CN106052868B

CN106052868B - Gaze-type multispectral imaging method

Info

Publication number: CN106052868B
Application number: CN201610322147.1A
Authority: CN
Inventors: 高劲松; 王笑夷; 杨飞; 张建
Original assignee: Changchun Institute of Optics Fine Mechanics and Physics of CAS
Current assignee: Changchun Changguang Chenpu Technology Co ltd
Priority date: 2016-05-16
Filing date: 2016-05-16
Publication date: 2019-02-12
Anticipated expiration: 2036-05-16
Also published as: CN106052868A

Abstract

The present invention provides a gaze-type multispectral imaging method, comprising: an optical imaging system, a dispersive element, a driving device and a detector; the optical axis of the optical imaging system is respectively perpendicular to the surface of the dispersive element and the surface of the detector. a pixel surface; the dispersive element is located between the optical imaging system and the detector; the driving device drives the dispersive element to move in one direction. By moving the dispersive element, a multispectral image under a fixed field of view can be obtained, thereby saving the production cost and reducing the structural complexity.

Description

Gazing type multispectral imaging method

Technical field

The present invention relates to light spectrum image-forming fields, in particular to a kind of gazing type multispectral imaging method.

Background technique

Spectral imaging technology has while the ability of detecting light spectrum and spatial information, is widely used in verification retrieval, food The various fields such as product examine survey, precision agriculture, resource detection, camouflage identification, biologic medical.Light spectrum image-forming mainly pushes away the type of sweeping and coagulates Depending on two kinds of imaging modes of type.Conventionally employed prism, grating are to push away the type of sweeping as the spectral imaging technology of beam splitter, and utilization is narrow Seam limitation visual field disposably projects the slit image of each wave band on detector focal plane by prism, grating dispersion.It pushes away Type light spectrum image-forming is swept to need to obtain complete data cube by the movement of platform or detection target.Therefore, itself having Push away more use on the platforms such as the satellite for sweeping movement, aircraft.Type light spectrum image-forming mode is swept in some occasions and discomfort however, pushing away With, for example system entire scan generates interference to attending physician in surgical procedure, is needed at this time using gazing type multispectral imaging System.

However, current gazing type multi-optical spectrum imaging system uses acousto-optic tunable filter (Acousto Optic Tunable Filter, AOTF) or liquid crystal tunable filter (Liquid Crystal Tunable Filter, LCTF) etc. Tunable filter part, the light spectrum image-forming wavelength band and wave band number implemented using such method are limited, and resolution ratio is lower, and tie Structure is complicated, higher cost.

Summary of the invention

It is an object of the invention to provide a kind of gazing type multispectral imaging methods, can be realized high spectral resolution and wide wave The light spectrum image-forming of segment limit.

The embodiment of the present invention provides a kind of gazing type multispectral imaging method, comprising: optical imaging system 4, dispersion element 2, driving device 3 and detector 1；The optical axis of the optical imaging system 4 be respectively perpendicular to the dispersion element 2 surface and The pixel surface of the detector 1；The dispersion element 2 is between the optical imaging system 4 and the detector 1；Institute Stating driving device 3 drives the dispersion element 2 to move in one direction.By mobile dispersion element, fixed visual field can be obtained Under multispectral image reduce structure complexity to save production cost.

Detailed description of the invention

Fig. 1 is the structural representation using the multi-optical spectrum imaging system of the gazing type multispectral imaging method of the embodiment of the present invention Figure；

Fig. 2 is the schematic diagram that the embodiment of the present invention obtains gazing type multispectral image.

Specific embodiment

With reference to the attached drawing in the embodiment of the present invention, technical solution in the embodiment of the present invention carries out clear, complete Ground description.Based on the embodiment of the present invention, those of ordinary skill in the art institute obtained under the premise of no creative work There are other embodiments, all belongs to the scope of protection of the present invention.

Fig. 1 is the structural representation using the multi-optical spectrum imaging system of the gazing type multispectral imaging method of the embodiment of the present invention Figure.As shown in Figure 1, the multi-optical spectrum imaging system specifically includes that

Optical imaging system 4, dispersion element 2, driving device 3 and detector 1.

