81 results about "Passive imaging" patented technology

The invention discloses a passive imaging system with a distance measuring function and a distance measuring method of the passive imaging system. The passive imaging system comprises a high-frequency low-energy pulse laser emitting device, a photodiode array detector imaging device, a video amplifying and analog-digital converting device and a digital processing device for digital image processing and timing sequence occurrence. The high-frequency low-energy pulse laser emitting device is used for emitting high-frequency low-energy laser pulses and expanding bundles and shaping to reach a long distance; the photodiode array detector imaging device is used for receiving laser spots and background images reflected by a target and obtaining a distance value by adjusting integral time; the video amplifying and analog-digital converting device is used for converting photogenerated charges of the photodiode array detector imaging device into voltage and digitizing analog images through a analog-digital converter; the digital processing device for digital image processing and timing sequence occurrence is used for preprocessing digital images input by the video amplifying and analog-digital converting device and extracting the target. According to the passive imaging system, high-performance passive imaging and the distance measuring function are combined.

The passive imaging system of the present application includes first and second input polarizers on the light receiving side of a light receiving lens. A first half of the split polarizer performs vertical polarization of incoming light while the second half of the split polarizer performs horizontal polarization of the incoming light. The input polarizing structure provides parallax to accomplish 3D imaging. A third or interleaving polarizer is provided between the lens and an imaging device and is adjacent to and closely spaced from (<10 microns) the image plane of the device. The interleaving polarizer is sectional so that alternating sections, along the direction of parallax created by the input polarizer(s), pass vertically and horizontally polarized light. The resulting image frame formed at the image plane of the imager is similarly sectional so that sections of the image alternate between vertically polarized light and horizontally polarized light, e.g., for example the odd sections of the image are images of vertical polarized light (received from the left side) and even sections of the image are images of horizontally polarized light (received from the right side). Once an image frame has been captured, it is divided into two parallactic image frames, one of vertically polarized light imaged from the left side and one of horizontally polarized light imaged from the right side. The two resulting frames are combined to form a 3D image.

The invention relates to a fast scanning method based on the passive imaging of a single wave beam THz wave. Aiming at the problems of longer scanning time and overhigh system construction cost in an earlier scanning imaging method of the single beam THz wave, a rocker of a crank and rocker mechanism is adopted to drive a line scanning plane mirror to sway horizontally so as to achieve fast transverse scanning motion, and a field scanning plane mirror swaying vertically in a reciprocating way is utilized to realize longitudinal scanning motion, thereby realizing the two-dimensional scanning imaging over object space. On the premise of construction cost reduction, the invention greatly improves the scanning speed per se and simultaneously amplifies the scanning viewing field. In addition, the invention is not only suitable for the passive type THz wave single wave beam scanning imaging, but also suitable for the active type single wave beam scanning imaging of the THz wave.

The invention discloses a license plate recognition system and a license plate recognition method preventing blocking and altering. The method comprises the following steps of: firstly, designing an active and passive imaging system by using the regression reflection property of a license plate to realize highlight displaying of a license plate region in an image and lowlight displaying of a vehicle body, other backgrounds and a blocking and altering material; secondly, designing the license plate recognition method preventing blocking and altering to realize blocking and altering discrimination and character recognition; and finally, improving design of the license plates which have widest application. Compared with the conventional license plate recognition system, the license plate recognition system provided by the invention has a function of preventing blocking and altering and improves the degree of intellectualization of the system; meanwhile, the quality of an acquired license plate image is high, a background noise is low, and the license plate image is insensitive to the change of illumination from the outside, so that a bottleneck effect of the quality of an image source on recognition process is overcome to a large extent.

An underwater imaging system includes an underwater imaging polarimeter that captures images of the water surface. The captured images are indicative of the captured light, and are equivalent to four-component Stokes vector S=(I,Q,U,V) data. Advantageously, the passive imaging technique of the present invention utilizes polarmetric data. In contrast, conventional optical remote sensing techniques rely on light amplitude and frequency to carry information about the scattering surface. The imaging technique of the present invention exploits these properties, as well as the polarization properties of light to sense information about the scattering media. The two-dimensional slope field of surface wave can be recovered from a distance without interfering with the fluid dynamics of the air or water. By employing the physics of light scattering by a specular surface, the geometry of the surface can be found by measuring the polarimetric properties of the reflected and/or refracted light. The derived two-dimensional slope field in then used to remove the image distortion caused by light passing through the wavy surface. The undistorted images have the appearance of images taken through a flat water surface.

