CN109151451B - Binocular night vision device resolution detection method - Google Patents
Binocular night vision device resolution detection method Download PDFInfo
- Publication number
- CN109151451B CN109151451B CN201810522559.9A CN201810522559A CN109151451B CN 109151451 B CN109151451 B CN 109151451B CN 201810522559 A CN201810522559 A CN 201810522559A CN 109151451 B CN109151451 B CN 109151451B
- Authority
- CN
- China
- Prior art keywords
- resolution
- pattern
- coordinate
- night vision
- vision device
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000004297 night vision Effects 0.000 title claims abstract description 26
- 238000001514 detection method Methods 0.000 title claims abstract description 15
- 230000005855 radiation Effects 0.000 claims abstract description 7
- 238000005286 illumination Methods 0.000 claims abstract description 3
- 238000000034 method Methods 0.000 claims description 20
- 238000012163 sequencing technique Methods 0.000 claims 1
- 230000007547 defect Effects 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000011900 installation process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N17/00—Diagnosis, testing or measuring for television systems or their details
- H04N17/002—Diagnosis, testing or measuring for television systems or their details for television cameras
Abstract
The invention discloses a binocular night vision device resolution detection method, which comprises the following steps: step S1, collecting an image of a resolution target plate passing through a binocular night vision device under illumination, wherein the resolution target plate is provided with a positioning pattern and a resolution pattern for judging the resolution value of the binocular night vision device, the resolution target is a radiation type resolution plate, and the center of the positioning pattern is located at the center of the resolution pattern; step S2, according to the positioning pattern in the collected image, detecting the positioning pattern, realizing the positioning of the center of the resolution pattern, establishing polar coordinates by taking the resolution center as the origin, and solving the radius of the polar coordinates of each point of the resolution pattern; and step S3, stepping to 1 according to the radius of the polar coordinate in the original image of the collected image, calculating the contrast of the resolution light and dark spokes from small to large, recording the radius of the polar coordinate when the contrast of the resolution is not less than a contrast threshold value, and determining the resolution value according to the radius of the polar coordinate, the number of the light and dark spokes and the size at the moment, namely the resolution of the binocular night vision device.
Description
Technical Field
The invention relates to a scheme for automatically detecting the resolution of a night vision device, in particular to a method for detecting the resolution of a binocular night vision device.
Background
The resolution of a night vision device describes the ability to see tiny objects through the night vision device. At present, an image detection method is adopted to detect that the resolution test can only be carried out on the patterns by discrete grouping lines, in addition, a test system can generate the inclination of a resolution target plate, the inclination of a lens and the like in the installation process, and errors can be generated in the software image processing.
Therefore, an automatic detection method and device for the resolution of the low-light night vision device are disclosed in the current Chinese patent application publication No. CN105391998A, but the method and the device do not adopt a radiation type resolution plate, and the collected image is influenced by the inclination of a lens and the inclination of a resolution target plate when the device is installed when the light and dark stripes of the resolution are extracted.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, provides a binocular night vision device resolution detection method, realizes the automatic detection of the low-light night vision device resolution, and adopts the technical scheme that:
a binocular night vision device resolution detection method is characterized by comprising the following steps:
step S1, acquiring an image of a resolution target plate passing through a binocular night vision device under illumination, wherein the resolution target plate is provided with a positioning pattern and a resolution pattern for judging the resolution value of the binocular night vision device, the resolution target plate is a radiation type resolution plate, and the center of the positioning pattern is located at the center of the resolution pattern;
step S2, according to the positioning pattern in the collected image, detecting the positioning pattern, realizing the positioning of the center of the resolution pattern, establishing polar coordinates by taking the center of the resolution pattern as an original point, and solving the radius of the polar coordinates of each point of the resolution pattern;
and step S3, stepping to 1 according to the radius of the polar coordinate in the original image of the collected image, calculating the contrast of the resolution light and dark spokes from small to large, recording the radius of the polar coordinate when the contrast of the resolution is not less than a contrast threshold value, and determining the resolution value according to the radius of the polar coordinate, the number of the light and dark spokes and the size at the moment, namely the resolution of the binocular night vision device.
In a preferred embodiment of the present invention, the positioning pattern is circular and opaque.
In a preferred embodiment of the present invention, in step S2, the positioning pattern is positioned by using a template matching method or a connected region method, the center coordinates of the positioning pattern are calculated by using a centroid method,
template matching method: firstly, a template of a positioning pattern is manufactured, the template of the pattern is subjected to correlation operation in the whole collected image, the obtained maximum value coordinate of the correlation is the central area coordinate of the positioning pattern, the mass center is solved in the two-dimensional neighborhood of the central area coordinate according to the mass center method, and the solved result is the central coordinate of the positioning pattern;
the connected region method: firstly, carrying out binarization processing on an acquired image, marking a connected region, removing a stripe region and a noise region according to the size of the region, obtaining a remaining positioning pattern region, obtaining a centroid according to the coordinate range of the positioning pattern region and a centroid method, and obtaining a result, namely a central coordinate of the positioning pattern.
