200 results about "Automatic threshold" patented technology

An implantable cardiac rhythm management device operable in an autothreshold or autocapture verification mode, wherein the rhythm management device is capable of detecting noise that affects signal characteristics of a sensed intracardial evoked response electrogram signal. The device includes a noise detection circuit that determines whether a minimum peak timing occurs during a predetermined time following delivery of a stimulation pulse. If a minimum peak timing occurs during the predetermined time following delivery of the stimulation pulse, then significant amounts of noise affecting the signal characteristics of the electrocardiogram signal is assumed.

The invention discloses a system and methods for quantitating the presence of nucleic acid sequences by evaluation of amplification data generated using real-time PCR. In one aspect, the methods may be adapted to identify a threshold and threshold cycle for one or more reactions based upon evaluation of exponential and baseline regions for each amplification reaction. The methodology used in the analysis may be readily automated such that subjective user interpretation of the data is substantially reduced or eliminated.

The invention provides a method for the outline automatic extraction of a level set medical ultrasonic image area based on an edge and a statistical characteristic, aiming at the characteristics of low contrast degree and small signal-to-noise ratio of medical ultrasonic images and designing a method for the outline extraction of the level set area based on the edge and the statistical characteristic. The method comprises three steps of: 1, carrying out area outline coarse extraction, completing image inverse extraction and self-adapting Gaussian function background suppression, applying otsu image automatic threshold algorithm to convert the image into a binary image, and carrying out image degreasing interference operation and closed area outline extraction work; 2, adopting a selectivity aeolotropy medical ultrasonic image smoothing algorithm to pre-treat an original image; and 3, carrying out the precise extraction of the level set image area based on the edge and the statistical characteristic. Experimental results indicate that compared with the prior method, the method of the invention can obtain a more precise partition result.

System and method for improving the detection performance of a wirelessly transmitted signal. A preferred embodiment comprises specifying a desired response for missed channel detection and false alarm probabilities for a plurality of signal qualities and determining if a channel detection threshold is based on missed channel detection or false alarm probabilities for the plurality of signal qualities. A signal quality estimate of a channel can be inferred from a signal quality measurement of a second channel, wherein the channel and the second channel are sourced by a single transmitter. The channel detection threshold can be adjusted based upon the previously determined required response and the signal quality estimate of the channel.

The invention relates to an intermediate frequency direct sequence spread spectrum receiver for satellite ranging, which consists of 37 parts of a front-end A / D, an FFT module, a local PN code generator, a correlator, an automatic threshold calculation module and the like. The connection relationship is as follows: the output of the front-end A / D and the output of a carrier tracking loop NCO are respectively connected to an in-phase branch multiplier and an orthogonal branch multiplier, the input of the front-end A / D and the input of the carrier tracking loop NCO enter into an in-phase branch FIR low-pass filter and an orthogonal branch FIR low-pass filter, consequently, on the one hand, the output is sent to an integral zero clearing device, then the output which is sent to the FFT module, a branch 1 local PN code memory ROM and a branch 2 local PN code memory ROM enters into a branch 1 complex multiplier and a branch 2 complex multiplier, the output is sent to a branch 1 root mean square module and a branch 2 root mean square module, the output is sent to the threshold calculation module and a capturing and judging module for carrying out code catching; and on the other hand, the output is sent to the correlator and the local PN code generator for carrying out code tracking. The output of the correlator is simultaneously sent into a frequency discriminator / phase discriminator of the carrier tracking loop and then enters into a loop filter of the carrier tracking loop, and the output of the loop filter of the carrier tracking loop enters into the carrier tracking loop NCO for carrying out carrier tracking.

The invention discloses a system and methods for quantitating the presence of nucleic acid sequences by evaluation of amplification data generated using real-time PCR. In one aspect, the methods may be adapted to identify a threshold and threshold cycle for one or more reactions based upon evaluation of exponential and baseline regions for each amplification reaction. The methodology used in the analysis may be readily automated such that subjective user interpretation of the data is substantially reduced or eliminated.

A method for automatic threshold control and detection of lead failure in an implanted medical device obtains three sensing vectors for measurement of an electrocardiogram signal. A dynamic error signal is determined from the vectors, and may be used to set a detection threshold for insufficient ECG signals, and / or to passively monitor the device for indications of lead failure without performing an impedance measurement. Passive mode operation conserves battery power and enables continuous lead integrity checks. A quality factor may also be determined from the error signal, to indicate whether or not signal measurements are valid with respect to noise levels. If the detection threshold is allowed to decay between successive features of the electrocardiogram, the decay rate may be made adaptive such that it automatically adjusts to changes in heart rate or to changes in amplitude of the electrocardiogram features.