The invention discloses an air-based space fragment optical detection and tracking system and method. The system comprises a large-view-field telescope, a small-view-field telescope, a laser range finding machine, and a holder. The method comprises the steps: capturing a rough azimuth angle and a pitch angle of a target through the large-view-field telescope; capturing a precise azimuth angle and a pitch angle of the target through the small-view-field telescope; and measuring the distance with the target through the laser range finding machine. The system employs a passive imaging and laser range finding combination system which consists of the large-view-field telescope, the small-view-field telescope and the laser range finding machine, achieves finding, capturing and tracking of small objects in space through the technology of optical imaging, overcomes the limit that a laser radar is difficult to detect small objects, is low in system power consumption, can quickly and precisely detect the distance and azimuth of the target, and is long in detection distance.

The invention discloses an active-passive imaging system for cat eye target detection. The system comprises a pulse laser, an emission optical system, an optical lens, a CCD detector, a video processing system and a control and delay circuit. The CCD detector conducts image acquisition on a target area through the optical lens, and transmits collected images to the video processing system. When the video processing system detects that transmission of two continuous frames of images is finished, a trigger signal is generated and transmitted to the control and delay circuit, the control and delay circuit immediately generates an electric pulse signal with the effective width equal to the acquisition cycle of the CCD detector after receiving the trigger signal, and then the trigger signal is transmitted to the pulse laser. The pulse laser generates a laser pulse signal according to the electric pulse signal, and emits a laser beam to a target to be detected through the emission optical system. According to the active-passive imaging system for cat eye target detection, generated laser pulses can track the changes of the detector acquisition frame frequency in a self-adaptive mode, so that active imaging quality is improved, and then the passive image matching ratio is improved.

The invention provides a three-dimensional passive imaging method and system for brain focusing ultrasonic cavitation real-time monitoring. On the basis of calibrating cavitation signal distortion due to skull shielding, array elements of a surface array in two directions are subjected to robust Capon beamforming so as to greatly inhibit the interference from other directions and the mutual action between cavitation microbubbles; on the basis of the differences among phases of cavitation signals, a phase correlation coefficient is introduced for correcting a beamforming algorithm, so that the imaging resolution ratio is improved during the imaging artifact inhibition; and finally, a three-dimensional cavitation body is subjected to processing such as data thresholding and smoothening. The method and the system can solve the problems that the detection sensitivity of a conventional magnetic resonance and active ultrasonic imaging monitoring method on the cavitation is insufficient; the real-time monitoring cannot be realized by the active ultrasonic imaging monitoring; and the performance of a conventional passive imaging method is limited, and the like. A real-time monitoring measure for the cavitation effect in the brain focusing ultrasonic treatment process is provided for the clinics, so that the real-time feedback and control of the grain treatment becomes possible.

The invention discloses a virtual time inversion-based sound emission passive imaging method and an apparatus thereof. The method comprises the following steps: receiving n sound emission signals acquired by n piezoelectric patches arranged on a structure to be measured, wherein n is an integer not less than 3; carrying out virtual time reversion treatment on the sound emission signals to obtain reversed signals; extracting the envelope signals of the reversed signals; and imaging according to the envelope signals in order to obtain peak value pixel point positions used as the sound emission source positions of the structure to be measured. The virtual time inversion-based sound emission passive imaging method and the apparatus thereof allow single piezoelectric patch related undetermined absolute wave arrival time in the sound emission signals into a two piezoelectric patches related determined wave arrival time difference through the virtual time reversion treatment, is convenient to realize the highly-precious rapid imaging positioning, does not need the determination of the wave arrival time of the sound emission signals or the calibration of the performances of a piezoelectric transducer, and has low dependence on prior data.

