CN104267407A - Initiative imaging method and system based on compressed sampling - Google Patents

Abstract

The invention relates to the field of initiative imaging, and provides an initiative imaging system based on compressed sampling. The initiative imaging system comprises a pulsed light signal generating device used for generating pulsed light signals, a light imaging device used for imaging the pulsed light signals generated by the pulsed light signal generating device, a light collecting device used for collecting reflected light formed by a pulsed light signal irradiation target scene processed by the light imaging device, a first light modulator used for carrying out first spectrum modulation on the reflected light collected by the light collecting device, and an image reconstructing device used for carrying out image reconstruction on the pulsed light signals modulated by the first light modulator. According to the initiative imaging system, a digital micromirror array and other mechanical structures in a traditional single-pixel imaging system are removed, and the imaging speed is greatly increased.

Description

Based on the Active Imaging method and system of compression sampling

Technical field

The present invention relates to Active Imaging field, particularly, relate to the Active Imaging method and apparatus based on compression sampling.

Background technology

In imaging systems, according to or without lighting source, Active Imaging and imaging and passive imaging two kinds of imaging modes are divided into.The maximum feature of imaging and passive imaging is that itself is not with light source, relies on natural light or target self radiation such as target or the Ambient sun, uses imaging device to detect these feeble signals and final imaging.Active Imaging refers to and utilizes artificially lighting mode, adopts an artificial optical radiation source to irradiate target, and utilizes receiver to collect and the also last imaging of the partial radiation of detection of a target scenery directly or after reflection.Due to laser have high strength, high collimation, monochromaticity good, be easy to the advantage such as synchronous, in active imaging system, thus usually adopt laser instrument as lighting source to irradiate target, exploring laser light pulse echo signal, obtain the high-definition picture of target.Utilize Laser active illuminated imaging technology to combine with advanced image processing techniques the detection of a target, under zero illumination conditions, target detection can be carried out at any time in be concerned about region.

Compression sampling technology is a kind of novel Signal Collection Technology, and its essence gathers useful information and abandons garbage, makes the collecting efficiency of signal higher, overcomes the restriction of Nyquist law, and signal sampling and signal compression are carried out simultaneously.Single pixel imaging is the important application of compression sampling technology in imaging field, utilize compression sampling principle, only need the detector of single pixel just can realize the acquisition of entire image, greatly reduce storage and the transmitted data amount of image, improve imaging dirigibility.The basic structure of the single pixel imaging of tradition comprises optical lens, digital micromirror array (DMD) and single pixel detector etc.Utilize optical lens that imaging beam is mapped on digital micromirror array, adjusted by the eyeglass of digital micromirror array, obtain random measurement matrix.And then the light of digital micromirror array reflection is focused in focus by an optical lens again, place the detection that a single pixel detector carries out signal in focal position, form an image measurement.Through repeatedly such measuring process, obtain enough data, then carry out the recovery of image by corresponding compression sampling algorithm.Usual pendulous frequency is the recovery that 20% of image slices vegetarian refreshments just can realize most of image.It can thus be appreciated that, adopt single pixel imaging system of compression sampling the data volume of image can be reduced an order of magnitude, and compression and sampling two processes are combined, simplify imaging system.But, this method has a very large defect, that is exactly digital micromirror array normally micro mechanical structure or liquid-crystal apparatus, this makes micro mirror array speed when adjustment stochastic matrix excessively slow, image taking speed reduces greatly, is no more than 100 frames/second, and this makes single pixel imaging system can only be used for taking static or accurate static image, and high speed image and video can not be obtained, seriously limit the range of application of single pixel imaging.

Summary of the invention

In order to solve the problems referred to above that prior art exists, the invention provides a kind of formation method of the active imaging system based on compression sampling, comprising: use pulse optical signal generating device to produce pulsed optical signals; The pulsed optical signals produced by described pulse optical signal generating device carries out the first spectral modulation; Pulsed optical signals after the first spectral modulation is input to photoimaging equipment; The pulsed optical signals exported from described photoimaging equipment is used to irradiate target scene; Optical acquisition device is used to gather the reflected light of described target scene; Image Reconstruction device is used to carry out Image Reconstruction to described reflected light.

Alternatively, the step that the described pulsed optical signals produced by described pulse optical signal generating device carries out the first spectral modulation comprises: the resolution according to the image expected produces pseudo-random code; By pscudo-random codc modulation to pulsed optical signals spectrally.

Alternatively, the pixel number of the image of described expectation is N, then described pseudo-random code comprises the sequence of M, and each described sequence comprises N number of chip.

Alternatively, M is the 20%-40% of N.

Alternatively, the described pulsed optical signals produced by described pulse optical signal generating device also comprises: launched in time domain by the frequency spectrum of described pulsed optical signals before carrying out the step of the first spectral modulation.

Alternatively, described pulse optical signal generating device comprises: have the light source that pulse exports.

Alternatively, described pulse optical signal generating device comprises: ultrashort light pulse source.

Alternatively, described photoimaging equipment comprises: scattered grating and the first lens; Described step pulsed optical signals after the first spectral modulation being input to photoimaging equipment comprises: the pulsed optical signals after modulation is input to the scattering that scattered grating carries out spectrum; Pulsed optical signals after scattering is focused on by the first lens.

Alternatively, described photoimaging equipment also comprises: polarization adjusting device; Described step pulsed optical signals after the first spectral modulation being input to photoimaging equipment comprises: the pulsed optical signals after modulation is input to polarization adjusting device and carries out polarization adjustment; Pulsed optical signals after carrying out polarization adjustment is input to the scattering that scattered grating carries out spectrum; Pulsed optical signals after scattering is focused on by the first lens.

Alternatively, described photoimaging equipment comprises: the first lens; The step that the pulsed optical signals exported from described photoimaging equipment irradiates target scene is used to comprise: described target scene is placed on the focus of described first lens; The pulsed optical signals appeared from described first lens is used to irradiate described target scene.

Alternatively, described optical acquisition device comprises: the second lens; The step using optical acquisition device to gather the reflected light of described target scene comprises: described second lens are placed on a fixed position, and in this fixed position, described target scene is the focal length of described second lens to the distance of described second lens.

Alternatively, Image Reconstruction device is used to comprise the step that described reflected light carries out Image Reconstruction: to carry out single pixel compression to the pulsed optical signals collected; Convert the light signal after single pixel compression to electric signal; Image Reconstruction is carried out to described electric signal.

Alternatively, the step that the described pulsed optical signals produced by described pulse optical signal generating device carries out the first spectral modulation comprises: the resolution according to the image expected produces pseudo-random code; By pscudo-random codc modulation to pulsed optical signals spectrally; The step of described electric signal being carried out to Image Reconstruction comprises: use described pseudo-random code to carry out Image Reconstruction to described electric signal.

Alternatively, the step that the pulsed optical signals collected carries out single pixel compression is also comprised: the described pulsed optical signals collected is compressed in time domain; Described pseudo-random code is used to carry out single pixel compression to the pulsed optical signals after compression.

Alternatively, described imaging system comprises: the first Dispersive Devices; Described Image Reconstruction device comprises: the second Dispersive Devices; The described pulsed optical signals produced by described pulse optical signal generating device also comprises before carrying out the step of the first spectral modulation: use described first Dispersive Devices to be launched in time domain by the frequency spectrum of described pulsed optical signals; The step of the pulsed optical signals collected being carried out to single pixel compression comprises: use the second Dispersive Devices to compress in time domain the described pulsed optical signals collected; The described pseudo-random code be modulated on described pulsed optical signals is used in described first spectral modulation to carry out single pixel compression to the pulsed optical signals after compression; The dispersion values of described first Dispersive Devices is D1, and the dispersion values of described second device is D2, D1=-D2.

Alternatively, described pulse optical signal generating device comprises: optical signal generator, the second pattern generator and the second photomodulator; Described use pulse optical signal generating device produces the step of pulsed optical signals, comprising: described optical signal generator produces the light signal that no pulse exports, and is input to the second photomodulator; Described second pattern generator produces pulse signal, and is input to described second photomodulator; Described second photomodulator by described pulse signal modulation on described light signal.

Alternatively, the pulse signal that described second pattern generator produces produces according to the spectral width of imaging rate and described optical signal generator.

Alternatively, described imaging system comprises: the first pattern generator; The step that the described pulsed optical signals produced by described pulse optical signal generating device carries out the first spectral modulation comprises: use the first pattern generator to produce pseudo-random code; By pscudo-random codc modulation to pulsed optical signals spectrally; The clock signal synchronization of described first pattern generator and described second pattern generator.

Alternatively, described imaging system also comprises, clock source; Described clock source produces synchronizing clock signals, is input to the first waveform or pattern generator and the second waveform or pattern generator.

Alternatively, described optical signal generator comprises: noncoherent broadband light source.

According to another aspect of the present invention, additionally provide a kind of formation method of the active imaging system based on compression sampling, comprising: use pulse optical signal generating device to produce pulsed optical signals; The pulsed optical signals that described pulse optical signal generating device produces is input to photoimaging equipment; The pulsed optical signals exported from described photoimaging equipment is used to irradiate target scene; Optical acquisition device is used to gather the reflected light of described target scene; First spectral modulation is carried out to the reflected light that described optical acquisition device gathers; Use Image Reconstruction device that the pulsed optical signals after the first spectral modulation is carried out Image Reconstruction.

Alternatively, the step that the described reflected light gathered described optical acquisition device carries out the first spectral modulation comprises: the resolution according to the image expected produces pseudo-random code; By pscudo-random codc modulation to reflected light pulsed optical signals spectrally.