The invention discloses a preprocessing method and a preprocessing system used for extracting breast regions in mammographic images. The method includes steps: subjecting the mammographic images to automatic threshold segmentation to obtain binary images; subjecting communicated regions in the binary images to filling processing to remove labels and holes in the mammographic images; dividing the binary images into a plurality of subregions, and binarizing each subregion according to local threshold value to position breast contour regions; subjecting the binary images and the breast contour regions to set 'and' operation, searching number of pixel points in each subregion containing difference in the binary images along a reference line from top to bottom, and positioning the subregion with maximum number of pixel points in regions containing difference to be nipple regions. By overall automatic threshold segmentation and local threshold analysis, the breast regions and the nipple regions in the mammographic images can be accurately positioned, the preprocessing process is low in computation complexity, and execution efficiency is high.

Disclosed are systems and methods for identifying and quantitating the presence of one or more DNA species in a sample population through PCR amplification. DNA species quantitation includes a determination of a threshold fluorescence value used in the assessment of the PCR amplification reaction. Various embodiments of the present invention incorporate an enhancement function useful in selecting appropriate threshold fluorescence values and facilitate the determination of DNA concentrations by quantitative PCR based methodologies.

System and method for improving the detection performance of a wirelessly transmitted signal. A preferred embodiment comprises specifying a desired response for missed channel detection and false alarm probabilities for a plurality of signal qualities and determining if a channel detection threshold is based on missed channel detection or false alarm probabilities for the plurality of signal qualities. A signal quality estimate of a channel can be inferred from a signal quality measurement of a second channel, wherein the channel and the second channel are sourced by a single transmitter. The channel detection threshold can be adjusted based upon the previously determined required response and the signal quality estimate of the channel.

The invention discloses a metal surface fine defect detection method based on vision. The metal surface fine defect detection method comprises the following steps that S1, collecting four to-be-detected metal surface images with different illumination angles through a four-point light source three-dimensional detection system; S2, calculating a light source direction corresponding to each image; S3, restoring the curvature image of the surface of the object through the gradient information; S4, performing preprocessing operation of gray scale transformation and mean filtering on the curvatureimage in sequence; S5, performing threshold segmentation on the preprocessed image by using an automatic threshold segmentation method; S6, removing misjudged pixel points and tolerable fine defects through the area characteristics, and judging whether the product has defects or not; And S7, extracting the texture features of the defects, and classifying the products with the defects through pattern recognition. The defect that in the prior art, the metal surface defect detection omission ratio is high is overcome, and the purposes of rapidly identifying defective products and efficiently classifying the products are achieved.

A method of controlling a queue buffer (2), said queue buffer (2) being connected to a link (1) and being arranged to queue data units (30) that are to be sent over said link (1) in a queue (20), comprising: determining (S1) a value (QL; QL?av#191) of a length parameter related to the length of said queue (20), comparing (S2) said value (QL; QL?av#191) with a length threshold value (L?th#191; min?th#191; max?th#191) and performing (S3) a congestion notification procedure if said value (QL; QL?av#191) is equal to or greater than said length threshold value (L?th#191; min?th#191; max?th#191), and an automatic threshold adaptation procedure (S4, S7), where said automatic threshold adaptation procedure (S4, S7) is arranged to automatically adapt said length threshold value (L?th#191; min?th#191; max?th#191) on the basis of one or more characteristics of said link (1).

A method and system for selecting a threshold for use in detecting anomalous objects, or targets, in images with a tractable false alarm rate. A method includes steps of identifying a number of peak values from a plurality of values; calculating an average peak value from the identified peak values derived in the previous step; and calculating the threshold according to the average peak value; the number of identified peak values; and a predetermined number of false alarms. In this manner, object classifications are accurate; the number of false alarms is reduced; and redundant classifications are minimized for each image.

An implantable cardiac stimulation system capable of automatic capture verification is provided with an associated method for performing automatic testing functions using programmable, or automatically determined, AV delays. Automatic threshold testing and evoked response sensitivity testing performed at a user-specified AV delay setting, rather than a preset setting, allows assessment of automatic capture verification based on an AV delay relevant to daily system function. Further features of the present invention are an adjustable frequency with which automatic threshold tests are performed and an adjustable frequency with which threshold test results are stored in memory in a threshold record for better monitoring of lead stability or impending clinical problems. The frequency of performing threshold tests and the frequency of storing threshold test results may be varied according to the threshold stability. Stored threshold test results are advantageously displayed with respect to a fixed or variable time scale.

