114 results about "Reference window" patented technology

The invention discloses a segmentation combination-based adaptive constant false alarm rate target detection method for an SAR (synthetic aperture radar) image, and belongs to the technical field of synthetic aperture radars. The method comprises the following steps of: dividing a reference window into four sub windows, extracting uniformity statistics of the four sub windows and judging whether the sub windows are uniform; obtaining parameters for estimating background clutter models by adopting corresponding sub window combination strategies according to the non-uniform number, and then obtaining a detection threshold value by using a false alarm probability and a relationship between the clutter models; and comparing the pixel value of a current detection unit with the detection threshold value, judging whether a target exists, detecting the whole SAR image to be detected by adopting a running water form, and performing target fusion operation on the detected SAR image. According to the scheme, the method has low calculation quantity and simple operation, solves the problems of low detection probability, high false alarm rate and the like when the environment is complex and changeable and multiple targets are adjacent under high-resolution large scenes in the prior art, obviously improves the detection effect, and can keep good detection performance under various complex detection environments.

An improved bowstring mounted peep sight used in archery improving archer's accuracy. The present invention preferred embodiment having a body generally horizontal within bowstring axis has through the body centrally located luminous color optic cross-pieces indexing the center of the peep sight aperture. The characteristic of the present invention optic cross-pieces fiber side lit attenuation allows the archer to easily see through the large aperture peep sight aligning forward bow sight pin on color cross-pieces sectional center aperture small highlighted index reference window. Small reference index window cross hair center provides consistent centering reference within the large aperture by proximal blur designed within Fiber Optic Peep Sight. A second characteristic is both peep sight embodiment and optic cross-piece fibers be further enhanced with florescent light collecting glow pigment, dyes or other color illuminating materials for increased viewing during less than desirable lighting conditions.

The invention discloses an MMVI-CFAR target detection method. Clutter background modes which a target signal possibly undergoes are set to be a model set for overcoming the defect of detection performance at the position where different clutter backgrounds of existing radar maneuvering weak targets are connected. The method comprises the specific steps that 1, uniform clutter background models, clutter edge background models and non-uniform multi-target background models are respectively built; 2, a model set corresponding to clutter background areas is built; 3, reference windows are divided into a left reference window, a right reference window and a full reference window; 4, weight calculation is conducted according to the models, and corresponding constant false alarm processing is conducted according to the value of the weight. The MMVI-CFAR target detection method is applicable to various clutter backgrounds, and the advantages of CA-CFAR, SO-CFAR and GO-CFAR during detection of uniform clutter backgrounds, clutter edge backgrounds and multi-target backgrounds are respectively utilized; detection probability is greatly improved at the positions where different clutter backgrounds are overlapped.

A frequency monitor circuit (FMC) that is part of an integrated circuit chip for monitoring the frequency of one or more clocks present on the chip is disclosed. The FMC includes a reference window generator, operative to output a reference window signal of a given duration, and a clock counter, operative to count all pulses, in any one of the clocks, that occur within the duration of the reference window and to output a corresponding pulse count. The FMC further includes two or more comparators, each operative to compare the pulse count with a respective given threshold value and to output a corresponding indication of frequency deviation. In one configuration, in which the clock is generated on the chip by a frequency multiplier, the reference window generator and the clock counter are shared between the frequency monitor circuit and the frequency multiplier.

The invention discloses a COSGO (Average Order Statistics Greatest of)-CFAR (Constant False Alarm Rate) detection method in the work adopting a continuous wave system radar. In the COSGO-CFAR detection, firstly, n reference units in a left reference window and a right reference window of a target detection unit are sequenced from small to large according to powder; the left reference window and the right reference window respectively selects powers of former n-k units as clutter average power to respectively obtain two average clutter powders of the left reference window and the right reference window; the greater power of the two obtained average clutter powders is selected as the clutter power; and then the greater power is multiplied with a normalization threshold to obtain a real detection threshold, and the real detection threshold is compared with the power of the target detection unit to obtain a comparison result. The COSGO-CFAR detection method provided in the working adopting the continuous wave system radar realizes two-dimensional coherence accumulation through distance IFFT (Inverse Fast Fourier Transform) pulse pressure and orientation FFT (Fast Flourier Transform) pulse pressure, improves the target signal to noise ratio gain, and reduces the clutter detection omission under multi-object detection.

