31 results about "Coherence factor" patented technology

A method of operating an ultrasound imaging system having an array of transducer elements. The method comprises transmitting a plurality of ultrasound signals, each transmission using a different sub-aperture of the array, receiving a plurality of reflected ultrasound signals by a receive array corresponding to each sub-aperture transmission, calculating a coherency factor corresponding to the proportion of coherent energy in the received signals from each sub-aperture transmission and weighting the received output by the calculated coherency factor, and synthesizing all weighted outputs under all different sub-aperture transmissions.

An ultrasound diagnostic device includes: an ultrasound probe which transmits ultrasound toward a tested subject by a plurality of transducers and obtains a received signal; a beam forming section for adding the received signal for each of the transducers with matching a phase of the received signal; an image processing section which generates an image data; a coherent factor calculation section which calculates a coherent factor which represents a ratio of a coherent sum to an incoherent sum; a coherent factor correction section which corrects the coherent factor so as not to be smaller than a predetermined value; and a signal correction section which correct the received signal after having been subject to the adding, by multiplying the received signal after having been subject to the adding by the coherent factor corrected by the coherent factor correction section as a coefficient.

A set of NxM signals are acquired from an object, where N is the number of array elements and M corresponds to variations in data acquisition and / or processing parameters. The parameters include transmit aperture functions, transmit waveforms, receive aperture functions, and receive filtering functions in space and / or time. A coherence factor is computed as a ratio of the energy of the coherent sum to the energy of the at-least-partially incoherent sum of channel or image signals acquired with at least one different parameter. Partial beamformed data may be used for channel coherence calculation. For image domain coherence, a component image is formed for each different transmit beam or receive aperture function, and a coherence factor image is computed using the set of component images. The coherence factor image is displayed or used to modify or blend other images formed of the same region.

The present invention relates to an encoding method processing video object planes (VOPs) of I, P or B type and including a dynamic allocation of said VOPs. According to said method, for each input frame a preliminary forward motion estimation is carried out between current and previous frames. Current and previous motion fields are then used to evaluate a coherence factor, expressed as connected to the sums of local differences within current and previous motion field. According to the value of the coherence factor with respect to an empirically determined threshold, a decision is finally taken on the type of the frame to be coded.

The embodiment of the invention provides an ultrasonic image processing method, device and equipment. The method comprises the steps of obtaining a coherence factor of each pixel point of an ultrasonic image; determining a credibility value of each pixel point according to the coherence factor; and processing the ultrasonic image according to the credibility value of each pixel point. According tothe method provided by the embodiment of the invention, the image quality of the ultrasonic image is improved.

There is provided a method for correcting a photo mask, which allows the difference between a test mask and a corrected mask with respect to an error of line width depending on coarse / dense pattern to be decreased when the photo masks are corrected by optical proximity effect correction.The present method is consisted of: producing a test mask which acts as a mask for extracting process model for applying an optical proximity effect correction method (s1); transferring and measuring the dimensions of the transferred pattern using the test mask (s2 and s3); obtaining a function model (referred to as process model) of which a simulated result of the transferred pattern of a mask pattern of the photo mask using a function model matches the measured result (s4); obtaining a mask pattern of which a transferred pattern matches a designed pattern using said process model and creating mask data in accordance with the obtained mask pattern (s5); producing a corrected mask in accordance with the created mask data (s5); and setting an exposing condition where an OPE characteristic becomes flat with respect of wide and narrow pitches by adjusting at least one of a numerical aperture (NA) and a coherence factor (σ) of an exposing device when the corrected mask is transferred.

