238 results about "Light field imaging" patented technology

Methods and apparatus for light-field imaging. Light-field camera designs are described that produce higher spatial resolution than conventional plenoptic camera designs, while trading-off the light-field's angular sampling density. This lower angular resolution may be compensated for by a light-field image processing method that inserts data synthesized by view interpolation of the measured light-field. In one embodiment, a light-field image processing method that performs three-view morphing may be used to interpolate the missing angular samples of radiance. The light-field camera designs may be implemented in hand-held light-field cameras that may capture a light-field with a single exposure. Some of the light-field camera designs are internal to the camera, while others are external to the camera. One light-field camera design includes a single, relatively large lens and an array of negative lenses that are placed in front of (external to) the main lens of a conventional camera.

A compressed light field imaging system is described. The light field 3D data is analyzed to determine optimal subset of light field samples to be (acquired) rendered, while the remaining samples are generated using multi-reference depth-image based rendering. The light field is encoded and transmitted to the display. The 3D display directly reconstructs the light field and avoids data expansion that usually occurs in conventional imaging systems. The present invention enables the realization of full parallax 3D compressed imaging system that achieves high compression performance while minimizing memory and computational requirements.

Light field imaging systems, and in particular light field lenses that can be mated with a variety of conventional cameras (e.g., digital or photographic / film, image and video / movie cameras) to create light field imaging systems. Light field data collected by these light field imaging systems can then be used to produce 2D images, right eye / left eye 3D images, to refocus foreground images and / or background images together or separately (depth of field adjustments), and to move the camera angle, as well as to render and manipulate images using a computer graphics rendering engine and compositing tools.

This image capture device includes: an image sensor 2 including first and second types of pixels that have mutually different spectral transmittance characteristics; a light-transmitting section 1 that is arranged to face the imaging area of the image sensor 2; and an imaging section 3 that includes at least a first imaging area having a first focal length and a second imaging area having a second focal length that is longer than the first focal length. The light-transmitting section 1 has a first light-transmitting area 1a comprised of multiple partial areas that are separated from each other and a second light-transmitting area 1b having a different spectral transmittance characteristic from the first light-transmitting area 1a. The distance from the light-transmitting section 1 to the imaging section 3 is equal to the first focal length f1 and the distance from the imaging area of the image sensor 2 to the imaging section 3 is equal to the second focal length f2.

The invention provides an optical field imaging device and method. A device corresponding to the optical filed imaging method enables an image plane of a main lens to be overlapped with the a variable-zoom micro lens array through horizontally moving the main lens; the focal length of the variable-zoom micro lens array is an initial focal length, and the distance between a sensor and the variable-zoom micro lens array is equal to the initial focal length; a first image is obtained by the sensor and the main lens is horizontally moved to enable the image plane to be deviated from the position of the variable-zoom micro lens array; the focal length of the variable-zoom micro lens array is correspondingly adjusted to a second focal length so that the image plane of the main lens is conjugated and imaged on the sensor through the variable-zoom micro lens array to obtain a second image; in the process, the change of the horizontal movement position of the main lens and the focal length of the variable-zoom micro lens array abides by a Gaussian optical law; high-direction resolution rate information of the first image and high-direction resolution rate information of the second image are extracted through an extracting part; and an image processing part is used for carrying out weighting recombination on the extracted information and carrying out registration and reconfiguration on the image to obtain the best imaging effect.

Embodiments of 3D imaging systems that use a multifunctional, nano structured metalens to replace the conventional microlens array in light field imaging are disclosed. The optical focusing properties of the metalenses provided by gradient metasurface optical elements. The gradient metasurfaces allow the properties of the elements of the metalens array to be changed by tuning the gradient metasurfaces.

A relatively high-resolution image from a conventional camera can be computationally combined with a relatively low-resolution wavefront measurement from, for example, a Shack-Hartmann sensor in order to construct a relatively high-resolution light-field image.

