CN107197122A - A kind of method for correcting flat field being imaged for area array cameras - Google Patents
A kind of method for correcting flat field being imaged for area array cameras Download PDFInfo
- Publication number
- CN107197122A CN107197122A CN201710437027.0A CN201710437027A CN107197122A CN 107197122 A CN107197122 A CN 107197122A CN 201710437027 A CN201710437027 A CN 201710437027A CN 107197122 A CN107197122 A CN 107197122A
- Authority
- CN
- China
- Prior art keywords
- flat field
- sample
- heterogeneity
- image
- imaging
- 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.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
- H04N25/60—Noise processing, e.g. detecting, correcting, reducing or removing noise
- H04N25/63—Noise processing, e.g. detecting, correcting, reducing or removing noise applied to dark current
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Studio Devices (AREA)
Abstract
The invention discloses a kind of method for correcting flat field being imaged for area array cameras, comprise the following steps：A. bright image (white), the dark image (black) of Uniform Sample are obtained；B. the fixed pattern noise and photoresponse heterogeneity of camera sensor itself are calculated；C. according to actual imaging sample and environment, the heterogeneity of illumination imaging is obtained；D. each term coefficient of flat field correction is calculated, the image collected is corrected.Method provided by the present invention frequently need not carry out flat field correction using homogeneous sample, readily available sample can be selected to obtain the heterogeneity of illumination imaging according to field condition, scheme to obtain the fixed pattern noise and photoresponse heterogeneity coefficient of camera in combination with the white figures and black obtained in advance, easily can efficiently obtain the flat field correction coefficient of camera.
Description
Technical field
The present invention relates to a kind of bearing calibration, specifically a kind of method for correcting flat field being imaged for area array cameras.
Background technology
In existing imaging technique, imaging lens and illumination can cause the uneven of image, influence imaging results.Meanwhile,
When camera itself has fixed pattern noise or uneven photoresponse, acquired image also occurs uneven.For
The asymmetric correction method of illumination imaging only takes into account the heterogeneity of illumination and imaging, not to the fixed mode of camera itself
Noise is corrected；The complexity of trimming process is not considered for the flat field correction that the heterogeneity of camera and illumination together is done
And frequency.For example：Infrared area array cameras is widely used in Mapping remote sensing technology, night vision because its staring imaging, the advantage of high frame frequency
In all kinds of infrared imaging systems such as scouting, monitoring temperature.Due to the limitation of manufacture level at this stage, infrared area array cameras is respectively detected
The heterogeneity that generally existing is responded between member, this heterogeneity forms fixed pattern noise, have impact on the imaging of system
Quality.
The content of the invention
It is an object of the invention to provide a kind of method for correcting flat field being imaged for area array cameras, to solve above-mentioned background
The problem of being proposed in technology.
To achieve the above object, the present invention provides following technical scheme：
A kind of method for correcting flat field being imaged for area array cameras, comprises the following steps：A. the bright figure of Uniform Sample is obtained
As (white), dark image (black)；B. the fixed pattern noise and photoresponse heterogeneity of camera sensor itself are calculated；c.
According to actual imaging sample and environment, the heterogeneity of illumination imaging is obtained；D. each term coefficient of flat field correction is calculated, to collection
To image correct.
It is used as further scheme of the invention：For same camera, a, b step only need to do once, when illumination and
During imaging hair change, it is only necessary to reference to a, the result of b step completes c, and Step d is that can obtain the image result after flat field correction.
Compared with prior art, the beneficial effects of the invention are as follows：The inventive method need not frequently use homogeneous sample
To carry out flat field correction, readily available sample can be selected to obtain the heterogeneity of illumination imaging according to field condition, together
When with reference to obtain in advance white figure and black scheme obtain camera fixed pattern noise and photoresponse heterogeneity coefficient, can
Easily efficiently to obtain the flat field correction coefficient of camera.The effect of flat field correction and the school of existing method are done using this method
Plus effect quite, can be fully solved uneven by camera sensor fixed pattern noise, photoresponse heterogeneity, illumination imaging optical path
The even image quality decrease caused.
Embodiment
The technical scheme in the embodiment of the present invention is clearly and completely described below, it is clear that described embodiment
Only a part of embodiment of the invention, rather than whole embodiments.Based on the embodiment in the present invention, the common skill in this area
The every other embodiment that art personnel are obtained under the premise of creative work is not made, belongs to the model that the present invention is protected
Enclose.
In the embodiment of the present invention, a kind of method for correcting flat field being imaged for area array cameras comprises the following steps：A. obtain
Bright image (white), the dark image (black) of Uniform Sample；B. the fixed pattern noise and light of camera sensor itself are calculated
Photo-Response Non-Uniformity；C. according to actual imaging sample and environment, the heterogeneity of illumination imaging is obtained；D. flat field correction is calculated
Each term coefficient, is corrected to the image collected.