The invention provides an automatic SAR (synthetic-aperture radar) image rectification method. In the method, the problems encountered when feature points are selected by SIFT (scale-invariant feature transform) rectifying points under the condition of SAR image complex landforms are analyzed, the feature points are combined with the Delaunay triangulation network and coded, and triangle similarity of coded feature points are judged through automatic threshold values according to the Delaunay triangularization principle. Since SIFT rectification and the Delaunay triangulation network have robustness to geometric changes such as rotation, wrong rectifying points rectified by the SIFT can be filtered by the SIFT-Delaunay encryption algorithm according to the similarity among triangles, and accurate rectification can be achieved.

A mold monitoring method based on a FAST-9 image characteristic rapid registration algorithm include the following process: when mold open of an injection molding machine is in place and after an ejector pin is ejected, standard form images are acquired respectively; operating state information of the injection molding machine is waited, when the injection molding machine is operated to the place of the mold open, images of surfaces of a mold cavity are taken continuously through a camera, current frames of the monitored images are preprocessed, and preparations are made for subsequent image rapid registration; the FAST-9 image characteristic rapid registration algorithm is carried out; after registration, differences are made between the current frames and the form images; through adoption of the ostu automatic threshold value partitioning algorithm, binaryzation of the images is achieved, and continuous closing and opening operation is conducted on the images; whether anomaly exists in molding of products is checked through electron hole detection, when the anomaly exists, alarm information is displayed; otherwise, the operating state information of the injection molding machine in the next period is waited. The mold monitoring method based on the FAST-9 image characteristic rapid registration algorithm is good in real-time performance and strong in robustness.

The invention discloses an automatic identification method and an automatic identification device for fetal movement. The method comprises the following steps of: performing data acquisition on all signals comprising fetal movement signals; filtering and pre-processing the acquired signals to separate out the fetal movement signals; performing real-time analysis on the signals according to the characteristics of the fetal movement signals to obtain corresponding real-time threshold values; and identifying the separated fetal movement signals according to the obtained threshold values to obtain frequency and duration of the fetal movement. By adopting the scheme, noise of fetal heartbeat, maternal respiration and the like can be effectively filtered, and the fetal movement information can be extracted; an automatic threshold value regulating algorithm can regulate the threshold values aiming at different pregnant women, and can regulate the threshold values along with signal intensity variation in a monitoring process so as to avoid the condition that the fetal movement cannot be detected or is detected falsely because of the fixed threshold values; and the fetal movement information can be accurately identified, and the frequency of the fetal movement and the duration of single fetal movement in the monitoring process can be calculated.

A queue buffer control system is described, in which a queue length parameter QL is compared with a length threshold value Lth for triggering a congestion notification procedure that comprises a decision procedure for deciding whether to perform congestion notification or not. Also, an automatic threshold adaptation procedure S5 for adapting the threshold Lth on the basis of an estimated link capacity value LC is provided. The automatic threshold adaptation procedure S5 is operable notification in one of at least a first and a second adaptation mode, the first adaptation mode being associated with minimizing queuing delay and adapting the threshold value Lth on the basis of n·LC, where n≧1, and the second adaptation mode being associated with maximizing utilization and adapting the threshold value Lth on the basis of m·LC, where m>1 and m>n.

The invention belongs to the field of network security situation awareness, and particularly relates to a network security situation awareness analysis method based on log and SNMP information fusion. The method includes the steps of performing data collection based on log and SNMP data fusion, performing preprocessing based on log and SNMP data fusion, performing log data analysis and SNMP data analysis, performing log and SNMP data fusion and performing visualization on log and SNMP data fusion. Compared with a method for analyzing log data or SNMP data sources singly, through combination of the two kinds of data, the overall operation trend of the network situation can be well analyzed, and analysis is more comprehensive and more accurate. According to a system, data with a high important degree is selected to be processed according to user requirements, and the burden of processing a large number of data is relieved. An automatic threshold value correction method is used, therefore, threshold value parameters defined by a user are more accurate, and the accuracy of data fusion is improved.

