222results about How to "Suppress artifacts" patented technology

In order to achieve higher coding efficiency, suppress coding artifacts, and not to need a large computing amount, an image and video data are coded. Provided is an image coding method of coding image data on a block-by-block basis, and the method includes: coding a current block according to a prediction based on a selected prediction mode (S101); determining an estimated prediction mode from among candidate prediction modes; and outputting the coded current block and mode information for reconstructing the selected prediction mode (S108). The determining includes: detecting an edge (S103); reducing the candidate prediction modes in number based on the detected edge (S105); determining the estimated prediction mode from among the candidate prediction modes reduced in number (S106); and generating the mode information based on the estimated prediction mode and the selected prediction mode (S107).

Methods and systems are provided for suppressing speckle and / or diffraction artifacts in coherent structured illumination sensing systems. A coherent radiation pattern forms an interference pattern at an illumination image plane and illuminates an object. Radiation scattered or otherwise emitted by the object is detected to produce a signal, which is integrated in time. Coherent artifact suppression is attained by using a spatial modulator, such as an acousto-optic device, to vary a phase gradient at the illumination image plane during the signal integration time. Various embodiments are provided for purposes including without limitation: preserving the depth of field of the coherent illumination; using the same acousto-optic device for pattern generation and coherent artifact suppression; electronically controlling the effective spatial coherence of the illumination system; and reducing errors due to coherent artifacts in a laser-based three dimensional imaging system.

Systems and methods are provided for constructing a composite image having an extended depth of focus from a plurality of spatially congruent source images of lesser depth of focus. The systems and methods are relatively fast, preserve detail, provide robust results on a variety of unpredictable workpiece features and configurations, and tend to suppress or reduce out-of-focus artifacts. The composite image is constructed by edge and / or boundary analysis to identify well-focused edges or boundaries in the source images. Each particular edge or boundary in the composite image is determined based on the source image containing the best-focused instance of each particular edge or boundary. The composite image is constructed outside of the previously constructed portions by surface analysis to identify well-focused surfaces in the source images, Each particular surface portion in the composite image is determined based on the source image with the best-focused instance of each particular surface portion.

A magnetic resonance imaging (MRI) system includes an ECG detector for the patient object being imaged and an element for performing an MRI pulse sequence. An imaging unit defined by the pulse sequence is longer in temporal length than one heart beat represented by the EGG signal. An MR signal is acquired from the object in response to the pulse sequence and an MR image based on the acquired MR signal is produced. A plurality of divided MT pulses can be applied instead of the conventional single MT pulse. In this case, an SE-system pulse sequence having a shorter echo train spacing is used, to generate sounds by applying gradient pulses incorporated in an imaging pulse sequence so as to automatically instruct a patient to perform an intermittent breath hold during three-dimensional scanning.

The invention relates to a CT (Computed Tomography) transmission imaging beam hardening correcting method and particularly relates to a base image TV minimized model based CT beam hardening correcting method. On the basis of establishing a beam hardening correcting model with an adjustable parameter, the base image TV model based CT beam hardening correcting method comprises the following steps: firstly, converting an original projection data through the model pretreatment so as to obtain sets of pretreated projection sequences under different adjustable parameter conditions; respectively reconstructing the pretreated projection sequences, thereby obtaining a series of corrected base images; taking a full-variation function of a target image as a cost function and obtaining an optimal solution of a weighting coefficient according to an iterative method; and lastly, summing the weights of the obtained series of base images, thereby forming a final reconstructed image. Compared with the traditional method, the method provided by the invention has the advantages that the priori knowledge, such as scanning copy material, radiation source condition, and the like, is unnecessary, the method is unlimited by external conditions and is strong in universality, and the linear combination is solved when a weighting coefficient is confirmed, so that the method has the advantages of small computation complexity and short operation time.

A method for suppressing measurement system signature, or artifacts, that arise when controlled source electromagnetic survey data are inverted to obtain a resistivity image of a subsurface region. The method involves identifying regions (47) where the image has low or rapidly varying sensitivity to data acquired by a given receiver, typically regions close to and under the given receiver. Then, in the iterative inversion process where a resistivity model is updated to minimize an objective function, the model update is modified (48) to reduce the impact of such low sensitivity regions on the update.

A hierarchical motion deblurring method for a single image is provided. In the method, a blur kernel of a target image is calculated and a multi-scale representation for representing the target image and the blur kernel is constructed. Then, a gradient attenuation function and a strong edge suppression function are applied to a residual Richardson-Lucy algorithm, so as to iteratively calculate a residual image between the blur kernel and the target image represented by the representation in each scale and restore the residual image to obtain a first restored image and a second restored image. Finally, the two restored images are compared so as to obtain a motion deblurring image.

