20 results about "Ringing artifacts" patented technology

The invention discloses a generative adversarial network image enhancement method combined with frequency domain information, relates to the technical field of computer vision, and solves the problems of spectrum leakage, ringing artifacts, splicing strips and structural dislocation easily caused by the existing frequency domain image enhancement method. The specific scheme is as follows: receiving a degraded image and extracting multi-scale features and boundary section features; the method comprises the following steps of: performing overlapping partitioning and periodic continuation expansion on the basis of features, performing spectral analysis on an expansion block to generate a parameterized window function and performing windowing, then obtaining a preliminary reconstructed image through complex field correction and overlapping perception mixed inverse transformation, and finally performing optimization reconstruction under a generative adversarial framework through a multi-scale wavelet decomposition and sub-band fusion decoder to obtain a reconstructed image. According to the method, the consistency of space geometric precision and texture details can be kept while artifacts and seams are inhibited, and the applicability and stability of image enhancement in a complex scene are improved.

A method of ultrasound imaging based on an analog signal from an ultrasound transducer system is provided. The ultrasound transducer system includes: a piezoelectric ultrasound transducer; a resonance matching network connected to the piezoelectric ultrasound transducer and configured to receive an electrical signal from the piezoelectric ultrasound transducer and provide a passive voltage gain; and a low-noise amplifier connected to the resonance matching network and configured to receive and amplify the electrical signal from the resonance matching network. The method includes: converting the analog signal received from the ultrasound transducer system to a digital signal; attenuating ringing artifact in the digital signal based on a ringing artifact attenuation machine learning model to produce a ringing artifact attenuated digital signal; constructing an ultrasound image by beamforming imaging based on the ringing artifact attenuated digital signal; and enhancing a resolution of the ultrasound image based on a resolution optimization function to produce an enhanced ultrasound image, the resolution optimization function being configured based on a point spread function (PSF) of a transducer degradation model of the piezoelectric ultrasound transducer. There is also provided a corresponding ultrasound imaging system and a corresponding ultrasound transducer and imaging system.

The present application belongs to the technical field of medical ultrasonic signal processing, and specifically relates to a spermatic vein ultrasonic imaging enhancement system and method based on double-wall filtering and adaptive Doppler signal processing. The system comprises a dynamic reconfigurable analog front end, a dual-channel heterogeneous data processing unit and a closed-loop feedback controller. The method extracts fluid dynamics characteristics in real time through an auxiliary path, intelligently identifies resting state and action mutation state. At the action mutation moment, the physical layer automatically switches the analog filtering parameters to prevent signal saturation, and the digital layer adaptively increases the FIR filter weight to eliminate the ringing artifact; in the resting state, the high-gain analog configuration is maintained and the IIR filter is dominated to capture weak signals. With the delay buffer mechanism, accurate timing alignment of control instructions and imaging data is realized. The present application effectively solves the contradiction between low flow rate detection sensitivity and strong tissue motion interference suppression, eliminates the flicker artifact generated by breath holding action, and significantly improves the diagnosis accuracy of weak reflux.

The present invention provides a method for eliminating ringing artifacts in single-pixel imaging, belonging to the field of image filtering technology. The present invention uses a Butterworth low-pass filter to automatically eliminate the ringing artifacts from a single-pixel imaging spectrum graph containing ringing artifacts and reconstruct a higher-quality image. The present invention solves the problem that ringing artifacts exist in the reconstructed target scene of SPI at low sampling rates. The present invention can automatically eliminate ringing artifacts using only a Butterworth low-pass filter, which is more efficient than existing methods and provides a method for achieving high-quality SPI at low sampling rates.

The invention discloses an adaptive method for removing ringing artifacts in single-element endoscopic ultrasonic based on time-frequency analysis filtering. Steps: obtain original data of endoscopic single-element ultrasonic imaging, perform time-frequency spectrum analysis on adjacent frame signals; determine mutation of the time-frequency spectrum of the signal to be processed relative to reference signal by using an optical flow method; determine a threshold coefficient and spectral distribution factors to set parameters of a time-frequency filter; perform time-frequency filtering on the signal to be processed, and then perform time-domain recovery; calculate index of filtered and original data, and optimize and adjust threshold parameters based on whether index meets standard; perform time-frequency filtering, time-domain reconstruction, and ultrasonic endoscopic image reconstruction. The method nearly eliminates ringing artifacts, restores effective echo signals, and maintains structural integrity during close-range imaging.