The present invention provides a method and apparatus for detecting fire in a monitored area even if the flames are hidden behind obstructing objects. The steps of this method include: (a) detecting and capturing, at a prescribed frequency, video images of the monitored area, (b) converting the captured images into two-dimensional bitmaps of the temporally varying brightness values observed in the captured images, wherein the spatial resolution of this bitmap is determined by the number of pixels comprising the bitmaps, (c) specifying for any two of the pixels in the bitmaps a temporal coherence factor whose magnitude is a measure over a prescribed time of the similarities observed in the temporal variations of the brightness values being captured at each of the bitmap's pixels, (d) computing this temporal coherence factors for each of the prescribed set of pixels in the captured images, and (e) analyzing the computed temporal coherence factors to identify those sets of pixels that have temporal coherence factors whose values are above a prescribed threshold value, wherein this prescribed threshold value is set so as to identify those pixels that correspond to regions of the monitored area whose temporal variations in brightness indicate that the source of this brightness is a fire in the monitored area.

The invention discloses a coherent factor adjusting device in a photoetching illuminating system. The coherent factor adjusting device comprises a reflecting mirror group, a collimating mirror group and a conical prism group, wherein the reflecting mirror group is positioned on an optical path of the front end of the illuminating system, rotates at high precision under the driving of a motor and can have relatively high rotating precision; the collimating mirror group is positioned on an optimal path of the illuminating system behind the reflecting mirror group; the conical prism group is positioned on an emergent light path of the collimating mirror group; uniform light intensity distribution is obtained on a mask surface through rear uniform illuminating subsystems. According to the coherent factor adjusting device, multi-level change of coherent factors is realized by utilizing a simple method, the transmittance rate of the system is increased, and the purposes of simplifying the structure and reducing the cost are achieved.

The invention discloses a multi-baseline PolInSAR vegetation parameter inversion method considering the time decoherence factor, comprising the following steps: step 0, introducing the time decoherence factor into the RVoG model, and obtaining the RVoG extended model taking the time decoherence factor into consideration; step 1. Perform preprocessing and polarization interferometry on the multi-baseline polarization interferometric SAR image of the vegetation to obtain multi-baseline multi-polarization complex coherence coefficient observations; step 2. Set and calculate the initial value of the vegetation parameter inversion of the RVoG extended model ; Step 3, select one of the N baselines as a reference baseline, and consider that it does not have the influence of time decoherence factors; Step 4, match the observed values ​​with the RVoG extended model, and construct the observation equation; finally, according to the parameters obtained above value, using a nonlinear iterative algorithm for vegetation parameter inversion. The invention can improve the accuracy of vegetation parameter inversion and is easy to realize.

The invention discloses a CCD image sensor based method for measuring the coherence factor of a photo-etching machine illuminating system online. The main body of a measuring system is mainly composedof three parts: (A) a CCD probe module composed of a pinhole, a lens set, and CCD; (B) a scanning control module composed of XY scanning console and a driver; and (C) a data acquisition and storage processing module composed of a data acquisition card and a computer. The method has the advantages that CCD is used to replace photoresist, through pin-hole imaging, the energy distribution of light spots collected by CCD is analyzed and calculated to obtain part of measurement values of coherence factors, the reutilization rate is high; the measurement precision is high, the responding time is quick, the light sensing time is shortened, the detection efficiency is improved; the CCD is connected to the computer, real-time automatic information processing and data storage are realized, the method is suitable for online detection of a photo-etching system installation and debugging process; the illuminating system coherence factor is measured on the mask surface, problems can be found in time, and the error can be accurately positioned.

The invention discloses a coherent factor adjusting system in a deep ultraviolet lithography lighting system. The coherent factor adjusting system comprises a converging lens group, light-homogenized robs, a control device and a lighting field, wherein the converging lens group is arranged on a lighting light path of the lighting system and is responsible for converging the light to an appointed position; the light-homogenized robs are arranged on the light path of the converging lens group of the system; the light converged by the converging lens group enters through incidence ends of the light-homogenized robs and exit through exit ends of the light-homogenized robs; the control device is used for fixing a plurality of light-homogenized robs with different aperture ratios, and is provided with a rotating shaft which is parallel to the optical axis of the lighting system; the control device rotates around the rotating shaft so as to adjust the positions of the light-homogenized robs, so that appointed light-homogenized robs are put in the light path of the lighting system to join in adjusting coherent factors of the lighting system; the control device is driven by a high precision rotary table; relay lenses are arranged on the exit light path of the light-homogenized robs; and the lighting field is arranged on the exit light path of the relay lenses. By utilizing the coherent factor adjusting system, the coherent factors of a system can be adjusted, or the design complexity of a varifocus lens can be simplified, so that the purposes of simplifying the structure and reducing the cost are achieved.