A method for processing a stereo image is provided which includes the steps of setting a specified area of a base window with reference to a point for obtaining a corresponding point in the base image; setting a reference window having the same size as that of the base window in the reference image; evaluating the difference between the base window and the reference window while scanning the reference window along an epipolar line; determining the position of the reference window having the minimum difference as a stereo corresponding point; measuring parallax from the difference between the position of the base window and the position of the reference window; calculating the reliability of the corresponding point (parallax) by first reliability based on the sharpness of the peak of the evaluation-value distribution of the difference of patterns between the base window and the reference window and second reliability based on the shape of the peaks; and outputting the value of the reliability of the parallax together with information on the parallax.

The invention discloses an MM-CFAR target detection method. The method is characterized by comprising the following steps that 1, uniformly-distributed clutter background models and non-uniformly-distributed clutter background models are built; 2, a model set corresponding to clutter background areas is built; 3, MM-CFAR reference windows are divided into a left reference window and a right reference window; 4, weight calculation is conducted according to the model set M, and corresponding constant false alarm processing is conducted according to the value of the weight; 5, threshold coefficients B[0] and B[1] are calculated, a detection probability formula is obtained according to the weight of CA-CFAR and CMLD-CFAR, and detection probability P[d] is obtained. The MM-CFAR target detection method is used for various clutter backgrounds, and the advantages of the CA-CFAR and CMLD-CFAR during detection in uniform backgrounds and non-uniform backgrounds are respectively utilized; compared with a general OS-CFAR, the detection probability is greatly improved in clutter edge backgrounds.

The present invention is a software method for the authoring and generation of highly resizable document layouts that automatically adapt to a wide range of window and screen sizes spanning the desktop to smartphones by interpolating and adaptively skipping the display of document layouts mapped to multiple reference windows called key-frames such that the generated document layouts and styles in a runtime document window are adjusted to be as close to the author's intent as possible. The adaptive display-skipping technique can also be extended to support adaptive pagination of document layouts.

The invention discloses a method for motion test which includes the following steps: according to the same rule, a current frame image and a reference frame image are respectively divided into at least a current window image and a reference window image; then according to the same rule, the current window image and the reference window image are divided into at least two current sub-window images and reference sub-window images; relative values of brightness of the current sub-window images, and of the reference sub-window images are obtained; then the difference between the relative value of brightness of the current sub-window images and that of the reference sub-window images is obtained and compared, and the preset threshold value is also compared; at last, the result of motion test is obtained according to the result of comparison. The invention also discloses a motion test device at the same time. The method and device of the invention are capable of avoiding the effect on motion test result which is obtained from change of brightness in the environment and increasing accuracy rate of the motion test.

The invention discloses an improved constant false alarm rate detecting method for a ship-borne linear frequency modulation continuous wave radar and belongs to the field of signal processing. The method includes: the maximum value of each Doppler channel energy after Doppler treatment of each distance unit is used as the input of a two-dimensional reference window; judgment is performed twice, targets and backgrounds are preliminarily distinguished through the first judgment, and before the second judgment, the units judged as the targets by the first judgment are removed during energy average value calculation of the distance units. Compared with traditional CA_CFAR, the method has the advantages that the defect of mutual shielding of adjacent targets is overcome, the advantage of low calculation complexity of the traditional CA_CFAR is kept, and both detection performance and software-hardware implementation cost are considered.

A video user interface display includes transformed panoramic views of a monitored area, and virtual views of portions of the monitored area. A virtual view may be based upon transformed wide-angle lens image data, or image data from a dome camera system without a wide-angle lens. The transformed panoramic views are derived from wide-angle lens image data, exhibit upright orientation and substantially reduced (or no) wide-angle image distortion, thus providing a readily discernible view of the monitored area. Reference windows overlaid in the panoramic views identify the portions of the panoramic views represented by the virtual views. The virtual views and reference windows respond to operator commands.