The present invention discloses an adaptive single-element endoscopic ultrasound ringing artifact removal method based on time-frequency analysis filtering. The method is as follows: Obtain the original data of endoscopic single-element ultrasound imaging, and perform time-frequency spectrum analysis on adjacent frame signals; Obtain the mutation situation of the time-frequency spectrum of the signal to be processed relative to the time-frequency spectrum of the reference signal according to the optical flow method; Determine the threshold coefficient and the spectrum distribution situation factor, and determine the parameters of the time-frequency filter through these two parameters; Perform time-frequency filtering on the signal to be processed by the initially calculated time-frequency filter and perform time-domain recovery; Calculate the indexes using the data after removing the artifacts by time-frequency filtering and the original data, and optimize and adjust the threshold parameters according to whether the indexes meet the standards; Use the time-frequency filter parameters with qualified indexes to perform time-frequency filtering, time-domain reconstruction, and ultrasound endoscopic image reconstruction on the data. This method can almost completely remove the ringing artifacts, restore the effective echo signals, and maintain the structural integrity during near-distance imaging.

The invention provides a coding method and device for weakening a ringing effect, and the method comprises the steps: S1, comparing the RDCost of a current block in two modes of division and non-division, carrying out the pre-judgment of the division modes, and selecting a division scheme with the smaller RDCost; s2, judging whether the ringing effect does not exist in the current block by utilizing a quantization module of the video encoder, if so, ending ringing effect detection, and if not, further judging whether the ringing effect exists in the current block by utilizing a pixel change condition in an image block of the video encoder; s3, further judging the ringing effect of the current block, if the original pixels of the sub-block of the current block are flat, but the reconstructed pixels of the sub-block of the current block are not flat, judging that the ringing effect occurs in the block, forcibly selecting a division mode, and ending the ringing effect detection; and if all the sub-blocks are traversed and ringing effect detection is not quitted, the division scheme is kept unchanged. The method has the advantages that operation is simple, hardware implementation is facilitated, the overall compression ratio is not affected, and subjective quality can be effectively improved.

The present application relates to the technical field of image processing, and discloses a kind of polarization filtering and light field imaging's underwater alum flower identification method and system, solve the problem that prior art cannot realize the high-fidelity acquisition and accurate quantification of alum flower morphological characteristics under high turbidity, dynamic water quality working condition.The present application is through the collaborative optical design of polarization filtering and light field imaging, suppresses water backscattering and Mie scattering interference at the collection source, provides high-fidelity image basis for subsequent morphological quantification;Introduce double-domain Gaussian window spectrum shaping and truncated sinc interpolation kernel, improve the refocusing position accuracy without hardware modification, eliminate the ringing artifact and phase distortion caused by traditional linear interpolation;Multi-scale Retinex enhancement model accurately adapts to the low contrast and multi-scale texture characteristics of alum flower, retains the texture information required for fractal dimension calculation completely under the premise of avoiding noise amplification, and linear fitting is combined with box counting method, so that the fractal dimension estimation error is reduced.

Exemplary systems, methods and computer arrangement for decorrelating and removing noise, and / or for removing Gibbs ringing data from at least one image can be provided. In one example, there can be a procedure for receiving information related to the at least one image; a procedure for producing the at least one image based on the determination if the noise is decorrelated; a procedure to remove the noise from the at least one image; a procedure for detecting an oscillation pattern from at least one edge of a measured portion of k-space associated with the information; and a procedure for removing the Gibbs ringing artifact from the information based on the detected oscillation pattern.

Provided is a self-adaptive single-array-element endoscopic ultrasonic ringing artifact removal method based on time-frequency analysis filtering. The method is as follows: acquiring endoscopic single-array-element ultrasonic imaging original data, and performing time-frequency spectrum analysis on adjacent frame signals; according to an optical flow method, obtaining a time-frequency spectrum mutation condition of a time-frequency spectrum of a signal to be processed relative to a reference signal; determining a threshold coefficient and a frequency spectrum distribution condition factor, and determining parameters of a time-frequency filter by means of the two parameters; performing time-frequency filtering on the signal to be processed by means of a time-frequency filter obtained by means of preliminary calculation and performing time domain recovery; performing index calculation on data after the artifact is filtered out by using time-frequency filtering and the original data, and optimizing and adjusting threshold parameters according to whether an index reaches a standard or not; and performing time-frequency filtering, time domain reconstruction, and ultrasonic endoscopic image reconstruction on the data by using a time-frequency filter parameter with the index reaching the standard. According to the method, the ringing artifact can be almost completely removed, an effective echo signal is recovered, and the structural integrity during short-distance imaging is maintained.