In a preferred embodiment of the present invention, step S3 specifically includes:
extracting from the minimum resolution bright and dark stripes of the resolution target plate every timeSorting the pixel points with the radius increment of 1 in the polar coordinate pixel size according to the rotation angle, and searching the sorted maximum value ImaxAnd the coordinate of the target plate is obtained, and the minimum value I in the coordinate range of the dark stripe adjacent to the maximum value is obtained according to the proportional relation between the width of the light and dark stripe of the resolution spoke of the acquired image and the width of the light and dark stripe of the spoke of the target plate with the actual resolutionminThe contrast ratio V ═ I is calculatedmax-Imin)/(Imax+Imin) When the contrast V is larger than the contrast threshold, the light and dark stripes are considered to be distinguishable, otherwise, the light and dark stripes are considered to be indistinguishable; if it can be resolved, it is determined by the minimum value IminCalculating the maximum value in the coordinate range of the next adjacent bright stripe by the coordinate calculation, and then calculating the contrast; if the resolution cannot be achieved, calculating pixel points contained in the next polar coordinate radius according to the specific steps, repeating the steps until all light and dark stripes of a certain polar coordinate radius R are not smaller than a contrast threshold value, stopping calculation, and calculating the resolution according to the proportional relation between the image pixel size and the actual resolution target plate and the size relation between the spoke light and dark stripes.
In a preferred embodiment of the invention, the contrast is calculated taking the average pixel value in the neighborhood of the maximum or minimum as the maximum or minimum.
The invention applies the radiation type discrimination plate to prevent the collected image from being influenced by the inclination of a lens and the inclination of a resolution target plate when the device is installed when extracting the light and shade stripes of the resolution; because the width of the light and dark stripes of the radiation type discrimination plate is continuously changed, the precision and the resolution detection range of the detection equipment are improved.
Drawings
FIG. 1 is a resolution target plate according to an embodiment of the present invention.
FIG. 2 is an image acquired by an embodiment of the present invention.
Fig. 3 is a result of binarization processing of an image acquired in an embodiment of the present invention.
FIG. 4 shows the result of extracting the positioning pattern from the image collected by the embodiment of the present invention.
FIG. 5 is a schematic view of an image and polar radius acquired according to an embodiment of the present invention.
Fig. 6 presents a fringe pattern with a polar radius of 90 for an image acquired by an embodiment of the present invention.
Fig. 7 presents a fringe pattern with a polar radius of 100 for an image acquired by an embodiment of the present invention.
Fig. 8 presents a fringe pattern with a polar radius of 108 for an image acquired by an embodiment of the present invention.
Fig. 9 presents a fringe pattern with a polar radius of 109 for an image acquired by an embodiment of the present invention.
Detailed Description
The invention is further illustrated by the following specific figures and examples.
In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further explained below.
The resolution target board of the present invention is shown in fig. 1, and includes a positioning pattern and a resolution stripe, and the sampling image is shown in fig. 2.
In the present embodiment, the target plate of the differentiation plate is 16 light and dark stripes, and the image is first binarized as shown in fig. 3. And (4) marking a connected region, processing the resolution stripes, and extracting a positioning pattern, as shown in fig. 4. The center coordinates of the positioning pattern are obtained by the centroid method, and after the center coordinates are obtained, the polar radius and the argument of each pixel are obtained using the center coordinates as the origin, as shown in fig. 5.
The calculation is started from the minimum resolution bright and dark stripe of the resolution target plate, the polar coordinate radius of the minimum resolution bright and dark stripe of the resolution target plate in the embodiment is 50, the extracted pixel values are sorted from small to large according to the argument, then extreme values are searched, contrast operation is carried out according to two adjacent extreme values, and the average pixel value of a small area near the extreme values is taken as the extreme value for preventing the interference of noise in the acquired image. When the radius of the polar coordinate is 90, the calculated minimum contrast V is 0.3% as shown in fig. 6, when the radius of the polar coordinate is 100, the calculated minimum contrast V is 0.8% as shown in fig. 7, when the radius of the polar coordinate is 108, the calculated minimum contrast V is 1.9% as shown in fig. 8, and when the radius of the polar coordinate is 109, the calculated minimum contrast V is 2.3% as shown in fig. 9. According to the interpretation of the resolution by professionals and the contrast result calculated by a computer, V is 2% as the threshold value whether the resolution pattern is resolved, and then the resolution is converted into 1mmrad according to the proportional relation between the image and the real resolution target plate.