The invention discloses an intelligent potato sorting method and apparatus, comprising a mechanical potato sorting apparatus, a potato grading control method and a potato appearance quality detection method. A potato intelligent grading apparatus is formed by additionally installing a computer vision detection device and an intelligent grading control device on the basis of the mechanical potato sorting apparatus. The potato grading control method comprises a shooting control unit and a grading control unit. The potato appearance quality detection method comprises the following steps: image acquisition and preprocessing; shape detection; green skin detection; and defect detection. The shapes of potatoes are graded by calculating ovality by using an approximate ellipse method according to national standards of China and external characteristics of the potatoes; the phenomenon of green skin is detected by using the values of an R component and an H component according to color characteristics; defects are detected by using automatic threshold segmentation and are determined according to the area ratio of the defects. The grading apparatus and grading method provided by the invention overcome the disadvantages of subjectivity, low efficiency and the like of artificial detection, enable quantitative detection to be more objective and scientific, are applicable to quality grading and commerce circulation of produced potatoes and improve production efficiency.

In a water resource remote sensing survey, water body information is required to be extracted by using a middle-high-resolution image along with fine management of the water resource. However, since a high-resolution satellite image has fewer bands, the construction of an automatic water body extraction model is not facilitated, and further relatively fewer methods for effectively extracting water body information are available, and the error extraction rate and the extraction omission rate are higher. The invention constructs a new SPOT5 image-based automatic water body extraction method. According to the method, the polarization of the grey value of a water body is realized by constructing a calculation model capable of homogenously enhancing a water body index and multiple indexes based on remote sensing image background value research, and high-precision automatic extraction of the water body is realized on the basis by using improved automatic threshold selection algorithm, mathematical morphological filtering algorithm and thinning algorithm and the like. Experimental comparison shows that the influence of topographic shadowing, an inhabited place and the like can be eliminated to the greatest extent, a larger water body can be effectively extracted, and higher extraction precision on a finer water body is realized.

The present invention discloses an image detection method for detecting a foreign body in an airport runway. The method comprises: manually inspecting an airport runway, and after determining no foreign body, acquiring a frame of background image of the airport runway by using a sensor; acquiring a current image of the airport runway in real time by using the sensor; by means of a feature matching algorithm, performing registration on the current image and the background image; performing a differential operation on the current image and the background image, to obtain a background difference image of the current image; performing automatic threshold binarization on the background difference image of the current image, to obtain a binarized graph of the current image; performing non-linear filtration and morphological processing on the binarized graph of the current image, to facilitate detection of a target; and identifying the target by using an edge detection or convex hull detection algorithm, and if the target is detected, sending out an alarm to end a process, and if the target is not detected, updating the current image into a next frame of background image for image detection. The method provided by the present invention is capable of accurately detecting the foreign body and achieves a relatively low calculation amount.

An automatic threshold control device for a burst mode optical receiver is disclosed. The receiver includes a converter that converts a burst mode signal into a voltage signal and an automatic gain controller for automatically controlling a gain of the converter, independently generating a reset signal and applying it to the automatic threshold control device. The automatic threshold control device is adapted to detect a voltage level of an output signal from the converter. The device includes a peak detector that detects a peak level of the output signal from the converter in response to the reset signal, a bottom level detector that detects a bottom level of the output signal from the converter in response to the reset signal, a pair of resistors having their one sides connected respectively to the peak detector and bottom level detector and their other sides connected to each other, the resistors generating a reference voltage on the basis of voltages of the peak level and bottom level, and a capacitor for storing the reference voltage.

The invention discloses a text clustering method on the basis of an automatic threshold fish swarm algorithm. The text clustering method includes computing a similarity matrix of feature vectors of texts, acquiring an initial equivalent partitioning threshold of each text by a corresponding row of elements of the similarity matrix, performing initial equivalent partitioning for the texts and determining an initial clustering number and an initial clustering center; and adopting the artificial fish swarm algorithm in a combination manner, updating the state of each artificial fish according to global optimal information and local optimal information, searching a global optimal clustering center and clustering initial clustering results again. The text clustering method has the advantages that the initial clustering number and the initial clustering center are acquired by a process for automatically acquiring the thresholds, the global optimal clustering center is searched by the aid of the artificial fish swarm algorithm, accordingly, shortcomings that the traditional clustering method is sensitive to initial values and only relies on local data characteristics and the like are overcome, and the text clustering accuracy and the text clustering intelligence can be improved.

The embodiment of the invention provides a method for tongue crack recognition, wherein the method provided by the invention is used for solving the problem of automatic crack recognition in the prior tongue diagnosis, and comprises the following step: performing the automatic threshold filtration on an image on the basis of the maximum between-class variance method (OSTU) so as to remove the noise and enlarge the recognition range. The invention provides an image feature recognizing and denoising method which comprises the following steps: after obtaining a standard tongue image, converting the standard tongue image into a gray image; copying the image, dividing two images into small regions according to the size of the image, wherein any small region of two images cannot overlap with the small region of an original image; independently filtering each small region of two images by using the OTSU filter method; combining the two images in accordance with a certain rule according to the filter results of the two images; and denoising the filtered image so as to eliminate the interference.

