CN106572282A - Method for measuring non-vignetting longest exposure time in external trigger light path switching system - Google Patents
Method for measuring non-vignetting longest exposure time in external trigger light path switching system Download PDFInfo
- Publication number
- CN106572282A CN106572282A CN201610935168.0A CN201610935168A CN106572282A CN 106572282 A CN106572282 A CN 106572282A CN 201610935168 A CN201610935168 A CN 201610935168A CN 106572282 A CN106572282 A CN 106572282A
- Authority
- CN
- China
- Prior art keywords
- light path
- vignetting
- exposure
- phase
- camera
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 20
- 230000007246 mechanism Effects 0.000 claims abstract description 23
- 230000033001 locomotion Effects 0.000 claims abstract description 9
- 230000010363 phase shift Effects 0.000 claims abstract description 9
- 230000000007 visual effect Effects 0.000 claims description 13
- 238000003384 imaging method Methods 0.000 claims description 5
- 230000000903 blocking effect Effects 0.000 claims description 3
- 239000004576 sand Substances 0.000 claims description 3
- 230000006641 stabilisation Effects 0.000 claims description 3
- 238000011105 stabilization Methods 0.000 claims description 3
- 239000007787 solid Substances 0.000 claims 1
- 230000001360 synchronised effect Effects 0.000 abstract description 7
- 238000005259 measurement Methods 0.000 description 4
- 230000033228 biological regulation Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- VIKNJXKGJWUCNN-XGXHKTLJSA-N norethisterone Chemical compound O=C1CC[C@@H]2[C@H]3CC[C@](C)([C@](CC4)(O)C#C)[C@@H]4[C@@H]3CCC2=C1 VIKNJXKGJWUCNN-XGXHKTLJSA-N 0.000 description 2
- 108010076504 Protein Sorting Signals Proteins 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 125000001475 halogen functional group Chemical group 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/70—Circuitry for compensating brightness variation in the scene
- H04N23/73—Circuitry for compensating brightness variation in the scene by influencing the exposure time
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/04—Synchronising
- H04N5/06—Generation of synchronising signals
- H04N5/067—Arrangements or circuits at the transmitter end
- H04N5/0675—Arrangements or circuits at the transmitter end for mixing the synchronising signals with the picture signal or mutually
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Mechanical Light Control Or Optical Switches (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Abstract
The invention provides a method for directly measuring the longest exposure time without vignetting in an external trigger light path switching system, which does not require a position sensor, a speed sensor and the like in the system, is closer to practical application and directly reflects the working characteristics of the system. The measuring method realizes the relative movement of light spots on the light path switching mechanism by changing the phase relation between the external trigger signal of the camera and the synchronous signal of the motor in the switching system; in the process of gradually changing the phase relation, finally respectively determining the critical moment when the light spot is just completely incident to the reflector (or the through hole) and just begins to cut the reflector (or the through hole) for the corresponding image output by the camera; in the process of gradually changing the phase relationship, the time when the gray scale of the image is reduced due to the phase shift is the two critical times, and the difference between the two critical times is the longest exposure time without vignetting.
Description
Technical field
The present invention relates to the measuring method without the most long time of exposure of vignetting in a kind of outer synchronous light path switched system, particularly
The method that most long exposure time is carried out by adjusting camera exposure trigger sequential.
Background technology
In some application scenarios, it is desirable to using a camera in the scene for not shooting different visual angles in the same time；At other
Application scenario, it is desirable to incident ray timesharing all the way is projected in different cameras.To reach both applications, need to light path
Switched in real time, the scene of different visual angles is introduced or by same visual angle by same camera by the motion of switching mechanism
Scene introduces different cameras.This synchronism switching system can be divided into internal trigger and external trigger two types.Internal trigger synchronization
Switched system provides trigger using the position on switching mechanism or switch sensor, defeated when light path cuts camera
Going out trigger pulse makes camera start exposure.External trigger synchronism switching system is synchronously believed when outer using the outside synchronizing signal for providing
Number arrive when require path switching mechanisms make just light path incision camera, and while trigger camera start exposure.