The invention provides a method measuring the interlayer offset of a PCB and the in-process PCB. The method comprises that reference windows whose apertures increase progressively with equal differences are formed in a metal layer at the bottom layer of the in-progress PCB; dielectric layers and metal layers are laminated on the metal layer alternatively; measurement figures and reference windows are formed in the laminated metal layer, wherein the amount of the measurement figures of the laminated metal layer equals to the sum of the amount of the reference windows and the amount of the measurement figures of an adjacent metal layer, and the centers of the measurement figures of the laminated metal layer are aligned with the centers of the reference windows and the centers of the measurement figures of the adjacent metal layer; and metal measurement holes penetrating through the dielectric layer are formed in each dielectric layer, the measurement hole is positioned between the aligned measurement figures and between the aligned measurement figure and reference window in the metal layers at two sides of the dielectric layer, the measurement hole is electrically connected with the measurement figures at two sides, and metal of the reference window in the minimal aperture is electrically connected with the measurement figure which is aligned with the reference window. The interlayer offset is determined by detecting electrical connection states between the measurement figures and the equal difference of the reference windows.

The invention discloses a method and system for detecting two-dimensional CFAR of a monopulse radar based on an FPGA. The method comprises the following steps of: A, designing a data pool, wherein thesize of the data pool is X*Y, X is a distance dimension, Y is the size of a reference window, a protection unit is set to be H, a detection factor is F, and a threshold is Z; B, judging whether a detection point is a boundary point or not, if not, executing C1, otherwise, executing C2; C1, calculating the comparison result of the energy values of the detected data in the upper direction, the lower direction, the left direction and the right direction, accumulating and multiplying F, comparing the product with Z, and if the product exceeds Z, taking the detected point as a target point; C2, dividing the upper direction, lower direction, left direction, and right direction of the detection unit into effective directions and invalid directions, wherein the number of the effective directionsis p; updating a threshold Z to p/4; calculating the comparison result of the energy value of the detected data in the effective directions, accumulating and multiplying F, comparing the product withZ, and if the product exceeds Z, taking the detected point as the target point. The method can effectively reduce false alarm; and the detection can be quickly and timely carried out when the reference window is larger.

A method for detecting and processing echo signals comprises detecting reflections of a transmitted signal as echo signals, obtaining digital magnitudes representative of an envelope of the echo signals over time, applying the digital magnitudes to a plurality of data storing cells, estimating a signal threshold by accumulating the digital magnitudes from a predetermined number of reference window cells at each side of a predetermined cell-under-test in the plurality of data storing cells and multiplying the resulting accumulated signal by a predetermined first weight factor, thus obtaining an estimated signal threshold, comparing the threshold with the signal stored in the predetermined cell-under-test in the plurality of data storing cells, thus reducing chances of false detection.

Method and apparatus for motion estimation in a video encoder is described. In one example, a motion estimator includes registers, first-in-first out (FIFO) logic, costing logic, and processing logic. The registers are configured to store an even field and an odd field of a current macroblock pair in a current frame in a video stream. The FIFO logic is configured to store a reference window of a reference frame in the video stream. The costing logic is configured to produce cost data. The processing logic is coupled to the registers, the FIFO logic, and the costing logic. The processing logic is configured to generate common sums of absolute differences (SADs) for the current macroblock pair, generate SADs for partitions of the current macroblock pair from combinations of the common SADs, and cost and minimize the SADs for the partitions.

The invention discloses a CFAR detector suitable for complex inhomogeneous clutters, belongs to the field of radar signal processing, relates to a radar self-adaptive detection technology and in particular relates to a self-adaptive constant false alarm rate (CFAR) detection method. A radar radiation region is divided into even small regions by use of a morphological classification algorithm, each small region serves as a reference window, the reference windows of the same terrain are fused, and the terrains of the various reference windows after fusion are numbered to obtain the terrain classes of the whole radar radiation region. According to the CFAR detector suitable for complex inhomogeneous clutters, cells to be detected and resolution cells in the reference window are independent identically distributed even in an inhomogeneous background, and the performance of the detector is not affected by the inhomogeneous background. As a result, the CFAR detector suitable for complex inhomogeneous clutters is capable of solving the problem of acute drop of the performance of the CFAR detector when the radar scans a complex region in practical application, and has the outstanding advantages of high accuracy and good practicability.

he invention relates to a ground penetrating radar underground horizon detection method. The method comprises steps that S1, a ground penetrating radar echo signal is inputted; S2, an initial reference track and an initial search point are determined through the echo signal, a search track is determined, a relevant threshold Tc and a distance threshold D are determined, and sizes of a reference window and a search window are determined; S3, a cross-correlation value r(m) of a signal in the reference race reference window and a signal in a next signal search track window is calculated; S4, a search track horizon, a next reference track and a next signal search track are determined according to the calculation result and the set thresholds Tc and D; and S5, horizon detection is carried out through iteration of the steps S3-S4. According to the method, on the basis of correlation and continuity among ground penetrating radar signals, rapid effective extraction of the underground horizon information of the ground penetrating radar signals is realized, and great importance to ground penetrating radar data interpretation and geological analysis in engineering applications is realized.