Light field imaging systems, and in particular light field lenses that can be mated with a variety of conventional cameras (e.g., digital or photographic / film, image and video / movie cameras) to create light field imaging systems. Light field data collected by these light field imaging systems can then be used to produce 2D images, right eye / left eye 3D images, to refocus foreground images and / or background images together or separately (depth of field adjustments), and to move the camera angle, as well as to render and manipulate images using a computer graphics rendering engine and compositing tools. A doublet lenslet array element for use in light field imaging systems includes a first lenslet array element having a first plurality of lenslet array elements, and a second lenslet array element having a first plurality of lenslet array elements, wherein the first lenslet array element is coupled in close proximity to the second lenslet array element. The first and second lenslet array elements are glued together or otherwise bonded together and the first lenslet array element is made from a first optical material different than a second material forming the second lenslet array element.

An adjustable multimode lightfield imaging system. A non-homogeneous filter module is positioned at the pupil plane of the lightfield imaging system and provides the multimode capability. The filter module can be moved relative to the imaging system with the exposure conditions adjusted accordingly, thus allowing adjustment of the multimode capability.

The invention discloses a multispectral light-field imaging method. The adopted hardware comprises a wideband filter array, an isomerism camera array, a control panel array and an information joint processing device, wherein the wideband filter array, the isomerism camera array, the control panel array and the information joint processing device are arranged in sequence in the light path direction. The imaging method comprises the steps of placing wideband filters with different wavelengths among each camera lens and sensor of the isomerism camera array so that each camera in the isomerism camera array can receive spectral information with a fixed waveband ; using the information joint processing device to conduct stereo matching based on a convolutional neural network on multipath information obtained by the camera array to obtain angular information of incident ray and obtain optical field information within a full field range; conducting camera calibration and view field aligning on distribution positions of cameras, and obtaining multi-waveband spectral information of which the number is three times the number of cameras under any camera perspective in the camera array through spectral demultiplexing. According to the multispectral light-field imaging method, multispectral optical field information of each pixel with the full field range can be obtained simultaneously, and thus dynamic and united obtaining of optical field and spectral information is achieved.

The invention discloses a light field imaging automatic refocusing method. According to the method, a point spread function model and an ambiguity evaluation model are established, based on the models, according to different focusing depths and a corresponding refocusing image, an ambiguity evaluation function of an area of interest is estimated, the focusing depth of the area of interest is obtained by obtaining an extreme point of the function, and finally a refocusing image corresponding to the depth is obtained. By directly estimating the focusing depth of the area of interest, refocusing of the area of interest is achieved, the shortcoming that computing redundancy is large in the existing method is overcome, a quick and effective automatic refocusing mechanism is provided for optical field imaging in imaging field depth expanding, the execution efficiency of refocusing operation of the optical field imaging area of interest is improved, and studying, application and development of optical field imaging can be well promoted.

Compound eyes of insects are great optical system for imaging and sensing by the nature creator, which is an unsurpassed challenge due to its precision and small size. Here, we use meta-lens consisting of GaN nano-antenna to open the fascinating doorway to full-color achromatic light field imaging and sensing. A 60×60 multi-channels meta-lens array is used for effectively capturing multi-dimensional optical information including image and depth. Based on this, the multi-dimensional light field imaging and sensing of a moving object is capable to be experimentally implemented. Our system presents a diffraction-limit resolution of 1.95 micrometer via observing the standard resolution test chart under white light illumination. This is the first mimic optical light field imaging and sensing system of insect compound eye, which has potential applications in micro robotic vision, non-men vehicle sensing, virtual and augmented reality, etc.