Fig. 1 gives a kind of typical synchronism switching system, and now which is briefly described.Fig. 1 a) led to by a motor
Crossing shafting drives switching mechanism to be rotated, and is spaced and shoots the scene introducing camera of visual field 1 and visual field 2.Its switching machine
The layout of structure such as Fig. 1 b) shown in, in a discoidal mechanism, there are two reflecting mirrors (a, c position) and two to lead to uniformly at intervals
Hole (b, d position).When reflecting mirror a and reflecting mirror c proceed to light path, visual field 1 enters camera；When through hole b and through hole d proceed to light path
When, visual field 2 enters camera.If the system is operated in interior synchronous triggering, system meeting foundation is installed on reflecting mirror a and reflecting mirror c,
And the measurement situation triggering camera exposure of the sensor on through hole b and through hole d positions；If the system work is synchronous outside triggering
Shi Zeying makes reflecting mirror a, through hole b, reflecting mirror c and through hole d proceed to camera light path successively when outside lock-out pulse arrives
In.
In design, this light path switched system usually requires that projection of the launching spot at switching mechanism is less than switching machine
The reflecting mirror or clear size of opening of structure, such as Fig. 1 b) shown in.During due to camera exposure between launching spot and reflecting mirror (or through hole)
There is relative motion, when launching spot side cuts out reflecting mirror (or through hole) edge, generate gradually as blessing mechanism blocks
Halo effect, in some sensitive systems is also possible to form ghost image.One good synchronization scenario should be when synchronizing signal arrives
Make launching spot all cut just reflecting mirror (or through hole), and exposure time is not to be exceeded that hot spot is all cut into and just cuts
Duration between going out, the duration are without the most long time of exposure of vignetting.
In external trigger light path switched system, the most easy method that measures without the most long time of exposure of vignetting is adopted by synchronous
The angle and velocity information of collection switching mechanism is carrying out mathematics estimation.But, this method requires that system possesses angle and speed
Sensor, and its spot size for being used to calculate is Design Theory value, it is impossible to the operating characteristic of direct reacting system.
The content of the invention
The present invention provides a kind of method without the most long time of exposure of vignetting in directly measure external trigger light path switched system, no
Requirement system has position and velocity sensor etc., closer to practical application, the operating characteristic of direct reacting system.
The solution of the present invention is as follows：
According to the principle that vignetting is formed, if light path is not fully cut or is cut out by switching mechanism in the camera exposure time,
Occur target to be blocked and can not be imaged or reduce imaging gray scale.The present invention is same with motor by changing camera exposure signal
The phase relation of step signal, detects the method for average gray of picture carrying out the measurement of the most long time of exposure of vignetting.I.e.：Change phase
Machine external trigger signal phase can realize relative motion of the hot spot on path switching mechanisms, by gradually changing camera external trigger
Signal and the phase relation of motor in synchrony signal, while compareing corresponding image, finally determine that glossing up enters just completely respectively
It is mapped to reflecting mirror (or through hole) and has just cut out just the critical moment of reflecting mirror (or through hole)；Gradually change the mistake of phase relation
Cheng Zhong, because of phase shift so that the moment that the gray scale of image declines is the two critical moments, the difference of the two critical moments
As without the most long time of exposure of vignetting.
To obtain more accurate result, a phase relation be can often change, multiple image, statistical average gray scale preserved
Value；Come whether multilevel iudge gray scale declines with average gray value.
Specifically can realize according to following steps：
1) integrating sphere is placed in light path switched system visual field, substitute the synchronous letter of light path switched system using waveform generator
Number source, makes output level and sequential relationship and the requirement one of the light path switched system to external synchronization signal of each passage of waveform generator
Cause；
2) the camera exposure time is set for a fixed value, is made integrating sphere into visual field and without blocking, is gathered now camera figure
Picture, records the initial pictures for P0；
3) waveform generator and light path switched system are opened, the 4) step is proceeded to after path switching mechanisms spin stabilization；
4) adjust the phase place of the synchronizing signal of waveform generator connection camera channel so as to which phase deviation is in former phase place i milli
Second；
5) now camera image is gathered, it is P to record the image under side-play amount ii；
6) observe that target imaging brightness proceeds to the 7) step when substantially reducing, otherwise change i values and proceed to the 4) step；
7) the initial pictures P to recording0And the image P under different side-play amounts iiInterior fixed area carries out average gray calculating,
The fixed area belongs to and the no more than picture of integrating sphere, and its record average gray value is L respectively0And Li；
8) being searched according to the average gray value of record makes Li=L0When critical phase-shift phase i, be recorded as i respectivelysAnd ie, then
Without the most long time of exposure of vignetting it is | is-ie| millisecond.