Alternatively, the pixel number of the image of described expectation is N, then described pseudo-random code comprises the sequence of M, and each described sequence comprises N number of chip.

Alternatively, M is the 20%-40% of N.

Alternatively, the described reflected light gathered described light signal acquisition device also comprises: launched in time domain by the frequency spectrum of the pulsed optical signals of described reflected light before carrying out the step of the first spectral modulation.

Alternatively, described pulse optical signal generating device comprises: have the light source that pulse exports.

Alternatively, described pulse optical signal generating device comprises: ultrashort light pulse source.

Alternatively, described photoimaging equipment comprises: scattered grating and the first lens; The described step pulsed optical signals that described pulse optical signal generating device produces being input to photoimaging equipment comprises: pulsed optical signals is input to the scattering that scattered grating carries out spectrum; Pulsed optical signals after scattering is focused on by the first lens.

Alternatively, described photoimaging equipment also comprises: polarization adjusting device; The described step pulsed optical signals that described pulse optical signal generating device produces being input to photoimaging equipment comprises: the pulsed optical signals after modulation is input to polarization adjusting device and carries out polarization adjustment; Pulsed optical signals after carrying out polarization adjustment is input to the scattering that scattered grating carries out spectrum; Pulsed optical signals after scattering is focused on by the first lens.

Alternatively, described photoimaging equipment comprises: the first lens; The step that the pulsed optical signals exported from described photoimaging equipment irradiates target scene is used to comprise: described target scene is placed on the focus of described first lens; The pulsed optical signals appeared from described first lens is used to irradiate described target scene.

Alternatively, described optical acquisition device comprises: the second lens; The step using optical acquisition device to gather the reflected light of described target scene comprises: described second lens are placed on a fixed position, and in this fixed position, described target scene is the focal length of described second lens to the distance of described second lens.

Alternatively, Image Reconstruction device is used to comprise the step that the pulsed optical signals after the first spectral modulation carries out Image Reconstruction: to carry out single pixel compression to the pulsed optical signals after the first spectral modulation; Convert the light signal after single pixel compression to electric signal; Image Reconstruction is carried out to described electric signal.

Alternatively, the step that the described reflected light gathered described optical acquisition device carries out the first spectral modulation comprises: the resolution according to the image expected produces pseudo-random code; By pscudo-random codc modulation to reflected light pulsed optical signals spectrally; The step of described electric signal being carried out to Image Reconstruction comprises: use described pseudo-random code to carry out Image Reconstruction to described electric signal.

Alternatively, the step that the pulsed optical signals after the first spectral modulation carries out single pixel compression is also comprised: described pulsed optical signals after the first spectral modulation is compressed in time domain; Described pseudo-random code is used to carry out single pixel compression to the pulsed optical signals after compression.

Alternatively, described imaging system comprises: the first Dispersive Devices; Described Image Reconstruction device comprises: the second Dispersive Devices; The described reflected light gathered described optical acquisition device also comprises before carrying out the step of the first spectral modulation: use described first Dispersive Devices to be launched in time domain by the frequency spectrum of the pulsed optical signals of described reflected light; The step of the pulsed optical signals after the first spectral modulation being carried out to single pixel compression comprises: use the second Dispersive Devices to compress in time domain described pulsed optical signals after the first spectral modulation; The pseudo-random code in described first spectral modulation is used to carry out single pixel compression to the pulsed optical signals after compression; The dispersion values of described first Dispersive Devices is D1, and the dispersion values of described second device is D2, D1=-D2.

Alternatively, described pulse optical signal generating device comprises: optical signal generator, the second pattern generator and the second photomodulator; Described use pulse optical signal generating device produces the step of pulsed optical signals, comprising: described optical signal generator produces the light signal that no pulse exports, and is input to the second photomodulator; Described second pattern generator produces pulse signal, and is input to described second photomodulator; Described second photomodulator by described pulse signal modulation on described light signal.

Alternatively, the pulse signal that described second pattern generator produces produces according to the spectral width of imaging rate and described optical signal generator.

Alternatively, described imaging system comprises: the first pattern generator; The step that the described reflected light to optical acquisition device collection carries out the first spectral modulation comprises: use the first pattern generator to produce pseudo-random code; By pscudo-random codc modulation to described reflected light pulsed optical signals spectrally; The clock signal synchronization of described first pattern generator and described second pattern generator.

Alternatively, described imaging system also comprises, clock source; Described clock source produces synchronizing clock signals, is input to the first pattern generator and the second pattern generator.

Alternatively, described optical signal generator comprises: noncoherent broadband light source.

According to another aspect of the invention, additionally provide a kind of active imaging system based on compression sampling, comprising: pulse optical signal generating device, for generation of pulsed optical signals; First photomodulator, carries out the first spectral modulation for the pulsed optical signals produced described pulse optical signal generating device; Photoimaging equipment, for carrying out imaging to the pulsed optical signals after the first light modulator modulates; Optical acquisition device, the reflected light formed for irradiating target scene to the pulsed optical signals after photoimaging equipment process gathers; Image Reconstruction device, carries out Image Reconstruction for the reflected light collected described optical acquisition device.

Alternatively, described imaging system also comprises: the first pattern generator, produces pseudo-random code, and be input in described first photomodulator by the described pseudo-random code produced for the resolution according to the image expected; Described first photomodulator by described pscudo-random codc modulation on described pulsed optical signals.

Alternatively, the pixel number of the image of described expectation is N, then the pseudo-random code that described first pattern generator produces comprises M sequence, and each described sequence comprises N number of chip.

Alternatively, M is the 20%-40% of N.

Alternatively, described imaging system also comprises: the first Dispersive Devices; Described first Dispersive Devices is for launching the frequency spectrum of described pulsed optical signals in time domain; Described first photomodulator by described pscudo-random codc modulation on the pulsed optical signals after the first Dispersive Devices process.

Alternatively, described pulse optical signal generating device comprises: have the light source that pulse exports.

Alternatively, described pulse optical signal generating device comprises: ultrashort light pulse source.

Alternatively, described photoimaging equipment comprises: scattered grating and the first lens; Described scattered grating is used for the spectrum of pulsed optical signals to carry out scattering; Described first lens are used for the spectrum after scattering to focus on.

Alternatively, described photoimaging equipment also comprises: polarization adjusting device; Described polarization adjusting device is used for pulsed optical signals to carry out polarization adjustment; The spectrum that described scattered grating is used for the pulsed optical signals after being adjusted by polarization carries out scattering; Described first lens are used for the spectrum after scattering to focus on.

Alternatively, the described target scene of pre-imaging is placed on the focus place of described first lens; The pulsed optical signals appeared from described first lens is used to irradiate described target scene.

Alternatively, described optical acquisition device comprises: the second lens; Described second lens are positioned at a fixed position, and in this fixed position, described target scene is the focal length of described second lens to the distance of described second lens.

Alternatively, described Image Reconstruction device comprises: photoelectric commutator, for converting the pulsed optical signals of the reflected light collected to electric signal; Processor, for carrying out computing to electric signal; Display, for showing the image after reconstruct.

Alternatively, described Image Reconstruction device also comprises: the second Dispersive Devices; Described second Dispersive Devices is for compressing in time domain the pulsed optical signals of described reflected light.

Alternatively, described imaging system also comprises: the first Dispersive Devices; Described first Dispersive Devices is for launching the frequency spectrum of described pulsed optical signals in time domain; Described first photomodulator by described pscudo-random codc modulation on the pulsed optical signals after the first Dispersive Devices process; The dispersion values of described first Dispersive Devices is D1, and the dispersion values of described second device is D2, D1=-D2.

Alternatively, described imaging system also comprises: the first pattern generator, produces pseudo-random code, and be input in described first photomodulator by the described pseudo-random code produced for the resolution according to the image expected; Described first photomodulator by described pscudo-random codc modulation on described pulsed optical signals; The pseudo-random code that described processor uses the first pattern generator to produce carries out single pixel compression to the electric signal after conversion.

Alternatively, described pulse optical signal generating device comprises: optical signal generator, the second pattern generator, the second photomodulator; The light signal that described optical signal generator exports for generation of no pulse; Described second pattern generator is for generation of pulse signal; The light signal that described second photomodulator produces to described optical signal generator for the pulse signal modulation produced by described second pattern generator.

Alternatively, described optical signal generator comprises: noncoherent broadband light source.

Alternatively, described second pattern generator produces pulse signal according to the spectral width of imaging rate and described optical signal generator.

Alternatively, described imaging system also comprises: the first pattern generator, produces pseudo-random code, and be input in described first photomodulator by the described pseudo-random code produced for the resolution according to the image expected; Described first photomodulator by described pscudo-random codc modulation on described pulsed optical signals; The reference clock synchronization of described first pattern generator and described second pattern generator.

Alternatively, described system also comprises: clock source; Described clock source produces synchronizing clock signals, is input in the first pattern generator and the second pattern generator.

According to a further aspect of the invention, additionally provide a kind of active imaging system based on compression sampling, comprising: pulse optical signal generating device, for generation of pulsed optical signals; Photoimaging equipment, carries out imaging for the pulsed optical signals produced described pulse optical signal generating device; Optical acquisition device, the reflected light formed for irradiating target scene to the pulsed optical signals after photoimaging equipment process gathers; First photomodulator, carries out the first spectral modulation for the reflected light collected described optical acquisition device; Image Reconstruction device, for carrying out Image Reconstruction to the pulsed optical signals after the first light modulator modulates.

