176 results about "Modulation transfer" patented technology

A method for evaluating edge quality in an image includes receiving an image from a camera of a vehicle, detecting an edge in the image captured by the camera, fitting a polynomial curve to the edge in the image captured by the camera, executing a numerical optimizer to determine a minimum distance from each pixel in the image of the edge to the polynomial curve, determining a modulation transfer function (MTF) value using the minimum distance, determining whether the MTF value is greater than predetermined threshold, and providing an alert in response to determining that the MTF value is not greater than the predetermined threshold.

The invention provides an ocean vortex region one-dimensional wave spectrum inversion method based on a synthetic aperture radar, and the method comprises the steps: recognizing an ocean vortex through HY-2 fusion data, collecting a Sentinel-1 dual-polarized SAR image covering a vortex region, and obtaining WAVEWATCH-III wave mode data; a hydrodynamic modulation transfer function is improved, and a vortex shear flow influence factor is introduced; an XGBoost machine learning model is adopted, and an ocean vortex region SAR one-dimensional sea wave spectrum inversion algorithm is established; and verifying the accuracy of the SAR one-dimensional sea wave spectrum inversion algorithm. According to the method, the precision limitation of traditional wave theory inversion in a vortex region is broken through, and the one-dimensional wave spectrum inversion precision is improved.

A protective barrier affixable to a curved substrate comprises a stack of two or more lenses, each of the two or more lenses including a polyethylene terephthalate (PET) film, a hard coat on a first side of the PET film, and an adhesive layer on a second side of the PET film opposite the first side. The stack of two or more lenses may have a modulation transfer function that exhibits a contrast value greater than 75% for a spatial resolution of one line-pair per 0.0003 radians at 65 degrees angle of incidence. Heat and pressure may be applied to conform the stack of two or more lenses to the shape of the curved substrate.

The invention provides an optical imaging lens. The optical imaging lens comprises a lens barrel, a lens group and a spacing assembly, and the lens group is composed of six lenses. The six lenses are sequentially a first lens with negative focal power, a second lens with focal power, a third lens with positive focal power, a fourth lens with negative focal power, a fifth lens with positive focal power and a sixth lens with negative focal power from the object side to the image side along the optical axis of the optical imaging lens; the following conditions are satisfied: 4.20 lt; l / (T45 + T56) lt; 4.95 DEG C, 4.95 DEG C; the following conditions are satisfied: 1.15 lt; f5 / d5slt; 1.65, 1.65; the following conditions are satisfied: 7.00 lt; (D5s-d4s) / EP45lt; and 11.90, 11.90. The optical imaging lens solves the problems that in the prior art, an air gap between adjacent lenses located at the image side end of a six-piece type optical imaging lens is large, the light ray progress is prone to being affected, and then the out-of-focus curve of a modulation transfer function deviates and the peak value is reduced.

The invention belongs to the technical field of eye vision optics, and relates to a microstructure optical imaging element design method and a microstructure optical imaging element, and the method comprises the steps: building a microstructure lens three-dimensional model under different rise variations based on the structure parameters of a mother lens and the structure parameters of a negative microlens array under different rise variations; acquiring modulation transfer function curves of the optical system containing the three-dimensional models of the microstructural lenses and spatial frequencies of first minimum value points on the modulation transfer function curves; fitting the spatial frequencies of all the first minimum value points and the corresponding rise variations to obtain a relation equation of the spatial frequencies of the minimum value points and the rise variations; based on the relation equation of the spatial frequency of the minimum value point and the rise variation, the spatial frequency limit value when the imaging contrast of the microstructure lens is lower than the preset minimum contrast when the rise variation is infinite is obtained, so that the threshold value range of the rise variation is obtained, and a theoretical basis is provided for the design of the microstructure lens based on negative refractive power.