It is above-mentioned to implement in step, phase shift regulation is reached using waveform generator, in fact by other means
The purpose for adjusting phase shift can also be reached, such as using single chip circuit, FPGA circuitry, digital quantity programmable board, PLC system
Deng.
The present invention has following technique effect：
1st, by the equivalent realization of trigger of regulation camera in the case that the present invention does not change motor in synchrony signal sequence
Relative movement of the hot spot on switching mechanism, has reached measurement purpose.
2nd, whether the present invention has position and velocity sensor no requirement (NR) to examining system.
3rd, the present invention is a kind of method of direct measurement without the most long time of exposure of vignetting, than indirect measurement method closer in fact
Apply on border.
Description of the drawings
Fig. 1 is light path switching principle figure, and structural representation wherein a) for switching mechanism is b) plane in handoff procedure
Illustrate.
Exposure position schematic diagram when Fig. 2 is normal external trigger, wherein a) corresponding to the time of exposure is started, a) corresponding to end
The time of exposure.
Fig. 3 is camera external trigger Phase delay post-exposure position view, wherein a) corresponding to the time of exposure is started, a) right
Should be in the end time of exposure.
Composition and annexation of the Fig. 4 for measuring system.
Drawing reference numeral explanation：
1- motors；2- speculum groups；3- shaftings；4- cameras；5- launching spots；6- switching mechanisms.
Specific embodiment
As camera exposure has a certain time length, and switching mechanism has rotated to a2 positions by a1 positions within the time period,
I.e. hot spot there occurs relative motion on reflecting mirror a, as shown in Figure 2.Fig. 2 is normal external trigger exposure position schematic diagram, is being exposed
Light time internal reflector does not produce light path, therefore exposes situation without vignetting for a kind of.Fig. 3 gives believes camera external trigger
Exposure position figure after number Phase delay, when end exposure hot spot relative motion to reflecting mirror a and the boundary of through hole b
Place, is a kind of exposure situation for having vignetting.In Fig. 2, motor in synchrony signal is identical with camera exposure signal phase, and switching mechanism exists
Motor in synchrony signal goes to a1 positions when arriving just.In Fig. 3, motor in synchrony signal is switched prior to being arrived with camera exposure signal
Mechanism is ahead of a1 positions (being not drawn in figure) when motor in synchrony signal arrives.
As the above analysis, this method for changing camera external trigger signal phase realizes hot spot on switching mechanism
Relative motion, incide just reflecting mirror (or through hole) or just completely by gradually changing phase relation and can obtain hot spot
The critical moment of reflecting mirror (or through hole) has been cut out just, the difference of the two critical moments is without the most long time of exposure of vignetting.By
Reduce can the average gray of imaging when switching mechanism is formed and blocked to hot spot in the time of exposure, therefore because of phase shift
So that the moment that the gray scale of picture declines is two critical moments.
The supplementary instrument used is needed to have waveform generator and integrating sphere when being measured according to above-mentioned principle.Waveform occurs
Device should be able to provide the phase relation continuously adjustabe between all synchronizing signals needed for examining system, and each road synchronizing signal.Integration
Ball is for the cooperative target to measuring system one uniform-illumination of offer.The composition and annexation of measuring system is as shown in Figure 4.