The invention discloses an automatic threshold value image segmentation method based on an entropy value and facing to transmission line part identification, comprising the following steps: converting an input transmission line colour image into a gray level image, and establishing a gray level histogram and an entropy value histogram aiming at the gray level image; determining a proper gray level stretching scheme according to the entropy value histogram, and stretching the gray level of the gray level image; repeating method for establishing the gray level histogram and the entropy value histogram in the last step, and reestablishing the entropy value histogram of the gray level image the gray level of which is stretched; finding an inflection point of entropy value saltation on an entropy value curve when the entropy value histogram appears to be a monotone increasing curve; evaluating the inflection point by a maximum distance method, wherein a gray level value corresponding to the inflection point is the optimal threshold value of the image threshold value segmentation; and changing the threshold value of the gray level image which is stretched by the optimal threshold value so as to complete the image segmentation. The invention has easy algorithm realization, low operation cost and high operation speed and can meet the need of the real-time preprocessing of a high-resolution image of the automatic line walking of transmission line taking the sky as a main background.

The invention discloses a method for automatically cutting a granular object in a digital image, belonging to the technical field of digital image processing. The method comprises the following steps of: firstly, separating an object from a background by applying an automatic threshold method by aiming at characteristics such as gray level, structural distribution, geometry and the like of the granular object in the digital image, particularly a microscopic image; then, calculating a gradient vector field of the object, and searching a key point in the gradient vector field, wherein the idealkey point has corresponding gradient vector distribution in eight neighborhoods, the gradient value of the key point is zero, and the acquired key point is used as the center of each granular object;next, defining a new effective energy function based on the gray level and a space position so as to calculate a direction gradient to replace the traditional gray level gradient; and finally, searching the boundary of the granular object by applying an active contour model. By using the method, the aggregated granular object can be accurately and effectively cut, particularly, a great number of adhered or overlapped micro-grains exist in a biomedical microscopic image, and therefore, help is provided for the image analysis and identification.

The invention provides a machine vision-based stainless steel soup ladle defect detection method. The machine vision-based stainless steel soup ladle defect detection method comprises the following steps: S1), acquiring a to-be-detected stainless steel soup ladle surface defect image; S2), sequentially performing graying, gray scale transformation and image smoothing pretreatment on the acquired surface defect image; S3), performing threshold segmentation on the pretreated image by an automatic threshold segmentation method to obtain a plurality of independent areas; S4), eliminating misjudgedpixel points and tolerable tiny defects through area characteristics and judging whether defects exist in the products or not; and S5), classifying the products with the defects through roundness characteristics and performing pixel area calculation and positioning on the defects in the image. By the method, the defect detection of the stainless steel soup ladle can be realized, the detection accurate rate of the stainless steel soup ladle product surface scratch defects is up to 100 percent, the integrated defect detection accurate rate is up to 96 percent or more, different types of defectsof the soup ladle can be detected pertinently, the detection efficiency is high, and the detection stability is achieved.

Video segmentation methods and systems are described wherein scene images of subjects and background are captured by video and are automatically segmented according to subject content, as by system determination of the nature of subjects. Segmentation transformations of an original background and foreground images in the scenes are provided as a terrain map. Automatic segmentation threshold adaptation is based on measuring the segmentation noise while holding the number count of noise blobs constant, whereby to achieve noise-adaptive segmentation gain. Automatic threshold adaptation within multiple areas of the scene results in different possible thresholds in different areas based on the amount of segmentation noise in each area. Segmentation is improved accordingly.

The invention relates to an automatic eyeground image blood vessel segmentation method based on Gabor filters. The method comprises steps that, as a segmentation result is guaranteed to be valid, the direction of the filter is effectively reduced, automatic selection for filter parameters and a threshold is realized, a green channel image having the optimum blood vessel contrast is firstly selected before a pre-processing stage, an eyeground image blood vessel edge is roughly extracted by utilizing 20 Gabor filters having different angles, the largest response of the filters is taken as the rough positioning position of a blood vessel, during filter parameter selection, the optimized ICA algorithm is introduced to realize automatic parameter selection, during binary threshold selection, on the basis of largest accuracy principle, automatic threshold selection is realized, and an image mask acquired through morphological processing is utilized to remove a false positive area of the segmentation edge to acquire the final blood vessel segmentation result.