The present invention provides a self-adaptive culling algorithm-based target detection method. According to the technical scheme of the method, firstly, the number of reference cells in a reference window is counted, and the background noise power is estimated. Secondly, a power detection threshold is calculated. Finally, whether a target exists or not is judged though the target discrimination process. Therefore, the technical problem that an existing method is too small in detection rate, and too high in missing detection rate and false alarm rate can be solved. The above method is high in target detection rate, and low in missing detection rate and false alarm rate.

The invention relates to a radar target detection-based free slide window type constant false alarm rate (CFAR) control method. The method includes the following steps that: a unit Xi in an input signal Xt (t=1...m) sequence is selected as a detected unit, and the detected unit is adopted as a center, the left side and the right side of the detected unit are respectively provided with a protective unit B1 and a protective unit B2, and then, n units at the left side of the B1 are adopted as an initial free reference window body, and the length of the window body is fixed as L=n; the window body slides from left to right one unit by one unit until reaching n units at the right side of the protective unit B2, with the length of the window body being constant, and altogether, the number of times of slide is n, and n slide windows are obtained; comparative statistics is preformed on average values of the slide windows, so as to determine the final amplitude value of the free slide windows; the final amplitude value of the slide windows is multiplied by a nominal factor T, so that a judgment threshold value S can be obtained; and finally, the detected unit Xi is compared with the threshold value S, if Xi>S, it indicates that a target exists, otherwise, it indicates that no target exists. With the radar target detection-based free slide window type CFAR control method of the invention adopted, the constant false alarm rate of target detection can be maintained, and the detection probability of a target shielding effect and a clutter edge effect can be improved.

An embodiment of the invention provides a target detection method and device. The method includes the steps of: forming a distance Doppler two-dimensional plane; for each Doppler channel of the distance Doppler two-dimensional plane, determining a detected distance unit; determining initial reference windows of a constant false alarm left window located at the left side of the detected distance unit, and determining initial reference windows of a constant false alarm right window at the right side; determining an amplitude average value of the initial reference windows of the constant false alarm left window, determining an amplitude average value of the initial reference windows of the constant false alarm right window, selecting the larger amplitude average value as a target amplitude average value, and multiplying the target amplitude average value by a set fast multiplying factor, thereby obtaining a judgment threshold value; and if the amplitude value of the detected distance unit is larger than the judgment threshold value, determining that a target exists in the detected distance unit. The target detection method provided by the embodiment of the invention can control the false alarm probability, thereby improving target detection performance.

A method of selecting a motion vector for use in a motion estimation system in which the motion vector defines movement of a block of pixels between a search window and a reference frame. The method includes the steps of scanning a search window in a fixed order for a suitable match with an area of the reference frame such that each search position within a current row or column of the window is one pixel away from a previous search position, defining a preferred point in the search window, calculating a primary norm function with reference to the preferred point for a given position in each row or column, calculating a norm function for each search position based on a linear increment of the primary norm function for the respective row or column, calculating an Absolute Error (AE) for each search position, based on a difference between a given property of the search position and a position in the reference window, and selecting a motion vector, the displacement of the motion vector defined in terms of the search position having the smallest AE and the smallest norm function. An apparatus for performing the method is also disclosed.

A method for block-based motion estimation, the flexible triangle search (FTS) algorithm is provided. The FTS is based on the simplex algorithm for optimization adapted to an integer grid. The proposed algorithm is highly flexible because of its ability to quickly change its search direction and to move toward the target of the search criterion. Motion estimation in a search window is in relation to a reference window. The motion estimation comprises searching. Searching is comprised of the steps of expanding, translating, contracting and reflecting. A system for block-based motion estimation is also provided.