Measuring process：
1) integrating sphere is placed in light path switched system visual field, substitute the synchronous letter of light path switched system using waveform generator
Number source, makes output level and sequential relationship and the requirement one of the light path switched system to external synchronization signal of each passage of waveform generator
Cause；
2) the camera exposure time is set for a fixed value, is made integrating sphere into visual field and without blocking, is gathered now camera figure
Picture, records the initial pictures for P0；
3) waveform generator and light path switched system are opened, the 4) step is proceeded to after path switching mechanisms spin stabilization；
4) adjust the phase place of the synchronizing signal of waveform generator connection camera channel so as to which phase deviation is in former phase place i milli
Second；
5) now camera image is gathered, it is P to record the image under side-play amount ii；
6) observe that target imaging brightness proceeds to the 7) step when substantially reducing, otherwise change i values and proceed to the 4) step；
7) the initial pictures P to recording0And the image P under different side-play amounts iiInterior fixed area carries out average gray calculating,
The fixed area belongs to and the no more than picture of integrating sphere, and its record average gray value is L respectively0And Li；
8) being searched according to the average gray value of record makes Li=L0When critical phase-shift phase i, be recorded as i respectivelysAnd ie, then
Without the most long time of exposure of vignetting it is | is-ie| millisecond.
To obtain more accurate result, a locking phase is often adjusted in such scheme and can preserve multiple image, united
Count its average gray value.The absolute value of the phase pushing figure i for adjusting every time in addition is more little, measures more accurate.
Claims (3)
1. the measuring method without the most long time of exposure of vignetting in a kind of external trigger light path switched system, it is characterised in that：
Phase relation in change camera external trigger signal and switched system between motor in synchrony signal, realizes that hot spot is cut in light path
Relative motion on converting mechanism；During gradually changing phase relation, the respective image to photographing unit output is final true respectively
Make hot spot to incide just reflecting mirror completely and just start just to cut out the critical moment of reflecting mirror, or it is final true respectively
Make hot spot to incide just through hole completely and just start to cut out the critical moment of through hole just；
During gradually changing phase relation, because of phase shift so as to be the two critical moment for declining of the gray scale of image
Moment, the difference of the two critical moments are without the most long time of exposure of vignetting.
2. the measuring method without the most long time of exposure of vignetting in external trigger light path switched system according to claim 1, its
It is characterised by：Often change a phase relation, preserve multiple image, statistical average gray value；Compared with average gray value and sentenced
Whether disconnected gray scale declines.
3. the measuring method without the most long time of exposure of vignetting in external trigger light path switched system according to claim 1 and 2,
Characterized in that, specifically including following steps：
1) integrating sphere is placed in light path switched system visual field, substitute the synchronizing signal of light path switched system using waveform generator
Source, makes output level and sequential relationship and the requirement one of the light path switched system to external synchronization signal of each passage of waveform generator
Cause；
2) the camera exposure time is set for a fixed value, is made integrating sphere into visual field and without blocking, is gathered now camera image, note
The initial pictures are recorded for P0；
3) waveform generator and light path switched system are opened, the 4) step is proceeded to after path switching mechanisms spin stabilization；
4) adjust the phase place of the synchronizing signal of waveform generator connection camera channel so as to which phase deviation is in former phase place i millisecond；
5) now camera image is gathered, it is P to record the image under side-play amount ii；
6) observe that target imaging brightness proceeds to the 7) step when substantially reducing, otherwise change i values and proceed to the 4) step；
7) the initial pictures P to recording0And the image P under different side-play amounts iiInterior fixed area carries out average gray calculating, and this is solid
Determine region to belong to and the no more than picture of integrating sphere, its record average gray value is L respectively0And Li；