Alternatively, described imaging system also comprises: the first pattern generator, produces pseudo-random code, and be input in described first photomodulator by the described pseudo-random code produced for the resolution according to the image expected; On the pulsed optical signals of the reflected light that described pscudo-random codc modulation gathers to described optical acquisition device by described first photomodulator.

Alternatively, the pixel number of the image of described expectation is N, then the pseudo-random code that described first pattern generator produces comprises M sequence, and each described sequence comprises N number of chip.

Alternatively, M is the 20%-40% of N.

Alternatively, described imaging system also comprises: the first Dispersive Devices; Described first Dispersive Devices launches in time domain for the frequency spectrum of the pulsed optical signals by described reflected light; Described first photomodulator by described pscudo-random codc modulation on the pulsed optical signals after the first Dispersive Devices process.

Alternatively, described pulse optical signal generating device comprises: have the light source that pulse exports.

Alternatively, described pulse optical signal generating device comprises: ultrashort light pulse source.

Alternatively, described photoimaging equipment comprises: scattered grating and the first lens; The spectrum that described scattered grating is used for the pulsed optical signals produced by described pulse optical signal generating device carries out scattering; Described first lens are used for the spectrum after scattering to focus on.

Alternatively, described photoimaging equipment also comprises: polarization adjusting device; Described polarization adjusting device is used for pulsed optical signals to carry out polarization adjustment; The spectrum that described scattered grating is used for the pulsed optical signals after being adjusted by polarization carries out scattering; Described first lens are used for the spectrum after scattering to focus on.

Alternatively, the described target scene of pre-imaging is placed on the focus place of described first lens; The pulsed optical signals appeared from described first lens is used to irradiate described target scene.

Alternatively, described optical acquisition device comprises: the second lens; Described second lens are positioned at a fixed position, and in this fixed position, described target scene is the focal length of described second lens to the distance of described second lens.

Alternatively, described Image Reconstruction device comprises: photoelectric commutator, for converting the pulsed optical signals through the first optical spectral modulator modulation to electric signal; Processor, for carrying out computing to electric signal; Display, for showing the image after reconstruct.

Alternatively, described Image Reconstruction device also comprises: the second Dispersive Devices; Described second Dispersive Devices is for compressing in time domain the described pulsed optical signals through the first optical spectral modulator modulation.

Alternatively, described imaging system also comprises: the first Dispersive Devices; Described first Dispersive Devices launches in time domain for the frequency spectrum of the pulsed optical signals produced by described pulsed optical signals generator; Described first photomodulator by described pscudo-random codc modulation on the pulsed optical signals after the first Dispersive Devices process; The dispersion values of described first Dispersive Devices is D1, and the dispersion values of described second device is D2, D1=-D2.

Alternatively, described imaging system also comprises: the first pattern generator, produces pseudo-random code, and be input in described first photomodulator by the described pseudo-random code produced for the resolution according to the image expected; Described first photomodulator by described pscudo-random codc modulation on the pulsed optical signals of described reflected light; The pseudo-random code that described processor uses the first pattern generator to produce carries out single pixel compression to the electric signal after conversion.

Alternatively, described pulse optical signal generating device comprises: optical signal generator, the second pattern generator, the second photomodulator; The light signal that described optical signal generator exports for generation of no pulse; Described second pattern generator is for generation of pulse signal; The light signal that described second photomodulator produces to described optical signal generator for the pulse signal modulation produced by described second pattern generator.

Alternatively, described optical signal generator comprises: noncoherent broadband light source.

Alternatively, described second pattern generator produces pulse signal according to the spectral width of imaging rate and described optical signal generator.

Alternatively, described imaging system also comprises: the first pattern generator, produces pseudo-random code, and be input in described first photomodulator by the described pseudo-random code produced for the resolution according to the image expected; Described first photomodulator by described pscudo-random codc modulation on the pulsed optical signals of described reflected light; The reference clock synchronization of described first pattern generator and described second pattern generator.

Alternatively, described system also comprises: clock source; Described clock source produces synchronizing clock signals, is input in the first pattern generator and the second pattern generator.

Active Imaging method based on compression sampling of the present invention, light signal time domain superposes random signal, high speed optoelectronic modulator is utilized to apply time domain measurement at a high speed, and utilize Dispersive Devices to carry out area of light squeeze operation, whole processing procedure make use of photoelectric effect or physical influence, do not need mechanical adjust structure, avoid the physical constructions such as the digital micromirror array in the middle of traditional single pixel imaging system, substantially increase image taking speed.

Accompanying drawing explanation

Fig. 1 a is the imaging system Organization Chart of embodiment one;

Fig. 1 b is the imaging system Organization Chart of embodiment one;

Fig. 2 a is the imaging system Organization Chart of embodiment two;

Fig. 2 b is the imaging system Organization Chart of embodiment two;

Fig. 3 a is the imaging system Organization Chart of embodiment three;

Fig. 3 b is the imaging system Organization Chart of embodiment three;

Fig. 4 a is the imaging system Organization Chart of embodiment four;

Fig. 4 b is the imaging system Organization Chart of embodiment four.

Embodiment

Embodiments provide the Active Imaging method and apparatus based on compression sampling, change and adopt digital micromirror array as the pattern matrix of single pixel detection in the past, adopt time domain impulse modulation signal as the measurement module matrix of compression sampling.

Optical signal generator in the embodiment of the present invention can be any LASER Light Source directly or indirectly sending pulse signal, that is, include the LASER Light Source that pulse exports, such as: short optical pulse source, ultrashort light pulse source; And the LASER Light Source that the continuous wave that can modulate exports, such as: noncoherent broadband light source.Ultrashort light pulse source can adopt active mode laser instrument or laser with active-passive lock mould to realize; Noncoherent broadband light source can adopt multiple-wavelength laser, multi-wavelength laser array, and wide range noise light source etc. realizes.The effect of light source be to provide a spectrum be used for irradiating want the target scene of imaging, the information of target scene is mapped to spectrally by effects such as reflection, scattering, absorptions.

Embodiment one

According to one embodiment of present invention, Active Imaging process is as described below.

Fig. 1 a and Fig. 1 b is the imaging system Organization Chart of embodiment 1, participates in Fig. 1, and first, the pulsed optical signals that paired pulses optical signal generating apparatus produces carries out spectral modulation, makes light signal raise the calculation matrix sequence being shaped with compression sampling in time domain.

In embodiments of the present invention, adopt pulse optical signal generating device as the light source of imaging system, different pulse signal generators produces the light signal with different spectrum width B.Pulse optical signal generating device 101 in working order under, produce pulsed optical signals, this pulsed optical signals can be expressed as f (ω) at frequency domain, and wherein, ω is the angular frequency of light.The pulsed optical signals f (ω) exported by pulse optical signal generating device 101, first through first Dispersive Devices 102, makes the frequency spectrum of light signal f (ω) launch in time domain, and the dispersion values of this first Dispersive Devices 102 is D1.Then, the pulsed optical signals f (ω) after being launched by frequency spectrum is input in the first optical spectral modulator 103 and carries out spectral modulation, is modulated at light signal spectrally to make the pulse-modulated signal as calculation matrix.Alternatively, calculation matrix, by any waveform generator or the pattern generator generation that produce pulse, has illustrated situation about being produced by the first pattern generator 104 in Fig. 1.First, the first pattern generator 104 produces pseudo-random code pulse signal p (t) according to the imaging resolution of the final image expected, wherein, t is the time.This pseudo-random code pulse signal is equivalent to the measured value in the calculation matrix of compression sampling, convert different pseudo-random code sequences, multiple different measured value can be obtained, the resolution of the image expected is higher, namely the pixel number of image is more, just needs to produce more different pseudo-random code sequences and takes multiple measurements.Such as, if the pixel number of image is N, then need each pseudo-random code produced to have N number of chip, measure for M time, generally, M is less than N, and alternatively, M is the 20%-40% of N.M measurement will produce the capable pseudo-random code sequence of M, thus form the calculation matrix Φ of a M × N in modulated process, namely

In this calculation matrix Φ, every a line is exactly a pseudo-random code, represents and carries out one-shot measurement to image, carries out M time altogether and measures, and measure for this M time and be used for follow-up recovery one sub-picture (two field picture), like this, a frame imaging uses a calculation matrix.Alternatively, when needs carry out dynamic video typing to target scene, different calculation matrix can be converted and carry out repeatedly fast imaging, with formative dynamics video data.

In embodiments of the present invention, pseudo-random code pulse signal p (t) has low duty ratio, dutycycle is Δ t/T, wherein Δ t is pulse width, T is the pulse repetition time, the spectrum width B of light signal that the ratio of Δ t and T is produced by the pulse optical signal generating device 101 and dispersion values D1 of the first Dispersive Devices 102 determines, low duty ratio ensure that light pulse signal is after the first Dispersive Devices 102, and the light pulse signal of broadening does not occur overlapping.

Use pseudo-random code pulse signal p (t) to drive the first optical spectral modulator 103, modulation formula is as follows:

$s\left(t\right)=p\left(t\right)\×F^{-1}[f\left(\mathrm{\ω}\right)\×\exp \left(\frac{j{\mathrm{\β}}_2{\mathrm{\ω}}^2}{2}\right)]$

Wherein s (t) is through the signal after modulation, and p (t) is pseudo-random code sequence, F ^-1[] represents inverse Fourier transform, and f (ω) represents pulsed optical signals, and j is imaginary unit, and ω is the angular frequency of pulsed optical signals, β ₂the dispersion parameters of the first Dispersive Devices 102, β ₂with the relation of dispersion values D1 be:

${\mathrm{\β}}_2=-\frac{{\mathrm{\λ}}^2}{2\mathrm{\πc}}D1$

Wherein λ is the centre wavelength of pulsed optical signals f (ω) pulse, and c is the light velocity.