The present invention provides a light field imaging-based chromatographic PIV measuring device and a method. The device includes a light source apparatus for generating double-pulse laser light and illuminating a three-dimensional flow field and an imaging apparatus for photographing the three-dimensional flow field; the light emitting end of the light source apparatus is provided with a lens group; the light source apparatus and the imaging apparatus are connected with a time sequence synchronous controller; the imaging apparatus is connected with a computer; the lens group is used for developing the double-pulse laser generated by the light source apparatus into a body light source of a certain thickness and a two-dimensional sheet light source of 1 mm and illuminating the flow field; and the image forming apparatus comprises a main lens, a CCD detector and a microlens array positioned between the main lens and the CCD detector. With the device and the method of the invention adopted, a weight matrix can be can quickly calculated, the calibration of the internal and external parameters of a light field camera is not required, and system error caused by multi-camera synchronous coupling can be reduced. The device is simple.

A structured light field three-dimensional imaging method is provided. The method includes acquiring a structure light field recorded by an imaging device of a structured light field three-dimensional imaging system, solving the phase of the structured light field, comparing the solved phase of the structured light field with a reference plane phase to acquire a phase difference, calculating a depth value of each light line by utilizing a phase-depth mapping relation of the structured light field, and constructing multi-direction three-dimensional imaging by utilizing a direction and the calculated depth value of each light line in the structured light field. The structured light field three-dimensional imaging system is also provided. The structured light field is acquired by combining light field imaging and structured lighting in the technical scheme. The mapping relation between the phase and a scene depth of the structured light field is deduced. One time of collection and multi-direction three-dimensional imaging can be achieved. The method and the system facilitate further research of structured light field three-dimensional imaging theories and applications and meet requirements on multi-view three-dimensional digital imaging and measurement.

The invention provides a light field imaging and printing device and a micro lens thin film with three-dimensional floating images, wherein the thin film is prepared by the light field imaging and printing device. The scanning operation on a lens surface is conducted by a scanning galvanometer system, and four-dimensional light field data can be printed in combination with the variation of space three-dimensional coordinates. The light field imaging and printing device comprises a light source, a scanning galvanometer system, a lens, a diffuser, a converging lens assembly and a micro lens recording material. Light rays sequentially pass through the scanning galvanometer system, the lens, the diffuser and the converging lens assembly, and then instantaneous and dynamic focus spots are outputted. In this way, a volumetric-pixel type radiation light field is obtained. After that, the information of the instantaneous volumetric-pixel type radiation light field is recorded by the micro lens recording material. By means of the device and the thin film, more realistic three-dimensional dynamic images can be formed. Through controlling different variable values, floating images of multiple different characteristics are formed. Therefore, the multi-view imaging effect of varying images can be realized.

The invention relates to a digital focusing method and a digital focusing device used for optical field imaging. The method comprises the following steps: selecting a window range of a target from a two-dimensional optical field image, and extracting optical field data in the window range; according to different focusing parameters, performing target image reconstruction to obtain an image sequence; and performing image definition evaluation on the image sequence, and finding an optimal focusing parameter value so as to obtain a refocusing image with optimal target definition. The method and the device reduce quantity of data participating in the image reconstruction, thereby saving time for digital focusing.

Light field imaging systems, and in particular light field lenses that can be mated with a variety of conventional cameras (e.g., digital or photographic / film, image and video / movie cameras) to create light field imaging systems. Light field data collected by these light field imaging systems can then be used to produce 2D images, right eye / left eye 3D images, to refocus foreground images and / or background images together or separately (depth of field adjustments), and to move the camera angle, as well as to render and manipulate images using a computer graphics rendering engine and compositing tools.

The invention discloses a color and depth imaging method based on structured light and light-field imaging. The method comprises steps as follows: a light field image of a preset shoot scene to be shot by a user is acquired; the acquired light field image is subjected to scene analysis, and a specific scene type of the preset shoot scene is acquired; a corresponding mode of structured light of the preset shoot scene is acquired and shot to the preset shoot scene according to the relation between different preset screen types and structured light in different modes; a depth image of the preset shoot scene under radiation of the structured light is acquired; color images and depth images in the light field image are extracted and processed and fused together with the depth image, and a comprehensive image with color and depth for the preset shoot scene is finally acquired. According to the color and depth imaging method based on structured light and light-field imaging and a device used for the method, an active and inactive combined depth imaging mode is adopted, an active depth imaging mode and an inactive depth imaging mode complement each other's advantages, color and depth imaging is realized, and the imaging quality is guaranteed.