The invention discloses an SAR (Synthetic Aperture Radar) image MTF (Modulation Transfer Function) quality evaluation method and system based on a natural scene edge, and the method comprises the steps: building a selection standard system for automatic edge screening of a natural scene SAR image, and determining a high-contrast linear edge according to the standard system; automatically detecting a high-contrast linear edge in the natural scene, and intercepting a region of interest for subsequent calculation based on the position of the linear edge; gray level distribution is extracted in the normal direction of the linear edge, and an edge spread function is constructed and used for describing gray level transition response of the imaging system in the edge area; carrying out normalization and smoothing processing on the edge spread function, and carrying out spatial domain first-order differential calculation to obtain a line spread function; and performing fast Fourier transform on the line spread function to obtain a modulation degree transfer function curve, and representing the detail transfer capability of the system under different spatial frequencies. According to the method, the imaging quality of the SAR image of the natural scene can be automatically, accurately and quantitatively evaluated under the condition that manual field arrangement is not needed.

A protective barrier affixable to a curved substrate comprises a stack of two or more lenses, each of the two or more lenses including a polyethylene terephthalate (PET) film, a hard coat on a first side of the PET film, and an adhesive layer on a second side of the PET film opposite the first side. The stack of two or more lenses may have a modulation transfer function that exhibits a contrast value greater than 75% for a spatial resolution of one line-pair per 0.0003 radians at 65 degrees angle of incidence. Heat and pressure may be applied to conform the stack of two or more lenses to the shape of the curved substrate.

The invention provides an optical imaging apparatus. The optical imaging device comprises a lens barrel, a lens group and a spacing element group, and the lens group and the spacing element group are assembled in the lens barrel. The five lenses are sequentially a first lens with negative focal power, a second lens with positive focal power, a third lens with positive focal power, a fourth lens with negative focal power and a fifth lens with positive focal power from the object side to the image side; the spacing element group comprises a first spacing element; the following conditions are satisfied:-2.18 lt; f1 / flt; -1.40,-1.40,-1.40; the following conditions are satisfied: 1.61 lt; t12 / CP1lt; 2.22, 2.22; the following conditions are satisfied: 3.50 lt; d1s / R2lt; and 5.45. The five-piece type optical imaging device solves the problems that in the prior art, a five-piece type optical imaging device controls the focal length and the distance of a front-end lens, so that a defocus curve of a modulation transfer function is discrete, and the peak value is low.

The invention relates to the technical field of laser, in particular to a high-signal-to-noise-ratio modulation transfer spectrum frequency stabilization light path system. The system comprises a laser, an optical isolator, a first half-wave plate, a first polarization splitting prism, an optical fiber coupler, a second half-wave plate, a second polarization splitting prism, a first reflecting mirror, an electro-optical modulator, a second reflecting mirror and a third polarization splitting prism, wherein the first half-wave plate is used for adjusting the power of frequency stabilization light; the second half-wave plate is used for adjusting the power ratio of pump light to probe light; a first quarter-wave plate, a second quarter-wave plate, an atomic gas chamber and a photoelectric detector; after the output of the laser is isolated by the optical isolator, the first half-wave plate and the first polarization splitting prism are matched to adjust the frequency stabilization total beam power to about 5mW; the pump light is modulated by the electro-optical modulator, the probe light and the pump light reversely interact in the atomic gas chamber in an anti-phase circular polarization state, and the signal-to-noise ratio of a modulation transfer signal and the stability of a frequency stabilization system are remarkably improved.

The invention relates to the technical field of error detection of telescopes, in particular to a spliced telescope sub-mirror co-phase error detection method, which comprises the following steps of: firstly, designing a special mask, so that secondary peak values for representing sub-mirror co-phase errors in an MTF (Modulation Transfer Function) under wide-spectrum illumination are not overlapped; therefore, real secondary peak values representing co-phase errors of all sub-mirrors in the MTF under wide spectrum illumination can be calculated respectively; initializing a population optimization algorithm, taking an initial solution as a sub-mirror co-phase error under a certain condition, substituting the initial solution into the spliced telescope simulation model, calculating to obtain a simulation sub-peak value representing the sub-mirror co-phase error, and taking a variance between the simulation sub-peak value and a real sub-peak value as an evaluation index; and the optimal simulation quantity is selected according to the evaluation indexes, and repeated iteration is carried out, so that large-range high-precision real-time detection on the three-dimensional co-phase error of each sub-mirror is realized.