After having modulated, the pulsed optical signals after modulation is input to photoimaging equipment.

Pulsed optical signals is after pseudo-random code p (t) modulation, the pulsed optical signals f (ω) being equivalent to paired pulses optical signal generating apparatus 101 output is provided with the calculation matrix of a M × N in time domain, light signal s (t) after the first optical spectral modulator 103 is modulated is input in photoimaging systems 105 and carries out imaging, photoimaging systems generally comprises scattered grating 1051 and lens 1052, alternatively, polarization adjuster 1053 etc. can also be comprised, wherein, scattered grating 1051 is for carrying out scattering to the frequency spectrum of light pulse, polarization adjuster 1053 carries out polarization adjustment for the pulse interval distribution of paired pulses light signal s (t), lens 1052 are for beams converge.Scattered grating 1051 can also change other periodically light scatterings into; Lens can be microcobjectives, focusing objective len; Polarization adjusting device can be half-wave plate, quarter-wave plate etc.

In imaging process, first, pulsed optical signals s (t) after modulating is allowed to enter scattered grating 1051, optical signal spectrum is spatially scattered, and then focus on through lens 1052, the light signal appeared from lens forms in lens focus the hot spot that has size, this spot size and the parameters such as lens 1052 size, focal length, aperture and relevant with the parameter such as groove number and size of scattered grating 1051.Needing the hot spot of different size or varying strength, can regulate by regulating the parameter of lens and scattered grating.If need the pulsed optical signals after to modulation to carry out polarization adjustment, pulsed optical signals s (t) so after modulation first through polarization adjusting device 1053, then can enter scattered grating 1051, finally enters in the middle of lens 1052.

Use the target illuminated scene exported from photoimaging equipment.

Like this, the pulsed optical signals after imaging device, defines a hot spot at lens 1052 focus place, by the near focal point needing the target scene S of imaging to be placed on the lens 1052 of imaging system, the light of hot spot is irradiated in target scene.Generally, target scene can be placed on focal length of lens focus place, and the size of target scene is less than or equal to spot size.Target scene can be plane scene, also can be 3 D stereo scene.

The reflected light of optical acquisition device to target scene is used to gather.

Optical acquisition device 106 can adopt the second lens 1061 to realize, and as required, the parameters of the second lens 1061 can be identical with the first lens 1052, also can be different.As shown in Figure 1, second lens 1061 are placed on a fixed position, in this position, second lens 1061 are the focal length of the second lens 1061 to the distance length of target scene, the effect that reflected light can be made to converge like this is best, and the information major part of target scene can reflex on the second lens 1061.Pulsed optical signals d (t) collected contains information and the target scene k (ω of pulsed optical signals s (t) _s) information, namely

d(t)＝s(t)×k(ω _s)

Wherein ω _sit is the spatial frequency of target scene.

After collecting reflected light, Image Reconstruction is carried out to reflected light d (t) collected.

After collecting reflected light, Image Reconstruction can be carried out by the target scene of Image Reconstruction device 108 pairs of imagings.Light signal d (t) collected from the second lens 1061, first through the second Dispersive Devices 107, makes the pulsed optical signals collected compress in time domain, thus its time domain width is narrowed.The dispersion values of this second Dispersive Devices 107 is that D2, D2 are contrary with the dispersion values D1 symbol of the first Dispersive Devices 102, i.e. D2=-D1.Because the processing procedure of light signal on above-mentioned device is physical treatment course, do not relate to complicated digital computation, therefore, greatly accelerate the speed of imaging.

Then, utilize a photoelectric commutator 1081 to receive the light pulse signal after compression, converting optical signals is become electric signal.Alternatively, photoelectric commutator 1081 can the total power of received pulse light signal, also can receive only the peak power of light pulse signal.This photoelectric commutator 1081 can use the devices such as photodetector, photodiode, photomultiplier to realize.Wherein, the bandwidth of photodetector is more than or equal to 1/T, and wherein, T is the cycle of light pulse.

Electric signal after conversion is admitted in the digital processing unit 1082 of rear end, and utilize the pseudo-random code p (t) that pattern generator 103 above produces, be reconstructed the image of imaging, reconstructed image can utilize display 1083 to show.Signal after overcompression is as follows:

Wherein Y is the electric signal matrix be admitted in digital processing system, and Φ is calculation matrix, and the pseudo-random sequence that what wherein every a line represented is in one-shot measurement, total M is capable, i.e. M measurement, and the image information of X for recovering, N is the pixel number of image.

The object of restructing algorithm is exactly in the middle of measured value Y, recovers original image X according to calculation matrix Φ.Restructing algorithm is specific as follows.

Input: original signal X ∈ R ⁿ, degree of rarefication is K; (each symbol will with corresponding above on)

Observing matrix Φ ∈ R ^m*N

Observation vector Y ∈ R ^m, R is rational real number collection.

Export: reconstruction signal

1, each parameter of initialization: reconstruction signal residual error r ₀=Y,

Indexed set ∧ ₀=Φ, coupling matrix D ₀=Φ, iterations t=1;

2, index λ is found _t, make it meet

3, indexed set, coupling matrix: ∧ is upgraded _t=∧ _t-1∪ { λ _t, D _t=Dt-1,

4, residual error is upgraded: $r_t=r_{t-1}-{\mathrm{\Φ}}_{{\mathrm{\λ}}_t}{\mathrm{\Φ}}_{{\mathrm{\λ}}_t}^{+}{r}_{t-1};$ Here, for pseudo inverse matrix: ${\mathrm{\Φ}}_{{\mathrm{\λ}}_t}^{+}={\left({\mathrm{\Φ}}_{{\mathrm{\λ}}_t}^T{\mathrm{\Φ}}_{{\mathrm{\λ}}_t}\right)}^{-1}{\mathrm{\Φ}}_{{\mathrm{\λ}}_t}^T;$

5, nonzero element corresponding in X is solved:

6, iterations adds 1, inspection iteration stopping condition.If t≤k, then return step 2; Otherwise perform step 7;

7, reconstruction signal is exported: by at the signal that correspondence position produces the signal that will reconstruct exactly.

Or, algorithm below also can be adopted to carry out Image Reconstruction.

Input: original signal X ∈ R ⁿ, degree of rarefication is K;

Observing matrix Φ ∈ R ^m*N

Observation vector Y ∈ R ^m,

Export: reconstruction signal

1, each parameter of initialization: reconstruction signal residual error r ₀=Y, indexed set ∧ ₀=Φ, iterations t=1;

2, index λ is found _t, make it meet

3, indexed set: ∧ is upgraded _t=∧ _t-1∪ { λ _t;

4, signal indexed set screening: ${\mathrm{\Λ}}_t=\arg \underset{K}{\max }\left(\right|{\mathrm{\Φ}}_{{\mathrm{\Λ}}_t}^{+}y\left|\right);$

5, residual error is upgraded: $r_t=y-{\mathrm{\Φ}}_{{\mathrm{\Λ}}_t}\left({\mathrm{\Φ}}_{{\mathrm{\Λ}}_t}^{+}y\right);$ Here, for pseudo inverse matrix: ${\mathrm{\Φ}}_{{\mathrm{\λ}}_t}^{+}={\left({\mathrm{\Φ}}_{{\mathrm{\λ}}_t}^T{\mathrm{\Φ}}_{{\mathrm{\λ}}_t}\right)}^{-1}{\mathrm{\Φ}}_{{\mathrm{\λ}}_t}^T;$

6, iteration stopping condition is checked: judge whether to meet ‖ r _t‖ ₂>=‖ r _t-1‖ ₂if meet, then stop iteration, calculate if do not meet, then t=t+1, returns step 2.

7, reconstruction signal is exported: by at the signal that correspondence position produces the signal that will reconstruct exactly.

To sum up, the Active Imaging method based on compression sampling of the embodiment of the present invention, light signal time domain superposes random signal, high speed optoelectronic modulator is utilized to apply time domain measurement at a high speed, and utilize Dispersive Devices to carry out area of light squeeze operation, whole processing procedure make use of photoelectric effect or physical influence, does not need mechanical adjust structure, avoid the physical constructions such as the digital micromirror array in the middle of traditional single pixel imaging system, substantially increase image taking speed.The frame per second of the single pixel imaging utilizing digital micromirror array to realize is at below 100Hz, and the frame per second of the single pixel imaging utilizing this technology to realize is at more than 100kHz, and image taking speed is than fast 1000 times of the compression sampling imaging technique based on digital micromirror array.

Embodiment two

According to still another embodiment of the invention, the Active Imaging process based on compression sampling is as follows.

Fig. 2 a and Fig. 2 b is the imaging system Organization Chart of embodiment two, see Fig. 2, first, pulsed optical signals is input to photoimaging equipment and carries out imaging processing;

In embodiments of the present invention, adopt pulse optical signal generating device as the light source of imaging system, different pulse signal generators produces the light signal of different spectrum width B.Pulse optical signal generating device 201 in working order under, produce pulsed optical signals, this pulsed optical signals can be expressed as f (ω) at frequency domain, and wherein, ω is the angular frequency of light.Pulsed optical signals f (ω) is input in photoimaging systems 205 and carries out imaging, photoimaging systems generally comprises scattered grating 2051 and lens 2052, alternatively, polarization adjuster 2053 etc. can also be comprised, wherein, scattered grating 2051 is for carrying out scattering to the frequency spectrum of light pulse, and polarization adjuster 2053 carries out polarization adjustment for the pulse interval distribution of paired pulses light signal f (ω), and lens 2052 are for beams converge.Scattered grating 2051 can also change other periodically light scatterings into; Lens can be microcobjectives, focusing objective len; Polarization adjusting device can be half-wave plate, quarter-wave plate etc.