The present invention discloses a high-seed super-resolution MIMO (multi input multi output) array imaging method. The method includes the following steps that: step 1, data sampling is performed on an MIMO array; step 2, an MIMO-RMA (range migration algorithm) is utilized to complete three-dimensional reflectivity image reconstruction; step 3, the acceleration of the MIMO-RMA is utilized to calculate a coherence factor; and step 4, the coherence factor corrects a reflectivity three-dimensional image. According to the imaging algorithm of the invention, reflectivity incoherent power is simplified by rearranging echo data, the acceleration of the MIMO-RMA is utilized to calculate the coherence factor, and the calculation speed of the coherence factor is greatly increased in combination with a parallel algorithm; super-resolution performance is balanced through controlling parameters alpha and beta according to a defect that the coherent factor suppresses weak scattering points, and at the same time, the stability of the algorithm is not affected; and the coherence factor is utilized to correct the reconstructed three-dimensional image, so that sidelobe and ground noises can be effectively suppressed, and higher resolution can be achieved.

The present invention discloses a wave number domain coherence factor-based high-speed super-resolution stagnation point scanning imaging method. The method specifically includes the following steps that: step 1, an antenna receives and records echo signals; step 2, a reflectance function is calculated; step 3, a coherence factor is calculated; and step 4, the coherent factor is used to correct an image. According to the algorithm of the invention, the concept of the space-domain coherence factor is expanded to the wave number domain, and a distance migration imaging algorithm is used in combination, and therefore, the method can have real-time imaging capacity; and if combined with a parallel algorithm, the method can further improve efficiency. Compared with a traditional distance migration imaging algorithm and back-projection imaging algorithm, the wave number domain coherence factor-based high-speed super-resolution stagnation point scanning imaging method has higher resolution and lower side lobe and can effectively suppress base noises. Since parameters alpha and beta are adopted to adjust the performance of the coherence factor, and the suppression of the coherence factor on side lobe and weak scattering points can be balanced, and therefore, performance is stable.

The invention discloses a method for self-adaptation ultrasonic imaging of a spatio-temporally smoothed coherence factor type. The method comprises the following steps that (1) beam forming preprocessing is conducted; (2) beam forming processing is conducted, wherein beam forming processing comprises the steps that delayed focusing is conducted on each channel received signal, a coherence factor value of the spatio-temporally smoothed coherence factor type is calculated according to the channel received signal after delayed processing, and weighted processing is conducted on the coherence sum of the received signals through coherence factors so that beams of each scanning line can be obtained and output; (3) beam forming post-processing is conducted, wherein beam forming post-processing comprises the steps that envelope detection, logarithm compression, scanning conversion and display are conducted on the scanning lines. According to the method for self-adaptation ultrasonic imaging of the spatio-temporally smoothed coherence factor type, side lobe can be restrained, sound disorder is reduced, the contrast ratio of an image is improved, an artifact is remarkably eliminated, the imaging quality is improved, the calculation complexity is low, and the method is easy to achieve in hardware.

The invention relates to an extraction method and device based on a high-precision map data recommendation sample. The method comprises the following steps: obtaining a data source of a high-precisionmap; determining the number of recommended samples, sample data records and the number of elements according to inspection standards; collecting a coherence factor according to the data source; determining recommended samples meeting conditions according to the coherent factors and the elements; and randomly extracting the recommendation samples meeting the conditions. According to the method, the problem that manual selection of sampling data is tedious is solved, the sample selection time is saved, the extraction process of the high-precision map data recommendation samples is more scientific, and the sampling process reflects the overall situation more accurately due to more sample coverage.