A technique is disclosed for analyzing and displaying the extent to which the images and structures inferred by a physically seeded multiscale network correspond to genuine resolution improvement through noise insensitive point spread function deconvolution, and the extent to which they correspond to the hallucination of realistic looking structures with realistic frequency contents. A relative modulation transfer function can be computed, which can represent the distribution of frequency components in a particular reconstruction (e.g., a volumetric reconstruction from high-resolution data) that are not robustly recovered by a different reconstruction (e.g., a volumetric reconstruction via processing of low-resolution data with a trained neural network). The high-frequency portion of these frequency components can represent hallucinations introduced by a trained neural network, and can be leveraged to filter the different reconstruction prior to further use.

The invention relates to the technical field of vehicle-mounted equipment testing devices, and discloses a vibration test evaluation method and device suitable for a long-focus wide-angle vehicle-mounted camera, a plurality of cameras to be tested are installed on a six-degree-of-freedom vibration table in a darkroom, and a position-adjustable test chart card and a light source system are arranged in front of the cameras; the driving module is adopted to lighten the camera, so that remote controllable shooting is realized; configuring a test environment, and adjusting parameters such as a graphic card position and illumination; driving a camera to shoot an image card under multiple working conditions, outputting an original image sequence, and driving a module to complete a traversal test; the driving module returns a shooting result to the image analysis module, and the image analysis module analyzes imaging quality in real time, evaluates indexes such as a modulation transfer function and motion blur, and generates a multi-dimensional optical performance report; generating a multi-degree optical dimension performance report of the camera; the technical problem that a real vehicle multi-degree-of-freedom direction vibration coupling scene cannot be simulated in the prior art is solved.

A diffraction grating includes a plurality of diffraction features and a plurality of grooves. Each groove of the plurality of grooves is adjacent to at least one diffraction feature of the plurality of diffraction features. One or more apodization features include apodization by a varied ratio of the filled region of one or more diffractive gratings to the total period, typically known as the grating fill factor to a gradually alter one or more edges of the plurality if diffraction features of at least one optical element of a waveguide. The one or more apodization features reduce a diffraction efficiency of at least one diffraction order of the diffraction grating.

The invention provides a laser frequency stabilization device and method based on optical frequency shift, and relates to the field of laser frequency stabilization, and the device comprises a first slave laser, a first frequency stabilization system, a second slave laser, a second frequency stabilization system, a master laser, an acousto-optic modulation module, and a phase-locked frequency stabilization device. The first slave laser is used for emitting first laser of a first wavelength; the main laser is used for emitting third laser with a second wavelength; the first frequency stabilization system is used for locking the first laser according to the first laser to obtain first frequency-stabilized laser; the second slave laser is used for emitting second laser with the first wavelength; the second frequency stabilization system is used for locking the second laser to obtain second frequency-stabilized laser; the acousto-optic modulation module is arranged between the first slave laser and a light path of the phase-locked frequency stabilization equipment; and the phase-locking frequency stabilization equipment is used for receiving the first frequency stabilized laser and the second frequency stabilized laser and carrying out frequency locking on the third laser according to the first frequency stabilized laser and the second frequency stabilized laser. According to the invention, the modulation transfer spectrum and the optical frequency shift can be combined to complete frequency locking of the laser.

Fluorescence imaging system designs are described that provide larger fields-of-view, increased spatial resolution, improved modulation transfer and image quality, higher spatial sampling frequency, faster transitions between image capture when repositioning the sample plane to capture a series of images (e.g., of different fields-of-view), and improved imaging system duty cycle, and thus enable higher throughput image acquisition and analysis for genomics and other imaging applications.

An apparatus for automatic lens focusing in a camera for one or more images is provided. An apparatus includes a platform to receive a lens holder mounted on an image sensor. The lens holder includes the lens to form images of a target object on the image sensor. The apparatus includes a lens adjusting unit including fixed rollers and a driver roller. The fixed rollers and the driver roller are to establish a contact with the lens. The driver roller is to rotate to turn the lens to adjust parameters of the images. The apparatus includes a control unit to compute a modulation transfer function value based on the images of the target object received from the image sensor. The control unit is to compare the modulation transfer function value with a predefined threshold to generate driving signals to rotate the driver roller.