The invention provides a light field imaging system. The light field imaging system comprises a microlens array, a light beam guiding unit, an imaging unit and an image processing unit, wherein the microlens array comprises a plurality of microlens units used for focusing light beams; the light beam guiding unit is used for guiding the light beams imaged through the microlens array so as to enable light having a larger included angle with a light axis of the light field imaging system to be transmitted to the imaging unit through the microlens array; the imaging unit is arranged on a focal plane of the microlens array and is used for receiving light transmitted by the microlens array so as to carry out light sensitive imaging; and the image processing unit is used for processing electric signals collected by the imaging unit. According to the invention, the light field imaging system is simple in structure and is capable of collecting light with a larger view angle for light field imaging, so that the view field angel of the light field imaging system is effectively enlarged.

The invention discloses a device and a method for detecting surface defects on a strip steel. The method includes following steps: arranging a plain mirror on a to-be-detected surface of the strip steel or a thick plate, wherein the plain mirror and the to-be-detected surface are arranged at a certain angle so that the to-be-detected surface can images on the plain mirror; calculating an imaging distance of the to-be-detected surface; arranging a camera according to the imaging distance; illuminating the plain mirror through an illumination source to enable the plain mirror to satisfy a light field imaging condition and a dark field imaging condition; and photographing an image, on the plain mirror, of the to-be-detected surface of the strip steel through the camera. By means of the technical scheme of the invention, influence of a narrow and small space on a surface quality detection system is overcome. Spaces on an upper surface and a lower surface of the strip steel can be fully utilized. Influence of a poor environment on a lower-surface detection camera can be avoided. Detection effects on each surface of the strip steel can be improved.

The invention discloses a light field imaging device and a parameter determination method thereof. The light field imaging device comprises an imaging main lens, a microlens array and an imaging information acquisition photosensitive CCD, which are arranged in parallel in sequence. The microlens array comprises a plurality of microlenses arranged in the same plane; and the entrance pupil surface side of the imaging main lens is closely connected with orthogonal defocus gratings for imaging light field information in different depth ranges to different regions of the microlens array. The parameter determination method comprises the following steps: dividing the microlens array into imaging acquisition sub-regions; selecting focal length and aperture of the imaging main lens; determining system equivalent focal length of the different imaging acquisition sub-regions and off-axis magnitude of the orthogonal defocus gratings; determining stripe parameters of the orthogonal defocus gratings; and selecting parameters of the microlens array. The light field imaging device has the advantages of high imaging resolution, large depth extraction dynamic range, wide application range, simple structure and low cost.

The invention relates to an angular super-resolution reconstruction method on the basis of perception loss for images of light fields, and belongs to the field of light field imaging. The angular super-resolution reconstruction method includes that mean square errors of image high-dimensional features extracted by pre-training models are used as loss functions, a network model which comprises fourresidual blocks is built, nonlinear mapping relations between observation images and target viewing angle images are learned, and accordingly new viewing angle images can be reconstructed. The angular super-resolution reconstruction method has the advantages that the perception loss for expressing the high-dimensional features is introduced, accordingly, texture details of the super-resolution reconstructed new viewing angle images can be effectively kept, and excellent visual effects can be realized by the angular super-resolution reconstruction method.

The invention discloses a light-field imaging method for a programmable aperture microscope system based on an LCD panel. The light-field imaging method is implemented by a microscopic imaging system and a 4f system of the LCD panel, and comprises the steps of: acquiring light field subimages; determining focal lengths z which need to be calculated; conducting circulating translation on the M light field subimages acquired in the first step according to a rule; and correspondingly adding the obtained light field subimages obtained after translation according to pixels to obtain a reconstructed image with a focal length (imaging depth) at z. The light-field imaging method can achieve full resolution light-field imaging, does not have a problem of contradiction between spatial resolution and angular resolution in the traditional light-field imaging, can flexibly achieve the effect of focusing after photographing, and can directly obtain sample images of different depths through calculation without moving an object stage of the sample.