According to the binocular night vision device resolution detection method, the center is located through the locating pattern in the collected image, polar coordinate transformation is carried out by taking the locating center as the original point, the contrast of the contained pixel points is calculated according to the polar coordinate radius taking the step as the unit, and due to the fact that the radiation type resolution plate is adopted as the resolution target plate, the resolution detection precision and the detection range are improved, and errors caused by other factors such as rotation during installation are avoided.
The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (5)
1. A binocular night vision device resolution detection method is characterized by comprising the following steps:
step S1, acquiring an image of a resolution target plate passing through a binocular night vision device under illumination, wherein the resolution target plate is provided with a positioning pattern and a resolution pattern for judging the resolution value of the binocular night vision device, the resolution target plate is a radiation type resolution plate, and the center of the positioning pattern is located at the center of the resolution pattern;
step S2, according to the positioning pattern in the collected image, detecting the positioning pattern, realizing the positioning of the center of the resolution pattern, establishing polar coordinates by taking the center of the resolution pattern as an original point, and solving the radius of the polar coordinates of each point of the resolution pattern;
and step S3, stepping to 1 according to the radius of the polar coordinate in the original image of the collected image, calculating the contrast of the resolution light and dark spokes from small to large, recording the radius of the polar coordinate when the contrast of the resolution is not less than a contrast threshold value, and determining the resolution value according to the radius of the polar coordinate, the number of the light and dark spokes and the size at the moment, namely the resolution of the binocular night vision device.
2. The binocular night vision device resolution detection method of claim 1, wherein the alignment pattern is circular and opaque.
3. The binocular night vision device resolution detecting method of claim 1, wherein in step S2, the positioning pattern is positioned using a template matching method or a connected region method, center coordinates of the positioning pattern are calculated using a centroid method,
template matching method: firstly, a template of a positioning pattern is manufactured, the template of the pattern is subjected to correlation operation in the whole collected image, the obtained maximum value coordinate of the correlation is the central area coordinate of the positioning pattern, the mass center is solved in the two-dimensional neighborhood of the central area coordinate according to the mass center method, and the solved result is the central coordinate of the positioning pattern;
the connected region method: firstly, carrying out binarization processing on an acquired image, marking a connected region, removing a stripe region and a noise region according to the size of the region, obtaining a remaining positioning pattern region, obtaining a centroid according to the coordinate range of the positioning pattern region and a centroid method, and obtaining a result, namely a central coordinate of the positioning pattern.
4. The binocular night vision device resolution detecting method according to claim 1, wherein the step S3 specifically includes:
starting from the minimum resolution bright and dark stripes of the resolution target plate, extracting pixel points with the radius increment of 1 of the size of the polar coordinate pixel each time, sequencing according to the rotation angle, and searching the sequenced maximum value ImaxAnd the coordinate of the target plate is obtained, and the minimum value I in the coordinate range of the dark stripe adjacent to the maximum value is obtained according to the proportional relation between the width of the light and dark stripe of the resolution spoke of the acquired image and the width of the light and dark stripe of the spoke of the target plate with the actual resolutionminThe contrast ratio V ═ I is calculatedmax-Imin)/(Imax+Imin) When the contrast V is larger than the contrast threshold, the light and dark stripes are considered to be distinguishable, otherwise, the light and dark stripes are considered to be indistinguishable; if it can be resolved, it is determined by the minimum value IminCalculating the maximum value in the coordinate range of the next adjacent bright stripe by the coordinate calculation, and then calculating the contrast; if the resolution cannot be achieved, calculating pixel points contained in the next polar coordinate radius according to the specific steps, repeating the steps until all light and dark stripes of a certain polar coordinate radius R are not smaller than a contrast threshold value, stopping calculation, and calculating the resolution according to the proportional relation between the image pixel size and the actual resolution target plate and the size relation between the spoke light and dark stripes.