The invention discloses a high-integration-level atomic spectrum device and method with stable laser system frequency for Rydberg atom preparation, relates to the technical field of atomic spectrum frequency stabilization, and aims to solve the problems of low integration level, heavy weight, poor robustness and the like in the prior art and improve the integration level, reliability and practicability of the atomic spectrum device. The device comprises a laser spectrum atomic gas chamber; the laser spectrum atomic gas chamber comprises two cavities, and the end face of one cavity is connected with a modulation transfer spectrum saturated light input optical fiber, a modulation transfer spectrum detection light input optical fiber and a modulation transfer spectrum detection light output optical fiber. And the end face of the other cavity is connected with an EIT spectrum coupling light input optical fiber, an EIT spectrum detection light input optical fiber and an EIT spectrum detection light output optical fiber. The integration level, reliability and practicability of the atomic spectrum device can be improved, and the modulation transfer spectrum and the EIT spectrum can be obtained in a non-interference mode at the same time.

The invention discloses a partitioned scattering optical lens for myopia control and a design method of the partitioned scattering optical lens, which are applied to the technical field of optics, and aims to solve the problem that the central visual quality and the peripheral myopia control effect cannot be considered at the same time in the prior art, the optical lens comprises a central optical region, a peripheral optical region and a smooth transition zone, the central optical area is low in scattering coefficient and high in MTF, a high modulation transfer function and low scattering loss are achieved, the peripheral optical area is high in scattering coefficient and low in MTF, the central optical area is used for inducing peripheral myopic defocus, the smooth transition area is used for achieving continuous gradual change of the scattering coefficient, visual sudden change is avoided, and visual comfort is ensured. The design method comprises the steps of eye parameter acquisition, optical performance target definition, microstructure design and simulation optimization, through the scheme, effective decoupling of central vision and peripheral myopia control is achieved, high-definition vision is ensured, myopia progress is restrained, and wearing comfort is improved.

The invention belongs to the field of NED equipment detection, and particularly discloses an NED equipment detection method and device, and the method comprises the steps: obtaining display pictures of NED equipment in different view fields through an NED detection device, thereby obtaining a modulation transfer function MTF1 in the meridian direction of each view field of the display pictures and a modulation transfer function MTF2 in the sagittal direction of each view field of the display pictures, the NED device comprises a near and far vision correction layer and / or an astigmatism correction layer; at least one of the spherical diopter, the cylindrical diopter and the azimuth angle of the optical axis of the liquid lens is adjusted until the MTF1 and the MTF2 are both not smaller than a preset MTF threshold value, and the NED detection device comprises the liquid lens; determining parameters of a correction layer of the NED based on the adjusted parameters of the liquid lens; and / or obtaining a picture displayed by the NED equipment by using the adjusted NED detection device, and carrying out picture quality detection. According to the invention, the NED equipment can be detected more efficiently and accurately, the production efficiency and the product quality are improved, and the detection cost is reduced at the same time.

The invention discloses an image definition evaluation method. The method comprises the following steps: acquiring an original image and an optical modulation transfer function; based on the original image and the optical modulation transfer function, generating a multi-scale baseline definition response set, an information-physical definition kernel, an uncertainty measure and an evidence vector; estimating a failure posterior probability based on the evidence vector; generating a gating weight based on the failure posterior probability and the uncertainty measure; and applying the failure posterior probability and the gating weight to execute failure posterior coupling processing on the multi-scale baseline definition response set and the information-physical definition kernel to generate a final definition evaluation result. The coupling process preferably includes applying analytic bias correction and performing cross-scale band selection. According to the method, the evaluation robustness in a complex scene is improved through a failure posterior coupling mechanism.

The invention provides a hyperspectral imaging system. The hyperspectral imaging system comprises a telescope group, a collimator objective, a prism, a volume holographic diffraction grating, an imaging objective and an imaging sensor which are arranged in sequence, the telescope group is composed of a primary reflector, a secondary reflector, a third reflector, a plane reflector and an entrance slit; the primary reflector, the secondary reflector and the third reflector form an off-axis three-reflector structure; the plane reflector is used for folding a light path; the collimating objective lens, the prism, the volume holographic diffraction grating, the imaging objective lens and the imaging sensor form an imaging spectrometer, and an entrance slit is used as object space input; the formed off-axis three-mirror and folded light path and an imaging spectrometer are in coaxial butt joint by taking an entrance slit as a node, and are used for joint correction and splicing to form a hyperspectral imaging system. According to the optical path architecture, optimal matching of the unobstructed total reflection front end and the transmission type rear end is realized, and the detection sensitivity of crop weak spectrum signals is greatly improved while a better modulation transfer function of a full view field is ensured.