For same camera, a, b step only need to do once, when illumination and imaging hair change, it is only necessary to reference to a, b
The result of step completes c, and Step d is that can obtain the image result after flat field correction.
Correction is needed to fall the fixed pattern noise (FPN) in camera sensor, photoresponse inequality for whole imaging system
Uneven (Nonuniformity) for the light distribution that even (PRNU) and illumination and imaging are caused.
In actual treatment, PRNU and Nonuniformity are mixed, it is difficult to separated.In common correct operation
It is middle to need the very careful homogeneous sample of use to gather white and black images, then calculated according to white and black images
Flat field correction coefficient：
White=p+f
Black=p × α+f
P is the response coefficient related to light intensity, uneven comprising camera sensor Photo-Response Non-Uniformity and light distribution；f
For camera sensor fixed pattern noise；α is artwork master light intensity ratio.
Relation between true picture I and the actual image I0 obtained is represented by：
I=(I0-f) * p
P can be expressed as multiplying property coefficient K；- f*p is represented by additivity coefficient A.That is I=I0*K+A.
In order to avoid dirty on sample correction coefficient is impacted, it is necessary to when gathering white and black images it is many
It is secondary to take pictures.This is troublesome in actual use, when site environment does not allow to find extra homogeneous sample, and this method is very not yet
It is convenient, not even with operability.Meanwhile, it is former due to illuminating the difference of imagewise uniform after optical system is debugged or is changed
Some coefficients may be no longer applicable.These are required for a set of simple and feasible method to produce correction coefficient.
In theory, for single camera, PRNU and FPN are changeless, and the uniformity illuminated can be according to illumination
Change with imaging optical path, sample etc. and occur corresponding change.Therefore, only need to be done according to illumination change in theory
Nonuniformity processing, combining camera PRNU itself and FPN can just generate suitable correction coefficient.In FPD face
In plate detection, Nonuniformity is handled and additionally need not carried out using homogeneous sample, directly using panel detection
Pattern glass is just enough to calculate the coefficient of needs, will so mitigate workload significantly.By Nonuniformity and PRNU,
FPN is separately theoretical feasible and is necessary.
Relation between true picture I and the actual image I0 obtained can be expressed as with second method：
I=I0*prnu/nonuniformity+A
The method that Nonuniformity is separated with PRNU/FPN is based on the assumption that and method：
1, PRNU is Pixel-level coefficient as FPN, and Nonuniformity is region property coefficient.
2, K0, A0 are measured by white and black first for camera, then calculated by white figures
Nonuniformity0, prnu is calculated with this, is preserved prnu and A0 as camera configuration file, is completed a, b step
3, in actual use according to sample and the difference of illumination, corresponding nonuniformity is measured, step c is completed.
Actual K, A can be then calculated, Step d is completed.
Correlation formula has：
Nonuniformity0=uniformity (white-A0)
Prnu=K0*nonuniformity0
K=prnu/nonuniformity
A=A0
Equation below can be used to carry out flat field correction for the image of collection
I=I0*K+A
By taking the application on panel display board detection device as an example, specific implementation process of the invention is as follows：
1, homogeneous flat sample acquisition solid white image (white) is used under a certain optical imaging system, brightness is to reach
The 4/5 of camera gray scale depth is advisable.In order to eliminate dirty on sample, it is necessary to multiple dynamic acquisition, while ensureing the exposure of camera
Between light time, gain etc. sets constant.
2, illumination intensity is adjusted, the homogeneous flat sample acquisition pure black image is used under the optical imaging system
(black), brightness is advisable with reach camera gray scale depth 1/10.It is dirty, it is necessary to which repeatedly dynamic is adopted on sample in order to eliminate
Collection, while ensureing the time for exposure of camera, gain etc. sets constant.
3, schemed according to acquired white figures and black, according to formula calculate camera the COEFFICIENT K 0 related to PRNU and
The coefficient A0 related to FPN, formula is as follows：
White=p+f
Black=p × α+f
Obtain：
K0=mean (p)/p
A0=-f*mean (p)/p
4, schemed according to white, calculate the illumination imaging distributing homogeneity nonuniformity0 under the imaging system,
Calculation formula is：
Nonuniformity0=uniformity (white-A0)
The prnu coefficients of camera are calculated, method is as follows：
Prnu=K0*nonuniformity0
5, at panel detection scene, choosing can be carried out on panel full of the region being evenly distributed of whole imaging viewing field
Picture, obtains its image conformity, is the heterogeneity nonuniformity of live light distribution.