MRI echo data is acquired by performing selective-excitation on regions composed of multi-slices of an object, while the object is moved continuously. The positions of the multi-slices are moved within a predetermined imaging range fixedly determined by an MRI system, according to object movement. This allows positions of the multi-slices to be changed in compliance with the moved object, so that the multi-slices positionally track with the object within the imaging range. Accordingly, a multi-slice imaging technique can be provided, which is executable during even continuous movement of the object.

A magnetic resonance imaging (MRI) system includes an ECG detector for the patient object being imaged and an element for performing an MRI pulse sequence. An imaging unit defined by the pulse sequence is longer in temporal length than one heart beat represented by the ECG signal. An MR signal is acquired from the object in response to the pulse sequence and an MR image based on the acquired MR signal is produced. A plurality of divided MT pulses can be applied instead of the conventional single MT pulse. In this case, an SE-system pulse sequence having a shorter echo train spacing is used, to generate sounds by applying gradient pulses incorporated in an imaging pulse sequence so as to automatically instruct a patient to perform an intermittent breath hold during three-dimensional scanning.

A device (100) for processing data, the device (100) comprising a plurality of signal paths (130, 140, 150) each receiving an identical analog input signal (104), at least one signal conditioning unit (101 to 103) in at least one of the plurality of signal paths (130, 140, 150), wherein each signal conditioning unit (101 to 103) is adapted for generating a respective analog intermediate signal (105 to 107) by manipulating a property, particularly an amplitude, of the analog input signal (104), and a plurality of analog to digital converting units (108 to 110) each of which being assigned to a corresponding one of the plurality of signal paths (130, 140, 150) and being supplied with the analog input signal (104) or a respective analog intermediate signal (105 to 107), wherein each of the plurality of analog to digital converting units (108 to 110) is adapted for generating a respective digital intermediate signal (111 to 113) based on the respective analog intermediate signal (105 to 107) or based on the analog input signal (104); a digital signal processing unit (114) supplied with the plurality of digital intermediate signals (111 to 113) and adapted for generating a digital output signal (115) by processing the digital intermediate signals (111 to 113).

In order to obtain a highly reliable image with no image distortion or no artifacts, such as ghosting, by compensating for the distortion of an output gradient magnetic field waveform caused by various factors with high accuracy, an input gradient magnetic field waveform and an output gradient magnetic field waveform corresponding to the input gradient magnetic field waveform are calculated, a response function that is a sum of response functions of a plurality of elements affecting the output gradient magnetic field waveform is calculated using the input gradient magnetic field waveform and the output gradient magnetic field waveform, an output gradient magnetic field waveform is calculated from an input gradient magnetic field waveform of a gradient magnetic field pulse set in the imaging sequence using the response function, and various kinds of correction are performed using the calculated value of the calculated output gradient magnetic field waveform.

The invention discloses an X-ray multi-energy spectrum computed tomography (CT) projection data processing and image reconstruction method, which mainly comprises an X-ray energy spectrum CT projection sinogram processing method and a compressed sensing-based accelerated iterative convergent reconstruction algorithm. The X-ray energy spectrum CT projection sinogram processing method mainly comprises the following steps of: (1) restraining vertical streaking artifacts in a projection sinogram; (2) removing high-brightness noisy points in the projection sinogram. The compressed sensing-based accelerated iterative convergent reconstruction algorithm refers to that image total variation (TV) minimization-based optimal constraint conditions and the ordered-subset simultaneous algebraic reconstruction techniques (OS-SART) are combined. As a number of defects still exist in a traditional X-ray energy spectrum CT detection system (X-ray energy resolution photon counting detector), more noise and artifacts exist in acquired projection data. According to the X-ray multi-energy spectrum CT projection data processing and image reconstruction method, X-ray multi-energy spectrum CT projection data are effectively preprocessed by utilizing a preprocessing means, and meanwhile, a TV-based OS-SART algorithm is introduced into X-ray multi-energy spectrum CT image reconstruction, and therefore, image iterative convergence is accelerated, and the noise and the artifacts in a reconstructed image is well restrained.

A biomedical sensor for detecting EMG signals may include a non-conducting fixed framework supporting a symmetrical arrangement of four electrode surfaces, configured as two signal detection contacts, each with a respective associated signal reference contact. The mechanical and electrical configuration act together to suppress movement artifact.