In imaging process, first, pulsed optical signals f (ω) is allowed to enter scattered grating 2051, optical signal spectrum is spatially scattered, and then focus on through the first lens 2052, the light signal appeared from the first lens forms in lens focus the hot spot that has size, this spot size and the parameters such as the first lens 2052 size, focal length, aperture and relevant with the parameter such as groove number and size of scattered grating 2051.Need the hot spot of different size or varying strength, can be regulated by the parameter of adjustment first lens and scattered grating.If also need paired pulses light signal to carry out polarization adjustment, so then pulsed optical signals f (ω) first through polarization adjusting device 2053, can enter scattered grating 2051, finally enters in the middle of the first lens 2052.

Use the target illuminated scene exported from photoimaging equipment;

Through the pulsed optical signals of imaging system, define a hot spot at lens 2052 focus place, by the near focal point needing the target scene S of imaging to be placed on the lens 2052 of imaging system, the light of hot spot is irradiated on target scene S.Generally, target scene can be placed on focal length of lens focus place, and the size of target scene is less than or equal to spot size.Target scene can be plane scene, also can be 3 D stereo scene.

Optical acquisition device is used to gather the reflected light of target scene reflectivity;

Optical acquisition device 206 can adopt the second lens 2061 to realize, and as required, the parameter of the second lens 2061 is identical with the first lens 2052, also can be different.As shown in the figure, lens 2061 are placed on a fixed position, in this position, the second lens 2061 are the focal length of the second lens 2061 to the distance length of target scene, the effect that reflected light can be made to converge like this is best, and the information major part of target scene can reflex on the second lens 2061.Pulsed optical signals d (t) collected contains information and the target scene k (ω of pulsed optical signals f (ω) _s) information, namely

d(t)＝F ^-1[f(ω)×k(ω _s)]

Wherein t is the time parameter of the pulsed optical signals collected, ω _sit is the spatial frequency of target scene.

Described reflected light signal is carried out spectral modulation.

By pulsed optical signals d (t) that collects first through first Dispersive Devices 202, the frequency spectrum of light signal d (t) is launched in time domain, and the dispersion values of this first Dispersive Devices 202 is D1.Then, pulsed optical signals d (t) after being launched by frequency spectrum is input in the first optical spectral modulator 203 and carries out spectral modulation, is modulated at light signal d (t) spectrally to make the pulse-modulated signal as calculation matrix.Alternatively, calculation matrix, by any waveform generator or the pattern generator generation that can produce pulse, there is shown situation about being produced by pattern generator 204.First, pattern generator 204 produces pseudo-random code pulse signal p (t) according to the imaging resolution of the final image expected, wherein, t is the time.This pseudo-random code pulse signal is equivalent to the measured value in the calculation matrix of compression sampling, convert different pseudo-random code sequences, multiple different measured value can be obtained, the resolution of the image expected is higher, namely the pixel number of image is more, just needs to produce more different pseudo-random code sequences and takes multiple measurements.Such as, if the vegetarian refreshments number of image is N, then need each pseudo-random code produced to have N number of chip, measure for M time, generally, M is less than N, and alternatively, M is the 20%-40% of N.M measurement will produce the capable pseudo-random code sequence of M, thus form the calculation matrix Φ of a M × N in modulated process, namely

In this calculation matrix Φ, every a line is exactly a pseudo-random code, represents and carries out one-shot measurement to image, carries out M time altogether and measures, and measure for this M time and be used for follow-up recovery one sub-picture (two field picture), like this, a frame imaging uses a calculation matrix.Alternatively, when needs carry out dynamic video typing to target scene, different calculation matrix can be converted and carry out repeatedly fast imaging, with formative dynamics video data.

In embodiments of the present invention, pseudo-random code pulse signal p (t) has low duty ratio, dutycycle is Δ t/T, wherein Δ t is pulse width, T is the pulse repetition time, the spectrum width B of light signal that the ratio of Δ t and T is produced by the pulse optical signal generating device 201 and dispersion values D1 of the first Dispersive Devices 202 determines, low duty ratio ensure that light pulse signal is after the first Dispersive Devices 202, and the light pulse signal of broadening does not occur overlapping.

Use pseudo-random code pulse signal p (t) to drive the first optical spectral modulator 203, modulation formula is as follows:

$s\left(t\right)=p\left(t\right)\×F^{-1}\left\{F\right[d\left(t\right)]\×\exp \left(\frac{j{\mathrm{\β}}_2{\mathrm{\ω}}^2}{2}\right)\}$

Wherein s (t) is through the signal after modulation, and d (t) is the pulsed optical signals collected, and p (t) is pseudo-random code sequence, F ^-1[] represents inverse Fourier transform, and j is imaginary unit, and ω is the angular frequency of pulsed optical signals, β ₂the dispersion parameters of the first Dispersive Devices 202, β ₂with the relation of dispersion values D1 be:

${\mathrm{\β}}_2=-\frac{{\mathrm{\λ}}^2}{2\mathrm{\πc}}D1$

Wherein λ is the centre wavelength of pulsed optical signals, and c is the light velocity.

Image Reconstruction is carried out to the light signal after modulation.

Light signal after modulation can carry out the reconstruct of image by Image Reconstruction device 208.Pulsed optical signals d (t), after pseudo-random code p (t) modulation, is equivalent to the calculation matrix that paired pulses light signal d (t) is provided with a M × N in time domain.Afterwards, pulsed optical signals s (t) after modulation, first through the second dispersive medium 207, makes it to compress in time domain, thus its time domain width is narrowed.The dispersion values of this second Dispersive Devices 207 is that D2, D2 are contrary with the dispersion values D1 symbol of the first Dispersive Devices 202, i.e. D2=-D1.Because the processing procedure of light signal on above-mentioned device is physical treatment course, do not relate to complicated digital computation, therefore, greatly accelerate the speed of imaging.

Then, utilize a photoelectric commutator 2081 to receive the light pulse signal after compression, converting optical signals is become electric signal.Alternatively, photoelectric commutator 2081 can the total power of received pulse light signal, also can receive only the peak power of light pulse signal.This photoelectric commutator 2081 can use the devices such as photodetector, photodiode, photomultiplier to realize.Wherein, the bandwidth of photodetector is more than or equal to 1/T, and wherein, T is the cycle of light pulse.

Electric signal after conversion is admitted in the digital processing unit 2082 of rear end, and utilize the pseudo-random code p (t) that pattern generator 203 above produces, be reconstructed the image of imaging, the image obtained after reconstruct can be shown by display 2083.Signal after overcompression is as follows:

Wherein Y is the electric signal matrix be admitted in digital processing system, and Φ is calculation matrix, and the pseudo-random sequence that what wherein every a line represented is in one-shot measurement, total M is capable, i.e. M measurement, and the image information of X for recovering, N is the pixel number of image.

The object of restructing algorithm is exactly in the middle of measured value Y, recovers original image X according to calculation matrix Φ.Concrete restructing algorithm is identical with kind of the algorithm of two in embodiment one, does not repeat them here.

To sum up, the Active Imaging method based on compression sampling of the embodiment of the present invention, light signal time domain superposes random signal, high speed optoelectronic modulator is utilized to apply time domain measurement at a high speed, and utilize Dispersive Devices to carry out area of light squeeze operation, whole processing procedure make use of photoelectric effect or physical influence, does not need mechanical adjust structure, avoid the physical constructions such as the digital micromirror array in the middle of traditional single pixel imaging system, substantially increase image taking speed.The frame per second of the single pixel imaging utilizing digital micromirror array to realize is at below 100Hz, and the frame per second of the single pixel imaging utilizing this technology to realize is at more than 100kHz, and image taking speed is than fast 1000 times of the compression sampling imaging technique based on digital micromirror array.

Embodiment three

According to still another embodiment of the invention, the Active Imaging process based on compression sampling is as follows.

Fig. 3 a and Fig. 3 b is the imaging system Organization Chart of embodiment three, and see Fig. 3, the optical signal generator in the present embodiment adopts the light source of no pulse, such as, incoherent light source, the phase place between each bar spectrum line of incoherent light source has nothing to do, therefore can the amplitude of modulated light signal on this light source effectively.Alternatively, can adopt noncoherent broadband light source, noncoherent broadband light source comprises multiple-wavelength laser, multi-wavelength laser array, broadband noise light source etc.

First time spectral modulation is carried out to the light signal that optical signal generator 301 produces;

First, optical signal generator 301 in working order under, produce light signal, this light signal can be expressed as g (ω) at frequency domain, and wherein, ω is the angular frequency of light.The light signal g (ω) exported by optical signal generator 301 is input in the second optical spectral modulator 310 and carries out spectral modulation, to make pulse signal a (t) be modulated on light signal g (ω), make this light signal in time domain, produce a pulse.Alternatively, pulse signal a (t) of modulation is by any pattern generator or the waveform generator generation that produce pulse, and shown in Figure 3 is produced by the second pattern generator 304.First, the second pattern generator 304 produces sequences of pulsed signals according to the final image taking speed v expected wherein, b () represents the shape of individual pulse, and t is the time, and M is pendulous frequency, i.e. the line number of calculation matrix.T is the cycle of pulse, image taking speed v=1/ (M × T).