It should be noted that dispersion element 2 and driving device 3 are properly termed as dispersion spectrophotometric unit, dispersion spectrophotometric unit can A part to be integrated in optical imaging system 4, as optical imaging system 4；It is also used as individual component, with optics Imaging system 4 is provided separately.

The optical imaging system 4 include it is all can be realized to observed object imaging optical systems, such as microscope, Camera etc..

Dispersion element 2 can for example filter for realizing the spectrum segmentation to target object, dispersion element 2 for wavelength gradual change Piece, multispectral optical filter etc..

Driving device 3 drives dispersion element 2 in the plane on pixel surface for being parallel to detector 1, along perpendicular to detection The direction of device pixel array is mobile.

Further, it should be noted that dispersion element 2 does not require consistent, 2 edge of dispersion element with the size of detection image planes The length L1 of moving direction and detector pixel array can be equal in the length L2 perpendicular to pixel array direction, can also not Deng.

The move mode of dispersion element 2 for example can be with are as follows: the left edge of dispersion element 2 is from the pixel surface of detector 1 One end enters, and removes from the other end on the pixel surface of detector 1, i.e., the left end of dispersion element 2 enters detector 1 at first Pixel array region progresses into the pixel array region of detector 1 with certain speed under the drive of driving device 3, followed by It is continuous to advance, until the right end of dispersion element 2 removes the pixel array region of detector.

Certainly, dispersion element can also be using move mode from top to bottom, as long as moving direction is perpendicular to detector picture First row or column to.

Wherein, the surface of dispersion element 2 is parallel to the focal plane of optical imaging system.

Detector 1 be used for by photoelectric effect obtain and record multispectral image information, detector 1 for example can be CCD, CMOS etc..

The pixel array received of the detector 1 passes through the spectrum of dispersion element 2, the bands of a spectrum energy after obtaining spectrum segmentation Amount.

The light being emitted from optical imaging system 4 images in the pixel surface of detector 1 by dispersion element 2, to visit The different pixel arrays for surveying device 1 obtain different spectral image informations, when entire dispersion element 2 is from the one of 1 pixel surface of detector Side enters, and when the other side removes, detector 1 is obtained with image of each bands of a spectrum under same visual field, to be consolidated Determine the multispectral image under visual field.

Image of each bands of a spectrum under same visual field is known as the complete data cube of fixed visual field, at this point, not The only information of image further includes segmenting in spectral Dimensions, can obtain the spectroscopic data of every bit on image and be appointed The image information of one spectral coverage.

It should be noted that dispersion element reverse movement can obtain the spectral image information of future time.Therefore, pass through The one-dimensional reciprocating movement of dispersion element obtains the spectroscopic data cube under different time.

It describes in detail below to the working method of multi-optical spectrum imaging system provided in an embodiment of the present invention:

Step 1, the relative position of fixed optical imaging system and detector, so that the light by optical imaging system converges Gather the focal plane in detector, to obtain clearly target object image in detector surface；

Step 2, the spectrum (λ at the different location of dispersion element surface is determined_i), which can be realized by calibration test, Specific scaling method can be with are as follows:

Spectrophotometer issues monochromatic light, impinges perpendicularly on dispersion element surface, and the spectrum for measuring hot spot irradiation position is bent Line demarcates central wavelength (λ with micrometer_i) position of corresponding hot spot point of irradiation on dispersion element.

As shown in Fig. 2, having different spectrum, that is, wavelength divisions, such as λ at the different location on dispersion element surface₀- λ_n, each spectrum width occupied by dispersion element surface is, for example, 0.05mm.

Step 3, dispersion element is placed in a plane on parallel detector pixel surface, which is located at the optics In the image planes of the imaging system or surface of adjacent locations or abutting detector.

Step 4, driving device drives dispersion element to initial position, wherein initial position is detector image planes surface Edge, if dispersion element enters from the right side of multi-optical spectrum imaging system, initial position is the right hand edge on detector image planes surface；

Step 5, movement speed needed for calculating dispersion element:

The movement speed of dispersion element can be arranged according to the calibration result of step 2 and the acquisition frame frequency of detector.

