37results about How to "Avoid interpolation" patented technology

An information writing/reading apparatus is disclosed that cooperates with an information record medium including a ROM area and a RAM area, either the RAM area or the ROM area having in advance control information recorded thereon used to limit reading and/or writing of information, the information writing/reading apparatus comprising an optical pick-up unit for reading information stored on the information record medium; and a control unit for, based on the control information read by the optical pick-up unit, limiting reading and/or writing of information from/to the other area on which the control information is not recorded and outputting a signal which notifies of presence of the other area only out of the ROM area and the RAM area on the information record medium.

In a signature creating apparatus, a clock generates a time stamp and in which time can be set only by a computer installed in a certificate authority center. Further, connecting sections connects an apparatus ID for specifying an apparatus and the time stamp and personal identification information for identifying an implementor to a plain-text so as to create data for the signature. A signature creating circuit encrypts the data for the signature using a signature creating key or the like and generates the signature. A connecting section connects the signature to the data for the signature and transmits the data as data after signature.

The present invention relates to a method for post-processing a 3D digital video signal, said digital video signal having a plurality of views with associated disparity maps. The invention is characterized in that said method comprises a first step of generating a projected disparity map from an original disparity map, and a second step of filling holes within said projected disparity map, the first step comprising the sub-step of removing isolated projected pixels on said projected disparity map by filtering them.

The invention relates to a compressive sensing imaging method for a synthetic aperture radar. The method includes: constructing a standard orthogonal basis for indicating radar echo signals by the aid of a Chirp Scaling operator, processing distance-vector and azimuth-vector two-dimensional data simultaneously by compressive sensing, and sparsely optimizing finally so as to obtain high-resolution radar images based on low data size. By the method, the data size is decreased in the distance vector and the azimuth vector firstly, then the standard orthogonal basis for indicating the radar echo signals is constructed by the aid of the Chirp Scaling operator, and two-dimensional sparse optimization is performed in the distance vector and the azimuth vector by means of compressive sensing so that the radar images are obtained. The data size can be decreased effectively under the circumstance of sparse observation scenes to lower requirements on data storage devices and transmission devices of the synthetic aperture radar, and the compressive sensing imaging method is of great practical significance to a practical system.

A synthetic aperture radar polar format algorithm based on scaling principle comprises the following steps of : constructing a data collection geometric model of spotlight synthetic aperture radar; carrying out range-dimension processing pulse by pulse, inputting time-domain echo signals, subjecting the time-domain echo signals to range scaling to obtain output signals, i.e. range frequency domain signals achieving range re-sampling; processing the range frequency domain signals (scaling and focusing) to obtain an azimuth-focused image while achieving azimuth scaling (azimuth re-sampling); and subjecting the azimuth-focused data to fast Fourier transform in range dimension to obtain a two-dimensional focused image. The invention can achieve re-sampling by using two-dimensional transformation to substitute for two-dimensional interpolation in conventional PFA algorithm. The method only needs FFT and complex multiplication operation, and the computation efficiency can be improved significantly. Meanwhile, the possible phase error resulting from the finite interpolation kernel length can be obviated.

The invention relates to a feature point matching method based on correlation measurement, which comprises: shooting multiple scene images to be matched and inputting the scene images into a computer; calculating gradient of each pixel of the images, and extracting feature point information of the images; for each extracted feature point, dividing a round neighborhood into blocks by taking the feature point as a center, and calculating a gradient mean of each subarea obtained by the dividing step; utilizing the gradient of each pixel point of the subarea and the gradient mean of the subarea to establish a Harris correlation matrix of the subarea and calculate a determinant and a track of the Harris correlation matrix; utilizing the determinant and the track of the Harris correlation matrix to construct a Harris correlation measurement, and utilizing the Harris correlation measurement to construct a Harris correlation descriptor; and calculating Euclidean distance among the descriptors of the feature points, and applying measurement criteria to carry out matching. The method does not need to calibrate parameters of the pickup camera, does not need human participation during matching, automatically finishes matching, and has the characteristics of simplicity, practicality, dense matching points, high matching precision, good robustness and the like.

The invention discloses a detection method for a double cross-hole pinch Lamb wave tomographic reconstruction system. The detection method is characterized in that a projection data acquiring module (1) is connected with a projection data rearrangement module (2), the projection data rearrangement module is connected with a back projection module (3), the back projection module is connected with a filter module (4), and the filter module is connected with an image display module (5), wherein an energy transducer arranged according to a double cross-hole pinch structure of the projection data acquiring module (1) can perform projection scanning on defective areas to acquire projection data of Lamb wave; the projection data rearrangement module (2) rearranges projection data acquired by the double cross-hole pinch structure into parallel projection data; the differential and back projection module (3) performs back projection calculation on the parallel projection data in a space variation differential and an angle variation integration mode; and the filter module (4) performs finite Hilbert calculation on the back projection data to acquire reconstruction images of an object, and the reconstruction images are displayed through the image display module (5).