Modulated pulse signal a (t) using the second pattern generator 309 to produce drives the second optical spectral modulator 310, and modulation formula is as follows:

c(t)＝a(t)×F ^-1[g(ω)]

Wherein c (t) is through the signal after modulation, F ^-1[] represents inverse Fourier transform, and g (ω) represents the spectrum of light signal, and ω is light signal angular frequency.

In embodiments of the present invention, pulse signal a (t) has low duty ratio, dutycycle is Δ t/T, wherein Δ t is pulse width, T is the pulse repetition time, the spectrum width B of the light signal that the ratio of Δ t and T is produced by the optical signal generator 301 and dispersion values D1 realizing the first Dispersive Devices 302 that optical signal spectrum launches used below determines, low duty ratio ensure that light pulse signal is after the first Dispersive Devices 302, and the light pulse signal of broadening does not occur overlapping.

Alternatively, the second pattern generator 309 can be driven by a clock source 308, and clock source 308 sends cycle clock signal, the cycle T of this clock source 308, as the reference clock of the second pattern generator 309.

Light signal after modulation is input to photoimaging equipment;

After light signal pulsed signal a (t) modulation, the light signal g (ω) be equivalent to optical signal generator 301 exports creates a pulse in time domain, becomes pulsed optical signals c (t).Light signal c (t) after this modulation is input in photoimaging equipment 305 and carries out imaging, photoimaging equipment 305 generally comprises scattered grating 3051 and the first lens 3052, alternatively, polarization adjuster 3053 etc. can also be comprised, wherein, scattered grating 3051 is for carrying out scattering to the frequency spectrum of light pulse, and polarization adjuster 3053 carries out polarization adjustment for the pulse interval distribution of paired pulses light signal c (t), and the first lens 3052 are for beams converge.Scattered grating 3051 can also change other periodically light scatterings into; Lens can be microcobjectives, focusing objective len; Polarization adjusting device 3053 can be half-wave plate, quarter-wave plate etc.

In imaging process, first, pulsed optical signals c (t) obtained after modulating is allowed to enter scattered grating 3051, optical signal spectrum is spatially scattered, and then focus on through the first lens 3052, the light signal appeared from lens forms in lens focus the hot spot that has size, this spot size and the parameters such as the first lens 3052 size, focal length, aperture and relevant with the parameter such as groove number and size of scattered grating 3051.Needing the hot spot of different size or varying strength, can regulate by regulating the parameter of lens and scattered grating.If also need paired pulses light signal to carry out polarization adjustment, then pulsed optical signals c (t) so obtained after modulation first through polarization adjusting device 3053, can enter scattered grating 3051, finally enters in the middle of the first lens 3052.

Use the target illuminated scene exported from described photoimaging equipment;

Pulsed optical signals c (t) after imaging device process, a hot spot is defined at the first lens 3052 focus place, by the near focal point needing the target scene S of imaging to be placed on the first lens 3052 of imaging system, the light of hot spot is irradiated in target scene completely.Generally, target scene can be placed on focal length of lens focus place, and the size of target scene is less than or equal to spot size.Target scene can be plane scene, also can be 3 D stereo scene.

Optical acquisition device is used to gather the reflected light of target scene reflectivity;

Optical acquisition device 306 can adopt the second lens 3061 to realize, and as required, the parameter of the second lens 3061 can be identical with the first lens 3052, also can be different.As shown in Figure 3, lens 3061 are placed on a fixed position, in this position, second lens 3061 are the focal length of the second lens 3061 to the distance length of target scene, the effect that reflected light can be made to converge like this is best, and the information major part of target scene can reflex on the second lens 3061.Pulsed optical signals d (t) collected contains information and the target scene k (ω of pulsed optical signals c (t) _s) information, namely

d(t)＝c(t)×k(ω _s)

Wherein ω _sit is the spatial frequency of target scene.

The reflected light signal collected is carried out second time spectral modulation.

First, the spectrum of light signal d (t) collected is launched in time domain, Dispersive Devices can be utilized to realize.Be input to by light signal d (t) collected in the middle of the first Dispersive Devices 302, the dispersion values of this Dispersive Devices 302 is D1, the moment that different frequecny captures is different.

Then, light signal d (t) after time domain is launched is carried out second time spectral modulation, be modulated at light signal d (t) spectrally to make the pulse-modulated signal as calculation matrix.Alternatively, calculation matrix is produced by the first pattern generator 304.The reference clock of the first pattern generator 304 and the second pattern generator 309 is synchronous, alternatively, can be made the clock synchronous of the first pattern generator 304 and the second pattern generator 309 by a synchronizing signal; Also the first pattern generator 304 and the second pattern generator 309 can be triggered, to ensure the synchronous of two modulated processs by same clock source.

In modulated process, first, pulsed optical signals d (t) after time domain being launched inputs the first optical spectral modulator 303.This modulator is driven by the first pattern generator 304, and drive singal is pseudo-random code (PRBS), and the pulse signal cycle of pseudo-random code is T.First pattern generator 304 produces pseudo-random code pulse signal p (t) according to the imaging resolution of the final image expected, wherein, t is the time.This pseudo-random code pulse signal is equivalent to the measured value in the calculation matrix of compression sampling, convert different pseudo-random code sequences, multiple different measured value can be obtained, the resolution of the image expected is higher, namely the pixel number of image is more, just needs to produce more different pseudo-random code sequences and takes multiple measurements.Such as, if the vegetarian refreshments number of image is N, then need each pseudo-random code produced to have N number of chip, measure for M time, generally, M is less than N, and alternatively, M is the 20%-40% of N.M measurement will produce the capable pseudo-random code sequence of M, thus form the calculation matrix Φ of a M × N in modulated process, namely

In this calculation matrix Φ, every a line is exactly a pseudo-random code, represents and carries out one-shot measurement to image, carries out M time altogether and measures, and measures for this M time and is used for follow-up recovery one sub-picture, has used a calculation matrix to carry out so Polaroid.Alternatively, when needs carry out dynamic video typing to target scene, different calculation matrix can be converted and carry out repeatedly fast imaging.

In embodiments of the present invention, pseudo-random code pulse signal p (t) has low duty ratio, dutycycle is Δ t/T, wherein Δ t is pulse width, T is the pulse repetition time, the spectrum width B of light signal that the ratio of Δ t and T is produced by the optical signal generator 301 and dispersion values D1 of the first Dispersive Devices 302 determines, low duty ratio ensure that light pulse signal is after the first Dispersive Devices 302, and the light pulse signal of broadening does not occur overlapping.

Use pseudo-random code pulse signal p (t) to drive the first optical spectral modulator 303, modulation formula is as follows:

$s\left(t\right)=p\left(t\right)\×F^{-1}[F\left(d\left(t\right)\right)\×\exp \left(\frac{j{\mathrm{\β}}_2{\mathrm{\ω}}^2}{2}\right)]$

Wherein s (t) is through the signal after modulation, and p (t) is pseudo-random code sequence, F ^-1[] represents inverse Fourier transform, and F represents Fourier transform, and d (t) represents the pulsed optical signals collected, and j is imaginary unit, and ω is the angular frequency of pulsed optical signals d (t), β ₂the dispersion parameters of the first Dispersive Devices 302, β ₂with the relation of dispersion values D1 be:

${\mathrm{\β}}_2=-\frac{{\mathrm{\λ}}^2}{2\mathrm{\πc}}C1$

Wherein λ is the centre wavelength of pulsed optical signals, and c is the light velocity.

Image Reconstruction is carried out to the light signal after second time spectral modulation.

Light signal after modulation can carry out the reconstruct of image by Image Reconstruction device 311.Light signal s (t) obtained after twice modulation, first through the second dispersive medium 307, makes this pulsed optical signals s (t) compress in time domain, thus its time domain width is narrowed.The dispersion values of this second Dispersive Devices 307 is that D2, D2 are contrary with the dispersion values D1 symbol of the first Dispersive Devices 302, i.e. D2=-D1.Because the processing procedure of light signal on above-mentioned device is physical treatment course, do not relate to complicated digital computation, therefore, greatly accelerate the speed of imaging.

Then, utilize a photoelectric commutator 3111 to receive light pulse signal s (t) after compression, converting optical signals is become electric signal.Alternatively, photoelectric commutator 3111 can the total power of received pulse light signal, also can receive only the peak power of light pulse signal.This photoelectric commutator 3111 can use the devices such as photodetector, photodiode, photomultiplier to realize.Wherein, the bandwidth of photodetector is more than or equal to 1/T, and wherein, T is the cycle of light pulse.

Electric signal after conversion is admitted in the digital processing unit 3112 of rear end, and utilize the pseudo-random code p (t) that the first pattern generator 304 above produces, be reconstructed the image of imaging, reconstructed image is shown by display 3113.Signal after overcompression is as follows:

Wherein Y is the electric signal matrix be admitted in digital processing system, and Φ is calculation matrix, and the pseudo-random sequence that what wherein every a line represented is in one-shot measurement, total M is capable, i.e. M measurement, and the image information of X for recovering, N is the pixel number of image.

The object of restructing algorithm is exactly in the middle of measured value Y, recovers original image X according to calculation matrix Φ.Identical with embodiment one of concrete restructing algorithm, does not repeat them here.