8) being searched according to the average gray value of record makes Li=L0When critical phase-shift phase i, be recorded as i respectivelysAnd ie, then without vignetting
Most long time of exposure is | is-ie| millisecond.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610532919 | 2016-07-07 | ||
| CN2016105329194 | 2016-07-07 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106572282A true CN106572282A (en) | 2017-04-19 |
| CN106572282B CN106572282B (en) | 2019-05-31 |
Family
ID=58533447
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610935168.0A Active CN106572282B (en) | 2016-07-07 | 2016-11-01 | Method for measuring non-vignetting longest exposure time in external trigger light path switching system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106572282B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108445077A (en) * | 2018-01-29 | 2018-08-24 | 天津大学 | A kind of Photoelasticity test method |
| CN116600211A (en) * | 2023-06-09 | 2023-08-15 | 苏州洞悉科技有限公司 | Imaging system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080056704A1 (en) * | 2006-08-30 | 2008-03-06 | Ilia Ovsiannikov | Method, apparatus and system for dynamic range estimation of imaged scenes |
| CN101893563A (en) * | 2010-04-19 | 2010-11-24 | 清华大学 | Phase measurement method of variable exposure time imaging phase shift |
| CN101907488A (en) * | 2010-07-28 | 2010-12-08 | 中国建筑科学研究院 | Image brightness meter based on digital camera and measuring method thereof |
| CN103108125A (en) * | 2013-01-07 | 2013-05-15 | 华中科技大学 | Picture-taking synchronous control equipment of multi-camera system and method thereof |
-
2016
- 2016-11-01 CN CN201610935168.0A patent/CN106572282B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080056704A1 (en) * | 2006-08-30 | 2008-03-06 | Ilia Ovsiannikov | Method, apparatus and system for dynamic range estimation of imaged scenes |
| CN101893563A (en) * | 2010-04-19 | 2010-11-24 | 清华大学 | Phase measurement method of variable exposure time imaging phase shift |
| CN101907488A (en) * | 2010-07-28 | 2010-12-08 | 中国建筑科学研究院 | Image brightness meter based on digital camera and measuring method thereof |
| CN103108125A (en) * | 2013-01-07 | 2013-05-15 | 华中科技大学 | Picture-taking synchronous control equipment of multi-camera system and method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 高昕 等: "相位差异技术在靶场光学测量设备中的应用", 《飞行器测控学报》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108445077A (en) * | 2018-01-29 | 2018-08-24 | 天津大学 | A kind of Photoelasticity test method |
| CN108445077B (en) * | 2018-01-29 | 2022-10-14 | 天津大学 | Optical elasticity test method |
| CN116600211A (en) * | 2023-06-09 | 2023-08-15 | 苏州洞悉科技有限公司 | Imaging system |
| CN116600211B (en) * | 2023-06-09 | 2024-01-02 | 苏州洞悉科技有限公司 | Imaging system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106572282B (en) | 2019-05-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2311251B1 (en) | Rolling shutter camera system and method | |
| Cavagna et al. | The STARFLAG handbook on collective animal behaviour: Part I, empirical methods | |
| CN111736169B (en) | Data synchronization method, device and system | |
| US20170085771A1 (en) | Camera with radar system | |
| US8957956B2 (en) | Method and system for iris image capture | |
| CN103581625A (en) | Time-share parallel image collecting device and calibration method thereof | |
| CN108833795B (en) | Focusing method and device of image acquisition equipment | |
| RU2010149173A (en) | RESOLUTION OF VARIETY AND OCCLUSION OF MULTIPLE INDICATORS | |
| US20150304629A1 (en) | System and method for stereophotogrammetry | |
| CN106572282A (en) | Method for measuring non-vignetting longest exposure time in external trigger light path switching system | |
| CN104575006A (en) | Image shooting moment determining method and system as well as vehicle speed detection method and system | |
| JP2001116985A (en) | Camera with subject recognizing function and subject recognizing method | |
| JP2008152150A (en) | Imaging apparatus, its control method and program, and storage medium | |
| CN108289170A (en) | The camera arrangement and method of metering region can be detected | |
| JPS63194237A (en) | Camera | |
| CN108195291A (en) | A kind of moving vehicle 3 D detection method and detection device based on difference hot spot | |
| JPS5949525B2 (en) | Distance detection method and device | |
| KR101649181B1 (en) | Flight information estimator and estimation method of the flying objects | |
| CN106027889B (en) | Control method, control device and electronic device | |
| JP4470292B2 (en) | How to determine the photography position for photo measurement | |
| JPS60263584A (en) | Automatic tracking device in camera | |
| JPH05196857A (en) | Focus and exposure control method for camera | |
| JP2002039717A (en) | Imaging device | |
| SU933077A1 (en) | Apparatus for registering kinematic parameters of motion | |
| US2680991A (en) | Method of photography of a race |
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 |