The invention discloses a passive imaging system based on GPS multi-star irradiating and ground single station receiving. In the invention, a plurality of GPS satellites are taken as non-cooperative irradiation sources; a single receiving station fixed on the ground simultaneously receives direct wave signals of the GPS satellites and reflecting wave signals which are reflected by a target and performs a coherent processing to direct waves and reflecting waves; a matching filter method is utilized to invert a target image. The passive imaging system based on the GPS multi-star irradiating and ground single station receiving has the advantages that only a single ground fixing receiving station can finish observation imaging, the cost is low, the complete phase information is maintained during image inversion based on matched filtering, and the terrain deformation information can be extracted through interference processing, so that the passive imaging system based on the GPS multi-star irradiating and ground single station receiving is suitable for being taken as a supplement for SAR and other traditional manners of imaging over the ground and can be widely used for low cost monitoring and predicting in high risk regions, such as landslide body, debris flow, snow slide and the like.

A dual-mode sensor uses the active guidance radiation as a “guide star” to generate a wavefront error estimate for the primary optical element in-situ without interfering with the generation of either the active guidance or passive imaging guidance signals. An array of optical focusing elements performs the normal function of spatially encoding an angle of incidence of the active guidance radiation at an entrance pupil onto an active imaging detector. The array also performs an additional function of spatially encoding wavefront tilt deviations emanating from sub-pupils of an exit pupil onto the active imaging detector. A processor processes the electrical signals from the imaging detector in accordance with the respective spatial encodings to generate an active guidance signal and the wavefront error estimate for the primary optical element.

A system capable of determining wavefront characteristics, such as air induced wavefront aberrations, includes a field programmable gate array (FPGA) device executing a phase diversity algorithm. The FPGA device can be a stand-alone device or comprise multiple FPGAs. The device receives an “in-focus” and an “out-of-focus” image having a known optical difference from that of the “in-focus” image. The device then performs as many phase diversity algorithm iterations as desired to reach an expression for the wavefront aberrations induced on the collected image data. The resulting wavefront data may be used to produce an enhanced image of the original image data. Example applications include remote sensors and targeting systems, and both passive imaging and active projection systems that compensate for wavefront anomalies.

The invention discloses a two-dimensional oscillating mirror scanned terahertz passive imaging system. The system realizes terahertz waveband imaging of an imaging sample by scanning gradually point by point by using a two-dimensional oscillating mirror and can adjust scanning speed, imaging time and optimum object distance of system imaging. The imaging system has the characteristics of high imaging space resolution ratio, high signal to noise ratio, high temperature resolution ratio and the like. Compared with the active type transmission and reflection terahertz imaging system, the system has the advantages of simple and compact structure, needs no local terahertz oscillating source and area-array detector, and merely needs unit detector.

The invention discloses an optical axis monitoring method and device for a high-precision active/ passive detection system. The device comprises a laser emission system, an optical axis separation assembly, a common telescope, an optical axis monitoring camera, a passive imaging system and a laser reception system. By utilizing a characteristic that an included angle between prism incident light and prism emergent light in an incident plane is only related to the an included angle of a prism reflecting surface, and by means of introducing an optical axis separation component and the optical axis monitoring camera and the like to the high-precision multi-optical axis active/passive composite detection system, a relative relation between a laser emission optical axis and a passive imaging system optical axis is established, so that variation conditions of each optical axis can be monitored in real time in the working process of the high-precision active/passive detection system, and on the basis of the obtained optical axis variation data, detection data can be corrected in the following data processing. The method and the device have the advantages of high optical axis monitoring sensitivity, good self optical axis stability and mature processing and adjusting technology and the like, and can be widely applied to an airborne and satellite-borne high-precision active/passive compound detection optoelectronic system.

A multimode pixel of a pixel array is provided. The multimode pixel includes a photodetector, an image sensing circuit having a first plurality of transistors, and a laser range finding (LRF) circuit having a second plurality of transistors. At least one transistor of the second plurality of transistors, but not all of the second plurality of transistors, is included in the first plurality of transistors. The LRF circuit being configured to perform LRF operations and the image sensing circuit is configured to perform passive imaging operations. The image sensing circuit and the LRF circuit are configured to perform concurrently.