The invention discloses a quantitative detection method for anti-perspective performance of a textile in a complex light environment, and belongs to the technical field of new material detection, a micro gap is arranged between the textile to be detected and a variable-frequency gray scale target to simulate a non-clinging state when clothes are worn and excite Fresnel diffraction and subsurface scattering effects, and the anti-perspective performance of the textile is detected. Complex illumination conditions such as backlight and sidelight are simulated by adjusting the light intensity ratio, and after a target perspective image is acquired by using an image acquisition unit, the modulation transfer function attenuation rate of a to-be-detected textile to the target is calculated, so that the anti-perspective performance of the textile is quantitatively represented; the interference of glare on the surface of the high-gloss fabric is effectively eliminated by introducing an orthogonal polarization modulation technology, and a detection result is highly consistent with the visual perception of human eyes by adopting a specific light source spectrum simulating the skin color of a human body; compared with a traditional light transmittance method, the method has the advantages that the dimension crossing from luminous flux measurement to image information fidelity evaluation is realized, and the accuracy, reliability and practicability of detection are remarkably improved.

The present invention discloses an evaluation method, device, computer equipment and medium for the optical depth of field of an endoscope. The evaluation method for the optical depth of field of an endoscope comprises: respectively obtaining image space resolution and local distortion rate at different working distances; calculating object space resolution at different working distances according to the image space resolution and local distortion rate at different working distances, wherein the calculation formula of the object space resolution is object space resolution=image space resolution×distortion rate; wherein the method for obtaining image space resolution at different working distances comprises: adjusting an endoscope body or a star image target so that the endoscope body is perpendicular to the star image target, and an imaging surface of an imaging device of the endoscope body is arranged parallel to the star image target; changing the working distance between the endoscope body and the star image target, and collecting images of the star image target at different working distances; and analyzing the collected images of the star image target at different working distances to obtain modulation transfer function data, namely, image space resolution.

Fluorescence imaging system designs are described that provide larger fields-of-view, increased spatial resolution, improved modulation transfer and image quality, higher spatial sampling frequency, faster transitions between image capture when repositioning the fields-of-view, improved imaging system duty cycle and a more compact system, and thus enable higher throughput image acquisition and analysis for genomics and other imaging applications at a lower cost.

The application relates to the technical field of atomic clocks, and provides a chip optical clock based on a modulation transfer spectrum principle and an implementation method thereof. The chip optical clock comprises: an on-chip narrow-line-width laser for emitting laser; a waveguide beam splitter for splitting the laser into two beams; one beam of laser is used for inputting into an electro-optic phase modulator, and the other beam of laser is used for inputting into a MEMS atomic cell; the electro-optic phase modulator is used for phase-modulating the one beam of laser and outputting pump light; the MEMS atomic cell is used for modulating and transferring the other beam of laser based on the pump light to obtain a probe spectrum; a photoelectric detector is used for converting the detected probe spectrum into an electric signal; a high-speed servo feedback control integrated circuit is used for converting the received electric signal into a feedback control signal, inputting the feedback control signal into a feedback control port of the on-chip narrow-line-width laser, realizing full-bandwidth locking, and outputting an optical clock signal. The above-designed chip optical clock has small integration difficulty and is easy to realize full-chip optical clock.