The acquisition frame frequency of detector is N, and every section of spectrum is a (mm) in the geometric widths that dispersion element occupies, then dispersion member The movement speed of part is a/ (1/N)=a*N (unit: mm/s).

For example, the acquisition frame frequency of detector is 60 (frames/s), every section of spectrum is in the geometric position that dispersion element occupies When 0.05mm, the movement speed of dispersion element is 3mm/s.

Step 6, driving device drives dispersion element to exist according to the movement speed of the dispersion beam splitter calculated in step 5 It is moved in plane between optical imaging system and detector.

Such as shown in Fig. 2, the right end of dispersion element is initially entered from the left end on the pixel surface of detector, until dispersion The left end of element removes the right end on detector pixel surface.

Step 7, the spectroscopic data of the target object of detector acquisition different moments.

As shown in Fig. 2, m₀、m₁……m_nFor the pixel position in the pixel array of detector, λ₀……λ_nFor dispersion element The corresponding different spectrum of upper different location.

In dispersion element moving process, the collected single-spectral images of different moments detector are different.

In t₀Moment, detector pixel array m₀Band 0 (0 is band serial number, is mentioned as follows similar) acquisition pair at position It should be in λ₀Spectrum, detector remove m₀Except station acquisition be full spectra image；

In t₁Moment extracts λ₀The m of corresponding detector₁Band 0 and extraction λ at position₁The m of corresponding detector₀At position Band 1；

And so on, in t_2n-1Moment extracts λ_n-1The m of corresponding detector_nBand n-1 and extraction λ at position_nIt is corresponding to visit Survey the m of device_n-1Band n at position；

In t_2nMoment extracts λ_nThe m of corresponding detector_nBand n at position；

In this way, when dispersion element removes the pixel surface of detector, by the received same light of detector difference band institute Compose λ_iImage spliced, the different spectrum pictures under fixed visual field can be obtained.

Dispersion element moves backward the spectral image information that can obtain future time.Therefore, one-dimensional by dispersion element It moves back and forth, obtains the spectroscopic data cube under different time.

The embodiment of the present invention passes through mobile dispersion member by the way that dispersion element to be placed between optical imaging system and detector Part can obtain the multispectral image under fixed visual field.Compared with conventional gazing type light spectrum image-forming mode, structure is simple, under cost Drop.

Claims

1. A gaze-type multispectral imaging method, characterized by comprising: an optical imaging system (4), a dispersive element (2), a driving device (3) and a detector (1);

The optical axis of the optical imaging system (4) is respectively perpendicular to the surface of the dispersion element (2) and the pixel surface of the detector (1);

The dispersion element (2) is a wavelength gradient filter;

The dispersive element (2) is located between the optical imaging system (4) and the detector (1);

The driving device (3) drives the dispersion element (2) to move in one direction;

The image obtained by the relative displacement of the dispersive element (2) and the detector (1) obtains multi-spectral image data by means of spectral calibration and image stitching;

The driving device to drive the dispersion element (2) to move in one direction specifically includes:

The dispersive element (2) enters from one end of the pixel surface of the detector (1) and moves out from the other end of the pixel surface of the detector (1);

The moving direction of the dispersive element (2) is perpendicular to the row or column direction of the detector (1).

2. The method according to claim 1, characterized in that before the driving device (2) drives the dispersive element (2) to move between the optical imaging system (4) and the detector (1) ,Also includes:

Different spectra at different locations on the surface of the dispersive element 2 are determined.

3. The method according to claim 2, characterized in that before the driving device (2) drives the dispersive element (2) to move between the optical imaging system (4) and the detector (1) ,Also includes:

Calculate the required moving speed of the dispersive element according to the formula a/(1/N)=a*N (unit: mm/s),

Among them, N is the acquisition frame rate of the detector, and a is the geometric width occupied by each spectrum in the dispersive element.

4. The method according to any one of claims 1 to 3, characterized in that, the dispersive element (2) is located on the image plane of the optical imaging system, or in an adjacent position, or close to the surface of the detector .

5. The method of any one of claims 1-3, wherein the optical imaging system is a camera or a microscope.