To sum up, the Active Imaging method based on compression sampling of the embodiment of the present invention, light signal time domain superposes random signal, high speed optoelectronic modulator is utilized to apply time domain measurement at a high speed, and utilize Dispersive Devices to carry out area of light squeeze operation, whole processing procedure make use of photoelectric effect or physical influence, does not need mechanical adjust structure, avoid the physical constructions such as the digital micromirror array in the middle of traditional single pixel imaging system, substantially increase image taking speed.And light source is the non-coherent broad band light source of external modulation, and structure has universality more.The frame per second of the single pixel imaging utilizing digital micromirror array to realize is at below 100Hz, and the frame per second of the single pixel imaging utilizing this technology to realize is at more than 100kHz, and image taking speed is than fast 1000 times of the compression sampling imaging technique based on digital micromirror array.

Embodiment four

According to still another embodiment of the invention, the Active Imaging process based on compression sampling is as follows.

The light signal produced from optical signal generator is carried out first time spectral modulation.

Fig. 4 a and Fig. 4 b is the imaging system Organization Chart of embodiment 4, see Fig. 4, first, optical signal generator 401 in working order under, produce light signal, this light signal can be expressed as g (ω) at frequency domain, and wherein, ω is the angular frequency of light.The light signal g (ω) exported by optical signal generator 401 is input in the second optical spectral modulator 407 and carries out spectral modulation, to make pulse signal a (t) be modulated on light signal g (ω), make this light signal in time domain, produce a pulse.Alternatively, pulse signal a (t) of modulation is by any pattern generator or the waveform generator generation that can produce pulse, and shown in Figure 4 is produced by the second pattern generator 409.Second pattern generator 409 produces sequences of pulsed signals according to the final image taking speed v expected wherein, b () represents the shape of individual pulse, and t is the time, and M is pendulous frequency, i.e. the line number of calculation matrix.T is the cycle of pulse, image taking speed v=1/ (M × T).

Modulated pulse signal a (t) using the second pattern generator 409 to produce drives the second optical spectral modulator 407, and modulation formula is as follows:

c(t)＝a(t)×F ^-1[g(ω)]

Wherein c (t) is through the signal after modulation, F ^-1[] represents inverse Fourier transform, and g (ω) represents the spectrum of light signal, and ω is light signal angular frequency.

In embodiments of the present invention, pulse signal a (t) has low duty ratio, dutycycle is Δ t/T, wherein Δ t is pulse width, T is the pulse repetition time, the spectrum width B of the light signal that the ratio of Δ t and T is produced by the optical signal generator 401 and dispersion values D1 realizing the first Dispersive Devices 402 that optical signal spectrum launches used below determines, low duty ratio ensure that light pulse signal is after the first Dispersive Devices 402, and the light pulse signal of broadening does not occur overlapping.

Alternatively, the second pattern generator 409 can be driven by a clock source 408, and clock source 408 sends cycle clock signal, the cycle T of this clock source 408, as the reference clock of the second pattern generator 409.

The light signal passing through first time spectral modulation is carried out second time spectral modulation.

After light signal pulsed signal a (t) modulation, the light signal g (ω) be equivalent to optical signal generator 401 exports creates a pulse in time domain, becomes pulsed optical signals c (t).Afterwards, then to it second time modulation is carried out.First, the spectrum of pulsed optical signals c (t) is launched in time domain, Dispersive Devices can be utilized to realize, light signal c (t) is input in the middle of the first Dispersive Devices 402, the dispersion values of this Dispersive Devices 402 is D1, the moment that different frequecny captures is different.

Then, pulsed optical signals c (t) is carried out second time spectral modulation, be modulated at light signal c (t) spectrally to make the pulse-modulated signal as calculation matrix.Alternatively, calculation matrix is produced by the first pattern generator 404.The reference clock of the first pattern generator 404 and the second pattern generator 409 is synchronous, alternatively, the signal of the first pattern generator 404 and the second pattern generator 409 can be made synchronous by a synchronizing signal; Also can trigger the first pattern generator 404 and the second pattern generator 409 by same clock source simultaneously, identical to ensure the reference clock of two generators.

In modulated process, first, pulsed optical signals c (t) after pulsed optical signals time domain being launched inputs the first optical spectral modulator 403.This modulator is driven by the first pattern generator 404, and drive singal is pseudo-random code (PRBS), and the pulse signal cycle of pseudo-random code is T.First pattern generator 404 produces pseudo-random code pulse signal p (t) according to the imaging resolution of the final image expected, wherein, t is the time.This pseudo-random code pulse signal is equivalent to the measured value in the calculation matrix of compression sampling, convert different pseudo-random code sequences, multiple different measured value can be obtained, the resolution of the image expected is higher, namely the pixel number of image is more, just needs to produce more different pseudo-random code sequences and takes multiple measurements.Such as, if the vegetarian refreshments number of image is N, then need each pseudo-random code produced to have N number of chip, measure for M time, generally, M is less than N, and alternatively, M is the 20%-40% of N.M measurement will produce the capable pseudo-random code sequence of M, thus form the calculation matrix Φ of a M × N in modulated process, namely

In this calculation matrix Φ, every a line is exactly a pseudo-random code, represents and carries out one-shot measurement to image, carries out M time altogether and measures, and measures for this M time and is used for follow-up recovery one sub-picture, has used a calculation matrix to carry out so Polaroid.Alternatively, when needs carry out dynamic video typing to target scene, different calculation matrix can be converted and carry out repeatedly fast imaging.

In embodiments of the present invention, pseudo-random code pulse signal p (t) has low duty ratio, dutycycle is Δ t/T, wherein Δ t is pulse width, T is the pulse repetition time, the spectrum width B of light signal that the ratio of Δ t and T is produced by the optical signal generator 401 and dispersion values D1 of the first Dispersive Devices 402 determines, low duty ratio ensure that light pulse signal is after the first Dispersive Devices 402, and the light pulse signal of broadening does not occur overlapping.

Use pseudo-random code pulse signal p (t) to drive the first optical spectral modulator 403, modulation formula is as follows:

$s\left(t\right)=p\left(t\right)\×F^{-1}[F\left(c\left(t\right)\right)\×\exp \left(\frac{j{\mathrm{\β}}_2{\mathrm{\ω}}^2}{2}\right)]$

Wherein s (t) is through the signal after modulation, and p (t) is pseudo-random code sequence, F ^-1[] represents inverse Fourier transform, and F represents Fourier transform, and c (t) represents the pulsed optical signals after primary modulation, and j is imaginary unit, and ω is the angular frequency of pulsed optical signals c (t), β ₂the dispersion parameters of the first Dispersive Devices 402, β ₂with the relation of dispersion values D1 be:

${\mathrm{\β}}_2=-\frac{{\mathrm{\λ}}^2}{2\mathrm{\πc}}D1$

Wherein λ is the centre wavelength of pulsed optical signals, and c is the light velocity.

Light signal after modulation is input to photoimaging equipment;

Pulsed optical signals is after pseudo-random code p (t) modulation, be equivalent to the calculation matrix that paired pulses light signal c (t) is provided with a M × N in time domain, light signal s (t) after the second optical spectral modulator 407 and the first optical spectral modulator 403 are modulated is input in photoimaging systems 405 and carries out imaging, photoimaging systems generally comprises scattered grating 4051 and lens 4052, alternatively, polarization adjuster 4053 etc. can also be comprised, wherein, scattered grating 4051 is for carrying out scattering to the frequency spectrum of light pulse, polarization adjuster 4053 carries out polarization adjustment for the pulse interval distribution of paired pulses light signal s (t), lens 4052 are for beams converge.Scattered grating 4051 can also change other periodically light scatterings into; Lens can be microcobjectives, focusing objective len; Polarization adjusting device 4053 can be half-wave plate, quarter-wave plate etc.

In imaging process, first, pulsed optical signals s (t) after modulating is allowed to enter scattered grating 4051, optical signal spectrum is spatially scattered, and then focus on through lens 4052, the light signal appeared from lens forms in lens focus the hot spot that has size, this spot size and the parameters such as lens 4052 size, focal length, aperture and relevant with the parameter such as groove number and size of scattered grating 4051.Needing the hot spot of different size or varying strength, can regulate by regulating the parameter of lens and scattered grating.If also need the pulsed optical signals after to modulation to carry out polarization adjustment, pulsed optical signals s (t) so after modulation first through polarization adjusting device 4053, then can enter scattered grating 4051, finally enters in the middle of lens 4052.

Use the target illuminated scene exported from described photoimaging equipment;

Pulsed optical signals s (t) after imaging device process, a hot spot is defined at lens 4052 focus place, by the near focal point needing the target scene S of imaging to be placed on the lens 4052 of imaging system, the light of hot spot is irradiated in target scene completely.Generally, target scene can be placed on focal length of lens focus place, and the size of target scene is less than or equal to spot size.Target scene can be plane scene, also can be 3 D stereo scene.

Optical acquisition device is used to gather the reflected light of target scene reflectivity;

Optical acquisition device 406 can adopt the second lens 4061 to realize, and as required, the parameter of the second lens 4061 can be identical with the first lens 4052, also can be different.As shown in the figure, lens 4061 are placed on a fixed position, in this position, the second lens 4061 are the focal length of the second lens 4061 to the distance length of target scene, the effect that reflected light can be made to converge like this is best, and the information major part of target scene can reflex on the second lens 4061.Pulsed optical signals d (t) collected contains information and the target scene k (ω of pulsed optical signals s (t) _s) information, namely

d(t)＝s(t)×k(ω _s)

Wherein ω _sit is the spatial frequency of target scene.

Image Reconstruction is carried out to the reflected light gathered.