5. The binocular night vision device resolution detecting method of claim 4, wherein the contrast is calculated taking an average pixel value in the neighborhood of the maximum value or the minimum value as the maximum value or the minimum value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810522559.9A CN109151451B (en) | 2018-05-28 | 2018-05-28 | Binocular night vision device resolution detection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810522559.9A CN109151451B (en) | 2018-05-28 | 2018-05-28 | Binocular night vision device resolution detection method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109151451A CN109151451A (en) | 2019-01-04 |
| CN109151451B true CN109151451B (en) | 2020-09-25 |
Family
ID=64801883
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810522559.9A Active CN109151451B (en) | 2018-05-28 | 2018-05-28 | Binocular night vision device resolution detection method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109151451B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114143535B (en) * | 2022-02-08 | 2022-06-07 | 广东欧谱曼迪科技有限公司 | Imaging system performance test method and device, electronic equipment and storage medium |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101144842B (en) * | 2007-10-18 | 2010-11-03 | 上海交通大学 | Display device definition test card and its definition measuring method |
| CN101626518B (en) * | 2008-07-11 | 2011-06-29 | 比亚迪股份有限公司 | Method and system for detecting resolution of photographic device |
| RU2461853C1 (en) * | 2011-04-19 | 2012-09-20 | Открытое акционерное общество "Научно-исследовательский институт оптико-электронного приборостроения" (ОАО "НИИ ОЭП") | Method of determining photographic camera resolution and set of circular marks for realising said method |
| CN102353519B (en) * | 2011-06-03 | 2013-07-10 | 中国兵器工业第二〇五研究所 | Resolving power evaluation method for three-generation dim light image intensifier |
| US9307230B2 (en) * | 2012-06-29 | 2016-04-05 | Apple Inc. | Line pair based full field sharpness test |
| CN105959683B (en) * | 2016-05-16 | 2018-09-11 | 武汉虹识技术有限公司 | A kind of camera lens resolution detection method and device |
| CN106101697B (en) * | 2016-06-21 | 2017-12-05 | 深圳市辰卓科技有限公司 | Approach for detecting image sharpness, device and test equipment |
-
2018
- 2018-05-28 CN CN201810522559.9A patent/CN109151451B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109151451A (en) | 2019-01-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115601367B (en) | LED lamp wick defect detection method | |
| CN109325935B (en) | Power transmission line detection method based on unmanned aerial vehicle image | |
| CN102176228B (en) | Machine vision method for identifying dial plate information of multi-pointer instrument | |
| CN111551567B (en) | Object surface defect detection method and system based on fringe projection | |
| US5923776A (en) | Object extraction in images | |
| CN110047063B (en) | Material drop detection method, device, equipment and storage medium | |
| JP2016166853A (en) | Location estimation device and location estimation method | |
| CN110415296B (en) | Method for positioning rectangular electric device under shadow illumination | |
| CN107092905B (en) | Method for positioning instrument to be identified of power inspection robot | |
| CN106529551B (en) | Intelligent recognition counting detection method for round-like objects in packaging industry | |
| CN115841488B (en) | PCB hole inspection method based on computer vision | |
| JP2018096908A (en) | Inspection device and inspection method | |
| CN111476804A (en) | Method, device and equipment for efficiently segmenting carrier roller image and storage medium | |
| JP7404747B2 (en) | Workpiece surface defect detection device and detection method, workpiece surface inspection system and program | |
| CN109151451B (en) | Binocular night vision device resolution detection method | |
| CN114450711A (en) | Workpiece surface defect detection device and detection method, workpiece surface inspection system, and program | |
| JPH08335236A (en) | Restaurant payment system | |
| CN117036259A (en) | Metal plate surface defect detection method based on deep learning | |
| CN1228733C (en) | Finding objects in image | |
| CN109064496A (en) | A kind of change detecting method of remote sensing images object hierarchy | |
| US10331977B2 (en) | Method for the three-dimensional detection of objects | |
| CN114240984A (en) | Circular mark point edge extraction method and application thereof | |
| CN110853059B (en) | Image identification method for target ring number | |
| CN110070520B (en) | Pavement crack detection model construction and detection method based on deep neural network | |
| JP3675543B2 (en) | Image position measurement method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of invention: A Resolution Detection Method for Binocular Night Vision Apparatus Effective date of registration: 20230309 Granted publication date: 20200925 Pledgee: Industrial Bank Co.,Ltd. Shanghai Changning sub branch Pledgor: SHANGHAI JIUHANG ELECTRONICS CO.,LTD. Registration number: Y2023310000053 |
|
| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| PC01 | Cancellation of the registration of the contract for pledge of patent right |
Granted publication date: 20200925 Pledgee: Industrial Bank Co.,Ltd. Shanghai Changning sub branch Pledgor: SHANGHAI JIUHANG ELECTRONICS CO.,LTD. Registration number: Y2023310000053 |
|
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of invention: A Resolution Detection Method for Binocular Night Vision Devices Granted publication date: 20200925 Pledgee: Industrial Bank Co.,Ltd. Shanghai Changning sub branch Pledgor: SHANGHAI JIUHANG ELECTRONICS CO.,LTD. Registration number: Y2024310000234 |