A depth of field imaging apparatus includes a light field imager and a time of flight imager combined in a single on-chip architecture. This hybrid device enables simultaneous capture of a light field image and a time of flight image of an object scene. Algorithms are described, which enable the simultaneous acquisition of light field images and a time of flight images. Associated hybrid pixel structures, device arrays (hybrid imaging systems), and device applications are disclosed.

The invention discloses a light field imaging device based on digital coding control. The light field imaging device comprises a main lens, a digital coding element, a micro-lens array, a sensor and a logic control unit, wherein the main lens is used for converging object space light beams, the digital coding element is used for digital modulation of incident light, the micro-lens array is used for extracting light field information, the senor is used for forming light field images, and the logic control unit is used for controlling the sensor and the digital coding element. By the aid of digital modulating action of the digital coding unit on the incident light, limit of traditional light field imaging to F number matching requirement of the main lens is broken through. Angular resolution of light field imaging is improved while spatial resolution of light field images is also guaranteed, and light field imaging application flexibility and imaging quality are improved beneficially.

The invention discloses a method for generating a full-focus image of a light field based on a depth map, belongs to the field of light field imaging, and solves a problem that a block effect and an edge effect exist in multi-image fusion realized by adopting an algorithm such as DCT and wavelet transform in a traditional full-focus image generation process. The method adopts a defocusing image obtained by a light field camera to generate the full-focus image, and specifically comprises the following steps of (1) micro-lens calibration; (2) 4D light field acquisition; (3) digital refocusing; (4) depth acquisition and (5) full-focus image generation. The method has the advantages that the limitation of a fusion algorithm in the traditional full-focus image generation process is avoided, a focusing area of the defocusing image can be accurately found out to carry out full-focus image generation, and meanwhile, the method is superior to the wavelet transform and the DCT transform on the block effect and the edge effect.

The invention discloses a calibration method of a coupling position relationship between a micro lens array and a detector. The calibration method of the coupling position relationship between the micro lens array and the detector includes: combining a device formed by coupling the micro lens array and the detector with a front optical system into a light field imaging system; building a mapping equation between the center of micro lenses and a point pi,j on a plane of the detector based on a central projection principle; using a parallel light source to confirm a rough distance between a main lens and the micro lens array; using a uniform area light source to calibrate the light field imaging system, and confirming an actual coordinate of the point pi,j on the plane of the detector; confirming accurate value of L1; using an optimization algorithm to estimate coupling error angles phi, omega, k and d between the micro lens array and the detector. The calibration method of the coupling position relationship between the micro lens array and the detector only needs to roughly confirm a position relationship between the micro lens array and the front optical system in the light field imaging system, cam achieve calibration of parameters of a distance, a rotation angle and the like between the micro lens array and the detector, is simple to use, and facilitates actual operation.

The invention discloses a light field camera refocusing method based on orthogonal lattice point conversion. Firstly, a light field camera is used for shooting a uniform white wall or a uniform whitelight plate to obtain a white image, an inter-class variance method is used for solving an optimal threshold value of the white image and carrying out binaryzation, and a hexagonal-orthogonal latticepoint conversion method is used for correcting a white image contour area; on the basis, two-dimensional coordinates of a central point of a white image contour are calculated by using image invariantmoment, four-dimensional information of a light field is represented by using a biplanar parametric representation method, and finally, refocusing of the light field image is realized by using a light field imaging principle and an energy function of light. The refocused image is rich in details and high in calculation efficiency, can be used as an image post-processing algorithm to stably operate in the current infrared monitoring equipment, and improves the scene depth information collected by the current equipment.