6, according to equation below, calculate the flat field correction coefficient under field condition：
K=prnu/nonuniformity
A=A0
Flat field correction is carried out according to the formula I=I0*K+A image I0 arrived to live actual acquisition.It can obtain flat field correction
Uniform, high quality graphic afterwards.
It is obvious to a person skilled in the art that the invention is not restricted to the details of above-mentioned one exemplary embodiment, Er Qie
In the case of without departing substantially from spirit or essential attributes of the invention, the present invention can be realized in other specific forms.Therefore, no matter
From the point of view of which point, embodiment all should be regarded as exemplary, and be nonrestrictive, the scope of the present invention is by appended power
Profit is required rather than described above is limited, it is intended that all in the implication and scope of the equivalency of claim by falling
Change is included in the present invention.Although not each moreover, it will be appreciated that the present specification is described in terms of embodiments
Embodiment is only comprising an independent technical scheme, and this narrating mode of specification is only this area for clarity
Technical staff should be using specification as an entirety, and the technical solutions in the various embodiments may also be suitably combined, forms this
Art personnel may be appreciated other embodiment.
Claims (2)
1. a kind of method for correcting flat field being imaged for area array cameras, it is characterised in that comprise the following steps：A. uniform sample is obtained
This bright image (white), dark image (black)；B. fixed pattern noise and the photoresponse for calculating camera sensor itself are non-
Uniformity；C. according to actual imaging sample and environment, the heterogeneity of illumination imaging is obtained；D. each term system of flat field correction is calculated
Number, is corrected to the image collected.
2. the method for correcting flat field according to claim 1 being imaged for area array cameras, it is characterised in that for same
Camera, a, b step only need to do once, when illumination and imaging hair change, it is only necessary to which, with reference to a, the result of b step completes c, d
Step is that can obtain the image result after flat field correction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710437027.0A CN107197122A (en) | 2017-06-12 | 2017-06-12 | A kind of method for correcting flat field being imaged for area array cameras |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710437027.0A CN107197122A (en) | 2017-06-12 | 2017-06-12 | A kind of method for correcting flat field being imaged for area array cameras |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107197122A true CN107197122A (en) | 2017-09-22 |
Family
ID=59877356
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710437027.0A Pending CN107197122A (en) | 2017-06-12 | 2017-06-12 | A kind of method for correcting flat field being imaged for area array cameras |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107197122A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107770410A (en) * | 2017-10-16 | 2018-03-06 | 深圳市中瑞微视光电有限公司 | The adaptive corrective of colored area array CCD |
| CN107835337A (en) * | 2017-10-11 | 2018-03-23 | 北京中科慧眼科技有限公司 | Black and white area array CCD camera method for correcting flat field and system |
| CN108562541A (en) * | 2018-04-23 | 2018-09-21 | 南京大学 | Based on matrix decomposition without lens holographic microphotography speckle noise minimizing technology and device |
| CN108986170A (en) * | 2018-07-03 | 2018-12-11 | 武汉精测电子集团股份有限公司 | A kind of line-scan digital camera method for correcting flat field suitable for field working conditions |
| WO2019183759A1 (en) * | 2018-03-26 | 2019-10-03 | 深圳市大疆创新科技有限公司 | Image fusion method, image capturing apparatus, and mobile platform system |
| CN113822940A (en) * | 2021-08-27 | 2021-12-21 | 华兴源创(成都)科技有限公司 | Flat field correction calibration method, device and system, computer equipment and medium |
| CN115760653A (en) * | 2023-01-09 | 2023-03-07 | 武汉中导光电设备有限公司 | Image correction method, device, equipment and readable storage medium |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102508144A (en) * | 2011-10-26 | 2012-06-20 | 西安电子科技大学 | Method for measuring dark signal non-uniformity and photon response non-uniformity of photons of CCD (charge coupled device) chip |
| CN102663732A (en) * | 2012-03-14 | 2012-09-12 | 中国科学院光电研究院 | Relative radiometric calibration method for light field camera |
| CN102819831A (en) * | 2012-08-16 | 2012-12-12 | 江南大学 | Camera source evidence obtaining method based on mode noise big component |
-
2017
- 2017-06-12 CN CN201710437027.0A patent/CN107197122A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102508144A (en) * | 2011-10-26 | 2012-06-20 | 西安电子科技大学 | Method for measuring dark signal non-uniformity and photon response non-uniformity of photons of CCD (charge coupled device) chip |