The invention discloses a low-dose PET three-dimensional reconstruction method based on deep learning. The method comprises the following steps: carrying out lossless back projection on low-dose PET original data to an image domain; an appropriate three-dimensional deep neural network structure is selected to fit mapping between low-dose PET back projection and standard-dose PET images; after training sample learning and network parameter fixing, PET image three-dimensional reconstruction starting from low-dose PET original data is realized, so that a low-dose PET reconstructed image which islower in noise and higher in resolution compared with a traditional reconstruction algorithm and image domain noise reduction processing is obtained.

The invention discloses a forward-looking radar imaging sea-surface target key point detection and recognition method. The method includes the steps that radar echo data are quantized into a gray scale image; a region of interest is extracted from the gray scale image, partition is performed, and a target region partition image is obtained; the radar echo data and the region of interest of the image are used, and a target region peak point information matrix is obtained; information merging is conducted on the target region partition image and the target region peak point information matrix, the number K of peak points in a target region in a merging result is obtained through counting, the previous K peak points are selected and serve as target effective peak points and form a target effective peak point image in a binaryzation mode, target axial features are extracted, and a target position is determined; the center of gravity of target energy is calculated and serves as the target key point. According to forward-looking radar target features, multiple mode identification methods are used comprehensively, the inherent features of a target can be reserved, meanwhile interference factors such as artifacts and side lobes can be restrained, and the recognition accuracy and the positioning precision of radar imaging sea surface target key points are improved.

A histogram is generated on the basis of the pixel value of an image. An LUT used for changing the dynamic range of the image is generated on the basis of the histogram value in each pixel value interval of the generated histogram. The dynamic range of the image is changed on the basis of the generated LUT.

The invention discloses a three-dimensional electrical capacitance tomography (ECT) imaging image reconstruction method which employs the measuring capacitance value obtained by a three-dimensional ECT imaging sensor as the projection data for image reconstruction. In an iteration reconstruction process, a threshold filtering mode is employed to perform artifact inhibition on an obtained reconstruction image; a filtering threshold regularly performs adaptive adjustment, and is selected to minimize the fuzzy measurement of a current image. The method effectively reduces reconstruction image artifacts, improves complexly distributed three-dimensional imaging effects, and realizes real three-dimensional ECT imaging image reconstruction.

Disclosed is x-ray cone beam scan data reconstruction of an imaged object with a reconstruction algorithm using shift invariant filtering and backprojection with the maximum tomographic capability of a circular scan larger than p plus cone angle, when CB data is not truncated and data extrapolation is not allowed. The reconstruction scheme includes a conventional FDK reconstruction and a parallel reconstruction using differential back projection and 1D Hilbert transform to suppress the CB artifacts.

In the present invention, there is provided a display panel driving method of the type wherein the total light emitting period length within a one-field period is controlled to variably control the peak luminance level of a display panel, the driving method including a step of variably controlling, where the one-field period has N light emitting periods disposed therein, N being equal to or greater than 2, the light emitting period length of a particular one of the light emitting periods and the other light emitting period or periods to provide a difference in luminance between the particular light emitting period and the other light emitting period or periods so that the particular light emitting period is visually observed as the center of light emission.

A charge / discharge control circuit for controlling current through an input / output audio device includes a first voltage reference; a second voltage reference and a waveform generation circuit responsive to the first and second voltage references for generating a multi-stage waveform profile which is approximately an inaudible waveform for suppressing audible artifacts in the input / output device.

To interpolate a frame between a first frame and a second frame in a video signal, a motion-compensated interpolated frame is generated and then corrected responsive to detection of a motion vector boundary. Positions at which an absolute value of a first or second derivative of the motion vectors is not less than a predetermined amount are found to be at a motion vector boundary, and the pixel values of the pixels in an area where boundary pixels are concentrated are corrected. Blocks with at least a predetermined proportion of boundary pixels are found to be in an area where boundary pixels are concentrated.

A three-dimensional halftone screen is provided that is suited for multilevel printing. The three-dimensional halftone screen includes a plurality of planes each corresponding to one or more input intensity levels of an input RIPped pixel. Within the planes are screen dots, each associated with one or more output exposure intensity values representing an intensity of an exposure dot corresponding to the input RIPped pixel.

This invention relates to method and apparatus for subpixel-based down-sampling. This invention implements an adaptive filter 140 based on edge detection, which removes visible color fringing artifacts while efficiently retaining sharpness.