The invention discloses a shear mapping deformable body drawing method based on anisotropic body data, belonging to the technical field of image processing and comprising the following steps of constructing a three-dimensional data field, shear mapping, deforming and decomposing, resampling, synthesizing an intermediate image, deforming to obtain the final image, and the like. The invention is mainly improved on the steps of coordinate transformation, resampling, opacity correction and the like of an original shear mapping and deforming algorithm, can realize isotropy without cross-section interpolation operation after image data are constructed into a logic three-dimensional data field, and can directly implement body drawing operation based on an anisotropic data field, thereby not only reducing the preprocessing time, but also improving the data precision of images for drawing. In addition, a variable resampling mode is adopted in the implementation process, the sampling rate is reduced and the drawing speed is improved during mouse interaction, the sampling rate is increased and the image quality is improved when a final image is drawn, and meanwhile, the requirements for drawing speed and image precision are met.

The invention provides a lens radial distortion correction method, and belongs to the technical field of image processing. The invention can correct the obvious radial distortion of a short focal length lens, is simple in correction method, is good in correction effect, and has strong robustness. In the present invention, the J-Linkage algorithm is used to perform automatic clustering by using theJachard distance, the number of model instances does not need to be given in advance, and parameter debugging can be avoided; in the invention, according to the number of similar arcs and different distortion models, three methods are proposed to calculate the distortion center and a distortion coefficient. In the invention, the inverse model correction algorithm can avoid holes of the correctedimage, and successfully avoids additional operations such as interpolation; and a better correction effect and better real-time performance can be obtained.

The invention discloses a fisheye image distortion correction method based on a reverse polynomial model. The fisheye image distortion correction method adopts a mathematic means that reverse Taylor series fitting is carried out on a polynomial function expression built by a forward model, and a corrected image coordinate which takes a pixel as a unit is converted into an image coordinate which is not corrected and takes a pixel as the unit. Since each corrected image coordinate inevitably corresponds to a certain pixel value in the image which is not corrected through a reverse correction model, a phenomenon that individual pixels of the image are lost after correction can be successfully avoided by reverse correction so as to avoid additional operation, such as interpolation and the like, and meanwhile, a good correction effect and better real-time performance can be obtained. Under a condition that correction precision is almost unchanged, the phenomenon that the pixels of the corrected image are lost is avoided, the real-time performance of the whole correction process is improved, and for an embedded system and a site application occasion, the reverse polynomial model is superior to a traditional forward polynomial correction model.

The invention discloses an overlapped grid disturbance domain updating method for aircraft multi-body separation simulation. The method comprises the steps that a wall distance algorithm is simplified by employing an implicit assembly method based on the attribute characteristics of a wall distance marking unit, so that the grid assembly efficiency is improved; secondly, under the framework of a disturbance domain updating method, numerical simulation of the overlapped grids is realized, so that only units in a non-convergent disturbed region are subjected to interpolation operation, and the calculation amount of the interpolation operation of the overlapped grids is reduced; and thirdly, a novel overlapping grid information exchange method is established, and the mode that information is transmitted based on grid deformation and encryption in a large flow gradient area and information is transmitted based on flow gradient interpolation in a small flow gradient area is achieved, so that the accuracy of the overlapping area is improved, and the isolated point problem is avoided. According to the method, the calculation efficiency of numerical simulation of the multi-body separation problem of the aircraft can be remarkably improved, and the problems that the numerical precision is lost in a large-flow gradient grid overlapping region, and isolated points exist are solved.

The embodiment of the invention discloses a data processing method and apparatus for a foundation synthetic aperture radar, an electronic device, and a computer readable medium. The foundation synthetic aperture radar is constructed by causing a foundation radar to perform rectilinear motion along a rail. A plurality of virtual array element positions are arranged on the rail. A specific implementation manner of the method comprises the following steps: in response to determination of location at the virtual array element position at present, transmitting a frequency modulated continuous wavesignal to a monitored point target through a transmitting antenna; obtaining echo data of the monitored point target by using a receiving antenna; and in response to determining a terminal located onthe rail at present, processing the obtained echo data based on an imaging algorithm of a pseudo-polar coordinate system to generate a focusing image of the monitored point target. According to the embodiment, by adoption of the imaging algorithm of the pseudo-polar coordinate system, an interpolation process can be avoided, thereby being conducing to improving the processing efficiency of the data and realizing real-time imaging.