| CN102663732A (en) * | 2012-03-14 | 2012-09-12 | 中国科学院光电研究院 | Relative radiometric calibration method for light field camera |
| CN102819831A (en) * | 2012-08-16 | 2012-12-12 | 江南大学 | Camera source evidence obtaining method based on mode noise big component |
Non-Patent Citations (5)
| Title |
|---|
| 修吉宏: "大面阵彩色CCD航测相机成像非均匀性校正", 《光学学报》 * |
| 刘妍妍: "可见光面阵CCD响应非均匀性的检测与校正", 《液晶与显示》 * |
| 李华: "面阵CCD图像传感器不均匀性的校正", 《传感器技术》 * |
| 王钰: "实时红外图像非均匀性校正技术研究", 《激光与红外》 * |
| 董建婷: "面阵CMOS图像传感器性能测试及图像处理", 《红外与激光工程》 * |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107835337A (en) * | 2017-10-11 | 2018-03-23 | 北京中科慧眼科技有限公司 | Black and white area array CCD camera method for correcting flat field and system |
| CN107770410A (en) * | 2017-10-16 | 2018-03-06 | 深圳市中瑞微视光电有限公司 | The adaptive corrective of colored area array CCD |
| WO2019183759A1 (en) * | 2018-03-26 | 2019-10-03 | 深圳市大疆创新科技有限公司 | Image fusion method, image capturing apparatus, and mobile platform system |
| CN110622496A (en) * | 2018-03-26 | 2019-12-27 | 深圳市大疆创新科技有限公司 | Image fusion method, shooting device and movable platform system |
| US11425316B2 (en) | 2018-03-26 | 2022-08-23 | SZ DJI Technology Co., Ltd. | Image fusion method, image capturing apparatus, and mobile platform system |
| CN108562541A (en) * | 2018-04-23 | 2018-09-21 | 南京大学 | Based on matrix decomposition without lens holographic microphotography speckle noise minimizing technology and device |
| CN108986170A (en) * | 2018-07-03 | 2018-12-11 | 武汉精测电子集团股份有限公司 | A kind of line-scan digital camera method for correcting flat field suitable for field working conditions |
| CN108986170B (en) * | 2018-07-03 | 2020-11-06 | 武汉精测电子集团股份有限公司 | Linear array camera flat field correction method suitable for field working conditions |
| CN113822940A (en) * | 2021-08-27 | 2021-12-21 | 华兴源创(成都)科技有限公司 | Flat field correction calibration method, device and system, computer equipment and medium |
| CN113822940B (en) * | 2021-08-27 | 2023-09-01 | 华兴源创(成都)科技有限公司 | Flat field correction calibration method, device and system, computer equipment and medium |
| CN115760653A (en) * | 2023-01-09 | 2023-03-07 | 武汉中导光电设备有限公司 | Image correction method, device, equipment and readable storage medium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107197122A (en) | A kind of method for correcting flat field being imaged for area array cameras | |
| CN109478394A (en) | Display correction device, program and display correction system | |
| CN101674443B (en) | Method for correcting colors of projector | |
| CN103297789B (en) | White balance correcting method and white balance correcting device | |
| JPH0284888A (en) | Optical image processing method and system for x-ray photographing | |
| WO2008148291A1 (en) | Device and method for calibrating multi-screen wall | |
| CN108871588A (en) | A kind of infrared imaging system various dimensions joint asymmetric correction method | |
| US9800868B2 (en) | Image-sticking inspection method for liquid crystal panel and device of the same | |
| CN103546730A (en) | Method for enhancing light sensitivities of images on basis of multiple cameras | |
| US10771709B2 (en) | Evaluation device, evaluation method, and camera system | |
| CN107144239A (en) | A kind of Gain Automatic adjusting method of handheld structure light spatial digitizer | |
| US20150356896A1 (en) | Apparatus and method for image analysis and image display | |
| CN103312983B (en) | A kind of terahertz imaging instrument lens compensation method | |
| CN108010071B (en) | System and method for measuring brightness distribution by using 3D depth measurement | |
| CN113870355A (en) | Flat field calibration method, flat field calibration device and flat field calibration system of camera | |
| CN101187756B (en) | Display, display circuit and processing method for obtaining high dynamic range image | |
| CN108088365B (en) | Digital micromirror camera coordinate accurate mapping method based on phase | |
| CN111383280A (en) | Spatial remote sensing TDICCD camera non-uniformity correction method and device | |
| US6710321B2 (en) | Display image quality measuring system | |
| US8218034B2 (en) | Method for automatically correcting frame faults in video assist frames of a video assist system | |
| JP5609459B2 (en) | Binarization processing method and image processing apparatus | |
| CN110361165B (en) | Manufacturing method for liquid crystal screen blue light component detection and analysis equipment and equipment manufactured by same | |
| CN111479097B (en) | Scattering lens imaging system based on deep learning | |
| CN115002360A (en) | Infrared video non-uniformity correction method based on robust estimation | |
| JPH08254499A (en) | Displaying/appearance inspection device |
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 | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20170922 |
|
| RJ01 | Rejection of invention patent application after publication |