The reflected light collected can carry out the reconstruct of image by Image Reconstruction device 410.Pulsed optical signals d (t) collected, first through the second dispersive medium 411, makes this pulsed optical signals d (t) compress in time domain, thus its time domain width is narrowed.The dispersion values of this second Dispersive Devices 411 is that D2, D2 are contrary with the dispersion values D1 symbol of the first Dispersive Devices 402, i.e. D2=-D1.Because the processing procedure of light signal on above-mentioned device is physical treatment course, do not relate to complicated digital computation, therefore, greatly accelerate the speed of imaging.

Then, utilize a photoelectric commutator 4101 to receive light pulse signal d (t) after compression, converting optical signals is become electric signal.Alternatively, photoelectric commutator 4101 can the total power of received pulse light signal, also can receive only the peak power of light pulse signal.This photoelectric commutator 4101 can use the devices such as photodetector, photodiode, photomultiplier to realize.Wherein, the bandwidth of photodetector is more than or equal to 1/T, and wherein, T is the cycle of light pulse.

Electric signal after conversion is admitted in the digital processing unit 4102 of rear end, utilize the pseudo-random code p (t) that the second pattern generator 409 above produces, be reconstructed the image of imaging, reconstructing the image obtained can be shown by display 4103.Signal after overcompression is as follows:

Wherein Y is the electric signal matrix be admitted in digital processing system, and Φ is calculation matrix, and the pseudo-random sequence that what wherein every a line represented is in one-shot measurement, total M is capable, i.e. M measurement, and the image information of X for recovering, N is the pixel number of image.

The object of restructing algorithm is exactly in the middle of measured value Y, recovers original image X according to calculation matrix Φ.Concrete restructing algorithm is identical with embodiment one, does not repeat them here.

To sum up, the Active Imaging method based on compression sampling of the embodiment of the present invention, light signal time domain superposes random signal, high speed optoelectronic modulator is utilized to apply time domain measurement at a high speed, and utilize Dispersive Devices to carry out area of light squeeze operation, whole processing procedure make use of photoelectric effect or physical influence, does not need mechanical adjust structure, avoid the physical constructions such as the digital micromirror array in the middle of traditional single pixel imaging system, substantially increase image taking speed.And light source is the non-coherent broad band light source of external modulation, and structure has universality more.The frame per second of the single pixel imaging utilizing digital micromirror array to realize is at below 100Hz, and the frame per second of the single pixel imaging utilizing this technology to realize is at more than 100kHz, and image taking speed is than fast 1000 times of the compression sampling imaging technique based on digital micromirror array.

Claims (20)

1. based on an active imaging system for compression sampling,

It is characterized in that,

Comprise:

Pulse optical signal generating device, for generation of pulsed optical signals;

Photoimaging equipment, carries out imaging for the pulsed optical signals produced described pulse optical signal generating device;

Optical acquisition device, the reflected light formed for irradiating target scene to the pulsed optical signals after photoimaging equipment process gathers;

First photomodulator, carries out the first spectral modulation for the reflected light collected described optical acquisition device;

Image Reconstruction device, for carrying out Image Reconstruction to the pulsed optical signals after the first light modulator modulates.

2. system according to claim 1,

It is characterized in that,

Described imaging system also comprises:

First pattern generator, produces pseudo-random code for the resolution according to the image expected, and is input in described first photomodulator by the described pseudo-random code produced;

On the pulsed optical signals of the reflected light that described pscudo-random codc modulation gathers to described optical acquisition device by described first photomodulator.

3. according to the arbitrary described system of claim 1-2,

It is characterized in that,

Described imaging system also comprises: the first Dispersive Devices;

Described first Dispersive Devices launches in time domain for the frequency spectrum of the pulsed optical signals by described reflected light;

Described first photomodulator by described pscudo-random codc modulation on the pulsed optical signals after the first Dispersive Devices process.

4. system according to claim 1,

It is characterized in that,

Described pulse optical signal generating device comprises: have the light source that pulse exports.

5. system according to claim 1,

It is characterized in that,

Described photoimaging equipment comprises: scattered grating and the first lens;

The spectrum that described scattered grating is used for the pulsed optical signals produced by described pulse optical signal generating device carries out scattering;

Described first lens are used for the spectrum after scattering to focus on.

6. system according to claim 1,

It is characterized in that,

Described optical acquisition device comprises: the second lens;

Described second lens are positioned at a fixed position, and in this fixed position, described target scene is the focal length of described second lens to the distance of described second lens.

7. system according to claim 1,

It is characterized in that,

Described Image Reconstruction device comprises:

Photoelectric commutator, for converting the pulsed optical signals through the first optical spectral modulator modulation to electric signal;

Processor, for carrying out computing to electric signal;

Display, for showing the image after reconstruct.

8. system according to claim 7,

It is characterized in that,

Described Image Reconstruction device also comprises:

Second Dispersive Devices;

Described second Dispersive Devices is for compressing in time domain the described pulsed optical signals through the first optical spectral modulator modulation.

9. system according to claim 8,

It is characterized in that,

Described imaging system also comprises: the first Dispersive Devices;

Described first Dispersive Devices launches in time domain for the frequency spectrum of the pulsed optical signals produced by described pulsed optical signals generator;

Described first photomodulator by described pscudo-random codc modulation on the pulsed optical signals after the first Dispersive Devices process;

The dispersion values of described first Dispersive Devices is D1, and the dispersion values of described second device is D2, D1=-D2.

10. system according to claim 1,

It is characterized in that,

Described imaging system also comprises:

First pattern generator, produces pseudo-random code for the resolution according to the image expected, and is input in described first photomodulator by the described pseudo-random code produced;

Described first photomodulator by described pscudo-random codc modulation on the pulsed optical signals of described reflected light;

The pseudo-random code that described Image Reconstruction device uses the first pattern generator to produce carries out single pixel compression to the electric signal after conversion.

11. systems according to claim 1-10,

It is characterized in that,

Described pulse optical signal generating device comprises:

Optical signal generator, the second pattern generator, the second photomodulator;

The light signal that described optical signal generator exports for generation of no pulse;

Described second pattern generator is for generation of pulse signal;

The light signal that described second photomodulator produces to described optical signal generator for the pulse signal modulation produced by described second pattern generator.

12. methods according to claim 11,

It is characterized in that,

Described optical signal generator comprises: noncoherent broadband light source.

13. systems according to claim 11,

It is characterized in that,

Described imaging system also comprises:

First pattern generator, produces pseudo-random code for the resolution according to the image expected, and is input in described first photomodulator by the described pseudo-random code produced;

Described first photomodulator by described pscudo-random codc modulation on the pulsed optical signals of described reflected light;

The reference clock synchronization of described first pattern generator and described second pattern generator.

14. systems according to claim 13,

It is characterized in that,

Described system also comprises: clock source;

Described clock source produces synchronizing clock signals, is input in the first pattern generator and the second pattern generator.

15. 1 kinds of active imaging systems based on compression sampling,

It is characterized in that,

Comprise:

Pulse optical signal generating device, for generation of pulsed optical signals;

First photomodulator, carries out the first spectral modulation for the pulsed optical signals produced described pulse optical signal generating device;

Photoimaging equipment, for carrying out imaging to the pulsed optical signals after the first light modulator modulates;

Optical acquisition device, the reflected light formed for irradiating target scene to the pulsed optical signals after photoimaging equipment process gathers;

Image Reconstruction device, carries out Image Reconstruction for the reflected light collected described optical acquisition device.

16. systems according to claim 15,

It is characterized in that,

Described imaging system also comprises:

First pattern generator, produces pseudo-random code for the resolution according to the image expected, and is input in described first photomodulator by the described pseudo-random code produced;

Described first photomodulator by described pscudo-random codc modulation on described pulsed optical signals.

17. systems according to claim 16,

It is characterized in that,

Described imaging system also comprises:

First pattern generator, produces pseudo-random code for the resolution according to the image expected, and is input in described first photomodulator by the described pseudo-random code produced;

Described first photomodulator by described pscudo-random codc modulation on described pulsed optical signals;

The pseudo-random code that described Image Reconstruction device uses the first pattern generator to produce carries out single pixel compression to the electric signal after conversion.

18. systems according to claim 15-17,

It is characterized in that,

Described pulse optical signal generating device comprises:

Optical signal generator, the second pattern generator, the second photomodulator;

The light signal that described optical signal generator exports for generation of no pulse;

Described second pattern generator is for generation of pulse signal;

The light signal that described second photomodulator produces to described optical signal generator for the pulse signal modulation produced by described second pattern generator.

19. 1 kinds of formation methods based on the active imaging system of compression sampling,

It is characterized in that,

Comprise:

Pulse optical signal generating device is used to produce pulsed optical signals;

The pulsed optical signals produced by described pulse optical signal generating device carries out the first spectral modulation;

Pulsed optical signals after the first spectral modulation is input to photoimaging equipment;

The pulsed optical signals exported from described photoimaging equipment is used to irradiate target scene;

Optical acquisition device is used to gather the reflected light of described target scene;

Image Reconstruction device is used to carry out Image Reconstruction to described reflected light.

20. 1 kinds of formation methods based on the active imaging system of compression sampling,

It is characterized in that,

Comprise:

Pulse optical signal generating device is used to produce pulsed optical signals;

The pulsed optical signals that described pulse optical signal generating device produces is input to photoimaging equipment;

The pulsed optical signals exported from described photoimaging equipment is used to irradiate target scene;

Optical acquisition device is used to gather the reflected light of described target scene;

First spectral modulation is carried out to the reflected light that described optical acquisition device gathers;

Use Image Reconstruction device that the pulsed optical signals after the first spectral modulation is carried out Image Reconstruction.