The invention discloses a spacecraft relative navigation method based on generative reconstructed images. Because the sunlight in the aerospace environment of a spacecraft is parallel light, the lightradiation area and shade area of a target satellite under the sunlight radiation condition are strongly contrasted, and the target image obtained by a vision camera is not complete. The spacecraft relative navigation method comprises the following steps of using the information of a target local image obtained by the vision camera as input quantity; according to the preset satellite attributes, obtaining feature vectors through learning by a deep neural network; reconstructing the local image obtained by the vision camera into a complete image by a generative adversarial method; performing stereo solving on the generated complete image, so as to obtain relative position postures; converting the relative quantity into a spherical coordinate system as the measuring value of a navigation system; using a relative motion equation under the spherical coordinate system as a navigation state equation, and adopting a special filtration algorithm to complete the solving of the relative navigation. The spacecraft relative navigation method has the advantage that the relative navigation can be completed by passive imaging devices of vision camera and the like.

An automatic multi-beam laser active imaging alarm system relates to an all-weather remote imaging detection system and solves the problems that when adopting passive imaging, the traditional security device has low resolution ratio and the accurate resolution and recognition of small remote dark targets is difficult to realize, when the traditional security device adopts laser active imaging, the detection range of the traditional security device is less than 2km, and the image resolution of echoes collected by a receiving system is reduced as the optical spot scintillation effect causing lights beams leads the uniformity of target light spots to be reduced; and the whole system is jointly composed of a laser, a polarizing beam splitting system, a transmitting system, the receiving system, a CCD (Charge-Coupled Device) detector, an image collecting system and an automatic target recognition system. Finally, the automatic recognition and alarm on human body targets holding guns is realized. The automatic multi-beam laser active imaging alarm system provided by the invention is an automatic alarm system which can realize remote high resolution and high-intellectualized imaging.

The invention provides a three-dimensional composite imaging method of a hyperspectral laser, a system and an unmanned self-propulsion device. The method includes steps of scanning an underwater suspicious zone through hyperspectrum so as to determine a detecting target in a suspicious zone; scanning the detecting target through a laser, and acquiring a backward scattering signal; confirming the distance information with the detecting target through the backward scattering signal; preforming interference shielding treatment on intensity information, spectrum information, and polarization information of the backward scattering signal, and acquiring the position information of the detecting target after analyzing the distance information with the detecting target; according to the intensityinformation, spectrum information, and polarization information of the backward scattering signal after removing interference, generating a three-dimensional image of the detecting object. Through combination of active laser scanning and hyperspectral passive imaging, the polarization information and spectral information of the detecting target are extracted; through information fusion of the both, speciality inversion of the small underwater target is completed, thereby realizing the accurate identification and high-precision location of the detecting target under the water.

The invention discloses a system used for conducting on-line monitoring for pushed slab kiln inner wall surface condition. The system used for conducting the on-line monitoring for the pushed slab kiln inner wall surface condition comprises an active light source emitting device, a passive imaging receiving device and a central processing unit, wherein the active light source emitting device is arranged on the outer side of one end of the pushed slab kiln body and used for producing blue laser beams or green laser beams, and the laser beams penetrate through the kiln body in a manner of covering and lighting the whole pushed slab kiln inner wall surface after being processed through expansion shaping. The passive imaging receiving device is arranged on the outer side of the other end of the kiln body and used for receiving the laser beams from the kiln and producing corresponding detecting images. The central processing unit is used for conducting real-time judgment for the pushed slab kiln inner surface conditions according to the detecting images produced by the passive imaging receiving device, so that the monitoring of the pushed slab kiln inner wall surface condition is achieved. The system used for conducting the on-line monitoring for the pushed slab kiln inner wall surface condition is capable of achieving effective detection for the pushed slab kiln inner wall surface condition with the compact structure and the convenient operation. At the same time, the system has the advantages of being high in automation degree and detection precision, and suitable for on-line detection and the like.