; In step 710, use 200 pairs of detected image of signal conditioning package to handle.
Fig. 8 is the process flow diagram of the treatment step in the detection method shown in Figure 7.Further comprising the steps of in calculation procedure shown in Figure 7 710: as, detected image to be carried out pre-service in step 802; In step 804, detected image is carried out binary conversion treatment; In step 806, detected image is carried out the binary image inspection.
Fig. 9 is the process flow diagram of the pre-treatment step in the treatment step shown in Figure 8.In step 902, the first gray threshold g1 and the second gray threshold g2 are set, g1 is greater than g2; In step 904, gray scale in the detected image is defined as the colourless digital phosphor image of high brightness more than or equal to the image of first gray threshold; In step 906, with gray scale in the detected image less than first gray threshold and be defined as the colorless fluorescent image of intermediate light more than or equal to the image of second gray threshold; In step 908, gray scale in the detected image is defined as the colorless fluorescent fibre image of low-light level less than the image of second gray threshold.
Figure 10 is the process flow diagram of the image binaryzation treatment step in the treatment step shown in Figure 8.In step 1002, the first gray threshold g1, the second gray threshold g2 and the 3rd gray threshold g3 are set, wherein, g1 is greater than g2, and g2 is greater than g3; In step 1004, the gray scale of detected image is set to saturated gray level image more than or equal to the zone of the first gray threshold g1, and remaining zone is set to full black area, thereby obtains the binary image of the colourless digital phosphor image of high brightness; In step 1006, the gray scale of detected image is set to saturated gray level image more than or equal to the second gray threshold g2 less than the zone of the first gray threshold g1, and remaining zone is set to full black area, thus the binary image of brightness colorless fluorescent image in obtaining; In step 1008, the gray scale of detected image is set to saturated gray level image more than or equal to the 3rd gray threshold g3 less than the zone of the second gray threshold g2, and remaining zone is set to full black area, thereby obtains the binary image of low-light level colorless fluorescent fiber.
Figure 11 carries out the process flow diagram of the step that binary image checks to detected image in the treatment step shown in Figure 8.In step 1102, set up the fluoroscopic image template; In step 1104, will carry out matching operation through pretreated detected image and fluoroscopic image template.When setting up template, need choose 50 to 100 or more up-to-standard flaky material earlier, with their mean value of respective image as digital phosphor binary image template and two kinds of binary image templates of colorless fluorescent binary image template.When detecting, the binary image of flaky material to be detected is carried out matching operation with corresponding binary image template, mate when fine when the two, detected flaky material has been product, is waste product and mate when bad.In above-mentioned detection method, detect the position of colourless digital phosphor image and the position of colorless fluorescent image by the centre of gravity place that calculates binary image.
Figure 12 is the explanation block diagram to detection method of the present invention.As can be seen from the figure, receive detected image with receiving trap 105 (having adopted the black and white linear array CCD camera in the present embodiment) earlier; Use 202 pairs of detected image of harvester to gather then; The effect of scrambler 107 is to make receiving trap 105 and harvester 202 synchronous workings; Harvester sends to signal conditioning package with the detected image that collects, and by it the image that collects is compared with the template of correspondence respectively; As we can see from the figure, in an embodiment of the present invention, be provided with three threshold value: g1, g2 and g3, wherein, g1 is greater than g2, and g2 is greater than g3; The gray scale of detected image is set to saturated gray level image more than or equal to the zone of g1, and remaining zone is set to full black area, thereby obtains the binary image of colourless digital phosphor image; The gray scale of detected image is set to saturated gray level image more than or equal to g2 less than the zone of g1, remaining zone is set to full black area, thereby obtain the binary image of colorless fluorescent image, and corresponding with it the respectively template of these two kinds of images is compared analysis; In addition, the gray scale of detected image is set to saturated gray level image more than or equal to g3 less than the zone of g2, and remaining zone is set to full black area, thereby obtains the binary image of colorless fluorescent fiber, after its analysis, can judge whether there is the colorless fluorescent fiber in the flaky material.Then, will compare with analysis result and send to output unit 210.Up-to-standard flaky material is sent most intimate friend's product storehouse, flaky material off quality is sent to the bad product storehouse.If detect bad product, then make alarm equipment alarm, the notifying operation personnel.Pick-up unit 100 of the present invention can also be provided with storer, is used for information such as store template, part detected image, statistics.Printer can also be set, be used for print image and statistics.
Detection method provided by the present invention and device can be used to detect the fluoroscopic image printing quality of flaky materials such as banknote, securities, antifalsification paper.The above is the preferred embodiments of the present invention only, is not limited to the present invention, and for a person skilled in the art, the present invention can have various changes and variation.Within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within the claim scope of the present invention.