8 results about "Fourier phase" patented technology

The application discloses a multi-height lensless holographic microscopic image registration method based on frequency domain and space domain combination. Firstly, a Fourier phase correlation method is used to find a correlation peak value to coarsely calibrate a space translation error; then, for the coarsely corrected hologram, a method for quickly and accurately searching a matching feature point in a space domain is provided to obtain an accurate scaling factor, an image morphological technology is used, and the sample itself is used as the feature point, so that any marking on the sample is not needed; after the image scaling calibration is completed, the Fourier phase correlation method is used again to perform accurate translation calibration. Compared with the existing registration algorithm, the application can more accurately and quickly register and align the multi-height lensless holographic microscopic images.

The application provides an electric field tomography detection system and method with adjustable electrode plate distance, which comprises a cylindrical shielding layer (1), a plate electrode array (2), a control module (3), a sinusoidal excitation voltage module (4), a multi-channel electronic switch module (5), a stepping motor transmission module (6), a voltage detection module (7), a Fourier phase extraction module (8) and an electrical impedance tomography module (9). The stepping motor transmission module (6) can accurately move the electrode plate to a suitable position, and the Fourier phase extraction module (8) is used for fast Fourier transform to simplify the phase offset calculation in the electric field tomography system. The application solves the problem of fixed electrode plate in the electric field tomography detection system, and the high accuracy of the stepping motor can accurately adjust the positions of the plate electrode array and the target object, which is beneficial to signal detection.

The application provides a hyperspectral super-resolution reconstruction method and system fusing phase priori and degradation perception, the method comprising: acquiring an observed image and a spectral response function matrix, and constructing an optimization objective function comprising a data fidelity term and a space-spectrum joint priori term; using a semi-quadratic splitting algorithm to decouple the objective function into three constraint terms of physical fidelity, spectral low rank and depth priori; using a Fourier phase-amplitude mixed processing model, a truncated singular value decomposition model and a double-branch proximal mapping network model to optimize and solve the three constraint terms respectively, to obtain and update a first auxiliary variable, a second auxiliary variable and a target hyperspectral image; through cyclic iteration until the iteration number reaches a number threshold, the target hyperspectral image output in the last iteration cycle is taken as a high-resolution hyperspectral reconstruction image. The application effectively improves the spatial texture recovery capability and spectral fidelity of the image.

It is provided a method for encoding complex data. The method includes the steps of: obtaining an input signal made up of a series of numerically represented samples; determining a time frame of the input signal to process; applying a first window function on data in the time frame, resulting in first windowed data, wherein the first window function tapers sample magnitude towards the edges of the first window function; performing a windowed complex discrete Fourier-related transform on the first windowed data, resulting in frequency-domain data including a plurality of coefficients, keeping only the real part or the imaginary part of each coefficient; quantizing the frequency domain data resulting in quantized data; outputting the quantized data as encoded data; and repeating the method, wherein each subsequent iteration of the step of determining a time frame includes determining a time frame that overlaps in time with a preceding time frame.

The invention discloses a self-adaptive optical spectrum imaging system, and relates to the technical field of ophthalmic optical detection. The self-adaptive optical spectral imaging system comprises a wide-spectrum illumination unit, a self-adaptive optical correction unit, a synchronous spectral imaging unit and a refraction calculation unit, illumination is carried out through a wide-spectrum light source, eye aberration is corrected in real time through self-adaptive optics, and multi-wavelength retina images are synchronously obtained through a dispersion element and an area array detector. According to the method, the refractive distribution diagram is calculated from the spectral phase gradient through Fourier phase analysis and a Levenberg-Marquardt fitting algorithm, the eye aberration is corrected in real time through adaptive optics, the diopter of each point of the retina is accurately calculated from the spectral phase gradient on the basis of the Fourier phase analysis and the Levenberg-Marquardt fitting algorithm in combination with a wide-spectrum spectral synchronous imaging technology, and the refractive distribution diagram is calculated from the spectral phase gradient through the Fourier phase analysis and the Levenberg-Marquardt fitting algorithm. And a space-time registration error caused by mismatching of sequential measurement and eyeball micro-motion in a traditional mechanical scanning mode is avoided.

This invention belongs to the field of three-dimensional dynamic topography measurement, specifically a multi-frequency structured light time-domain least squares fitting three-dimensional dynamic measurement method. It includes multi-frequency structured light projection, capturing images of stripes at different frequencies and performing Fourier analysis to extract the Fourier phase corresponding to each stripe image; obtaining the corresponding difference phase sequence centered on each frame of the multi-frequency stripe sequence; performing time-domain least squares fitting analysis on the extracted difference phase sequence to solve the wrapping phase of each frame of sampled stripes; and expanding the wrapping phase using the multi-frequency information in the sampling sequence to obtain the three-dimensional topography corresponding to each frame of sampled stripes. This invention integrates information from multiple frames of stripes at different frequencies to perform time-domain least squares fitting to solve the wrapping phase of each frame of stripes in the sampling sequence. Compared with the traditional single-frame Fourier transform method, the solution information is richer, which helps to improve measurement accuracy.

This invention discloses a phase-space collaborative method for short-term precipitation forecasting based on physical alignment, belonging to the field of meteorological early warning. This method constructs a dual-flow collaborative network that integrates spatial shape flow and Fourier phase flow to handle the local nonlinear evolution and global advection motion of the precipitation system, respectively. Cross-domain feature interaction and synchronization are achieved through a bidirectional bridging module in the collaborative converter. Finally, using the last frame of the input sequence as an anchor point, the dual-flow prediction results are fused through a last-frame calibration and mixing module to generate a high-fidelity forecast sequence. This invention effectively solves the problems of mismatch between global motion and local evolution representations, feature conflicts, and prediction ambiguity caused by energy dissipation in existing technologies, significantly improving the accuracy of short-term precipitation forecasts, especially for extreme precipitation events.

The invention discloses a design method of an optical vortex array mask plate with a controllable sub-vortex shape, and the method comprises the steps: modulating the phase of a conventional optical vortex array through combining a discrete shaping technology and a Fourier phase shift theorem; therefore, the polygonal optical vortex array with 100% space utilization rate and self-similarity characteristics is generated under the tight arrangement theory and the fractal rule. The complex transmittance function of the polygonal optical vortex array mask plate is constructed according to the method, the complex transmittance function is loaded into a spatial light modulator through a computer in an experiment, the mask plate of the polygonal optical vortex array is generated, and the mask plate can be used for generating an optical vortex array with controllable sub-vortex shapes. According to the optical vortex array with the controllable sub-vortex shape, the space utilization rate is 100% under the tight arrangement theory, the optical vortex array has self-similarity under the fractal rule, the functionality of the optical vortex array is remarkably improved, and therefore the optical vortex array has very important application prospects in the optical field.