The invention discloses a simple and quick geometric-constraint and weight-function calculation method suitable for use in a complex aerodynamic shape of an aircraft. An entirely new evaluation methodof complex-aerodynamic-shape optimization design geometric-constraint and a method of weight-function selection of sensitivity-based multi-point optimization are adopted, geometric constraints of thickness, volume and the like of the any complex shape are accurately and conveniently calculated, and the calculation method is compatible with discrete surface multi-block-butt-joint-connection-grids,discrete surface unstructured-grids and the like; and weight-function selection can fully utilize valid information of existing weight-function data, and has weight coefficient selection instructiveness, and thus design potential of sensitivity-based optimization technology is fully exploited.

A lenticular print and method of producing that substantially reduces progressive pixel misalignment to produce a lenticular print that has increased angular resolution. The lenticular print includes a dot matrix pixel arrangement that is rotated with respect to the X-Y axis of a printer. The printed output of the rotated dot matrix pixel arrangement requires substantially no re-sampling interpolation. The lenticular print includes a conventional lenticular sheet having a plurality of convex shaped lenticular elements wherein the axis of the lenticular elements are substantially aligned with the axis of the pixel direction.

The invention provides a time-varying sea surface airborne SAR imaging simulation method based on a CSA algorithm. According to the method, the mirror scattering coefficient and the Bragg scattering coefficient are subjected to normalized superposition by using a dual-scale theoretical model, so that the whole process is simulated more finely. Echo collection is carried out on the dynamic sea surface based on the SAR imaging principle, dynamic collection is carried out on the simulated sea surface based on the created virtual buoy, and original echo data are processed into an SAR simulated image spectrum containing speed bunching modulation, tilt modulation and fluid mechanics modulation through the CSA algorithm. The imaging simulation method provided by the invention is improved on the basis of traditional sea surface SAR imaging simulation, the problem that a main image and an auxiliary image cannot be generated at the same time in the simulation process is solved, conflicts with actual measurement work are reduced to a certain extent, errors caused in the simulation process are reduced, and in the future error simulation work, multi-baseline mode simulation has reference significance to a certain extent.

The invention discloses an InSAR rapid image registration method based on quadtree segmentation. The method is characterized in that through the combination of an image quadtree segmentation criterionand an FFT maximum correlation coefficient registration principle, rough registration and rough segmentation are carried out on the InSAR main and auxiliary complex images, and then the quadtree treestructure image block segmentation and sub-block FFT maximum correlation coefficient sub-pixel registration are carried out, the sub-block quadtree segmentation and the sub-block sub-pixel registration are carried out on the InSAR complex image one by one, and the global image interpolation of the traditional FFT maximum correlation coefficient registration is avoided, and the rapid sub-pixel registration of the large-scene InSAR complex image is achieved. The global image interpolation of the traditional FFT maximum correlation coefficient registration is avoided, the operation efficiency ofthe large-scene InSAR complex image registration is effectively reduced, and the good registration precision and operation efficiency in the InSAR main and auxiliary complex images with large pixel offset change can be achieved.

The invention provides an image processing method in a electronic colposcope. Firstly, an image to be processed is segmented into three parts by using an image segmentation method, and for a key observation area, an interpolation method with high precision is adopted, and for a non-key observation area, a bilinear interpolation method with high calculation speed is adopted for interpolation; the first part is interpolated by adopting a first interpolation method, the second part is interpolated by adopting a second interpolation method, and the third part is interpolated by adopting a bilinear interpolation method. The inserted pixels of the first boundary region and the second boundary region in the intermediate image obtained after interpolation are corrected because the interpolation is easy to cause a sawtooth phenomenon in the boundary region. According to the method provided by the invention, the image processing speed of the electronic colposcope is improved, and high-quality images can be obtained.

The invention discloses an SAR imaging method and system based on synthetic bandwidth frequency scaling, which relates to the field of microwave imaging detection. Through a baseband frequency domain synthesis technology, a plurality of narrowband linear frequency modulation signals are transmitted into a repetition frequency area, narrowband target echo signals returned by the repetition frequency area are synthesized into broadband echo signals according to a baseband complex signal sequence, and the broadband echo signals are obtained on the basis that the cost of an inherent microwave transmitting end hardware structure is not increased; on the premise that a motion compensation algorithm is not adopted, the problems of distance bending space-variant and distance orientation coupling under a large squint angle are solved through a frequency scaling wave number domain imaging processing algorithm, and the complexity and response delay of the system are reduced. According to the method, bending correction is carried out by adopting FFT operation and phase function complex multiplication on distance bending space-variant correction through a frequency scaling technology, interpolation operation of an RD algorithm and a PFA algorithm is avoided, the operand is saved, and the method can be applied to some application scenes with high real-time performance requirements.