This invention discloses a high signal-to-noise ratio modulation transfer frequency stabilization optical path device, including a light source and a frequency stabilization optical path. The light source adopts an internally adjustable fiber collimator, with a 45° reflector behind it. The frequency stabilization optical path behind the 45° reflector includes a half-wave plate and a polarizing beam splitter (PBS). An atomic gas cell and two pyramidal reflectors are sequentially arranged on the probe light path of the PBS. A half-wave plate, a 45° reflector, an electro-optic modulator, another 45° reflector, and a half-wave plate are sequentially arranged on the pump light path. The polarizing beam splitter (PBS) is located at the convergence point of the two optical paths, and a 45° reflector, a frequency stabilization optical path lens, and a photodetector are sequentially arranged behind it. This invention cleverly utilizes a folded optical path design and fine-tunes the beam divergence angle to increase the length and area of ​​the laser-atomic interaction without increasing the system volume. At the same time, it actively controls the splitting ratio of the two frequency-stabilized beams, improving the stability of the frequency stabilization.

The invention belongs to the technical field of optical system detection, and provides a multi-view-field modulation transfer function measurement method and system based on feature recognition, and the method comprises the steps: collecting an image containing a feature target, determining an imaging position of the feature target on a detector through a feature recognition algorithm, and building a mapping relation between the imaging position and a view field of a to-be-detected optical system, determining a cutting area, transmitting image data into a modulation transfer function calculation algorithm for calculation, obtaining a modulation transfer function calculation result at a specific field of view based on a single static picture, and obtaining a plurality of calculation results of modulation transfer functions at different fields of view by continuously changing the relative position between the optical system and the to-be-measured target. And based on the modulation transfer function at the known field of view, utilizing an interpolation algorithm to obtain modulation transfer function data at other specific fields of view. According to the invention, the field-of-view position of the target to be analyzed in the measurement optical system can be accurately determined, the system structure is greatly simplified, and the construction cost of the test system is reduced.

An image sensor pixel includes a light sensor disposed in a semiconductor substrate. To provide isolation to reduce inter-pixel crosstalk and increase a modulation transfer function (MTF), an etch stop layer is disposed on a first surface of a semiconductor substrate, and a deep trench is etched on a second surface opposite the etch stop layer disposed on the first surface. Etching is stopped at the etching stop layer, and the bottom surface of the etching deep groove is the surface of the etching stop layer. At least one dielectric layer may be deposited on sidewalls and a bottom surface of the deep trench, and the remainder of the deep trench is filled with a metal or other opaque material. An image sensor pixel includes a semiconductor substrate and a photodiode disposed therein, and a metal barrier passing through the semiconductor substrate and arranged to provide optical isolation of the photodiode.

The invention relates to the technical field of distortion correction, and discloses a laser imaging wavefront distortion correction system and method based on deep learning, and the system comprises a first module which collects three intensity images; the second module is used for estimating the Zernike coefficient and the amplitude of the target complex amplitude; the third module is used for constructing a loss function; a fourth module that calculates an actuator voltage; the fifth module is used for calculating the Stell ratio and the high-frequency lifting ratio in the modulation transfer function; and the sixth module is used for re-applying the voltage of the actuator when judging that the evaluation condition is not met. According to the method, a full-process correction mechanism is constructed by integrating deep learning and an optical physical rule, and initial correction is realized by stably solving the voltage of the actuator by utilizing Tagunov regularization, so that the high-frequency detail definition in imaging is improved, the correction accuracy, real-time performance and robustness are both considered, and the method is suitable for large-scale popularization and application. And the application suitability of the laser imaging technology in the high-precision field is greatly expanded.

The invention relates to a myopia prevention and control contact lens based on a modulation transfer function area distribution method, and belongs to the technical field of optical design. Then adding an aspheric coefficient to optimize the imaging quality of each region; substituting into an area distribution method based on a modulation transfer function to obtain the area of each ring belt; determining whether the imaging quality of each area is equal or not, and if not, repeating the previous step; and finally, obtaining the myopia prevention and control contact lens based on the modulation transfer function area distribution method, wherein the imaging quality of each region is equal. According to the out-of-focus soft corneal contact lens, the proportion of an out-of-focus area and a correction area of a myopia prevention and control area is divided through an area distribution method of a combined modulation transfer function, so that the myopia prevention and control effect and the imaging quality are balanced, different refractive correction degrees are designed in different areas, a part of light is focused in front of the retina, and the myopia prevention and control effect is improved. Therefore, the visual axis is guided to change towards the health state, and the effect of preventing and controlling myopia is achieved.