The invention relates to the technical field of image processing, discloses an underwater alumen ustum recognition method and system based on polarization filtering and light field imaging, and solves the problem that in the prior art, high-fidelity acquisition and accurate quantification of alumen ustum morphological characteristics cannot be realized under the working conditions of high turbidity and dynamic water quality. Through the collaborative optical design of polarization filtering and light field imaging, backscattering and Mie scattering interference of a water body is inhibited at an acquisition source, and a high-fidelity image basis is provided for subsequent form quantification; a double-domain Gaussian window frequency spectrum shaping and truncated sinc interpolation kernel is introduced, the precision of a refocusing position is improved under the condition that hardware does not need to be changed, and ringing artifacts and phase distortion caused by traditional linear interpolation are eliminated; the multi-scale Retinex enhancement model accurately adapts to the low-contrast and multi-scale texture characteristics of alumen ustum, texture information required by fractal dimension calculation is completely reserved on the premise of avoiding noise amplification, and the fractal dimension estimation error is reduced by combining linear fitting of a box counting method.

The present invention discloses a defocused image deblurring method based on boundary neighborhood gradient difference, which belongs to the technical field of computer vision. In view of the fact that the existing defocused image deblurring method cannot accurately obtain the blur amount of the boundary position of the defocused image for static scenes with multiple depth layers, the present invention makes full use of the relationship between the boundary neighborhood gradient difference and the blur amount to accurately obtain the blur amount of the boundary position of the defocused image, thereby solving the problem of boundary ringing artifacts appearing in the deblurring result; in view of the problem that the ability of the non-blind deconvolution algorithm to retain image detail information is not strong enough, resulting in the loss of detail information in the deblurring result, the present invention combines the discrete blur amount selection strategy and the sparse prior to design a non-blind deconvolution algorithm to enhance the ability of the non-blind deconvolution algorithm to retain image detail information, solves the problem of the loss of detail information in the deblurring result, and can be used for defocused image deblurring processing in static scenes with multiple depth layers.

A method and wireless device with a counterpart presence detector is provided. The detector includes only memory and logic circuits to detect a change in a ringing artifact from the presence of a RF device. The memory stores template signals and threshold values. The template signals may be generated using a metal object positioned various distances from the RF device. The ringing artifact, also called an RF-off signal, is sampled. A difference between subsequent ringing artifact samples is taken to produce a ringing artifact difference. Also, a difference between subsequent samples of a template signal is taken to produce a template difference. A Euclidean distance between the ringing artifact difference and the template difference is determined. The distance is compared to a threshold value. A presence of another RF device within the RF field of the RF device is detected if the distance compares favorably to the threshold value.

The invention discloses a self-adaptive ring artifact removal method, device and equipment based on mean projection and a medium, and the method comprises the steps: carrying out reconstruction operation on original mean projection according to a first spatial parameter to obtain pre-reconstructed mean projection, and detecting a non-linear region in the pre-reconstructed mean projection, performing a reconstruction operation on the nonlinear region according to the second spatial parameter to obtain a reconstruction mean projection; and carrying out artifact removal on projection data according to the original mean projection and the reconstructed mean projection. According to the method, the original mean projection is pre-reconstructed by using the first spatial parameter, and the nonlinear region in the pre-reconstructed mean projection is optimized and reconstructed by using the second spatial parameter, so that the accuracy of the nonlinear region is improved on the basis of ensuring the smoothness of the reconstructed mean projection, the removal effect of stripe artifacts is effectively ensured, and the user experience is improved. Therefore, the removal effect of the ring artifacts in the reconstructed CT image is improved.

To provide a method for reducing noise of a permeability image obtained from an X-ray transmission image (noise derived from optical system and changing with passage of time), and a method for reducing a noise-induced ring artifact from a reconstructed image.SOLUTION: Provided is a method for reducing the noise of a permeability image obtained from an X-ray transmission image. The method includes: a step 1 for obtaining a plurality of transmission images while there are no transmission images of a measurement object and there are no measurement objects; a step 2 for selecting a permeability image having a noise of transmission image closest to the noise of a transmission image of the measurement object from a plurality of transmission images while there are no measurement objects; and a step 3 for obtaining a permeability image in which noise is reduced from the transmission image of the measurement object, against the selected transmission image as a background.SELECTED DRAWING: None

The application discloses a video motion magnification method based on a Transformer network, and steps of the method comprise the following steps: 1, extracting motion representation by using a proposed motion representation encoder; 2, calculating the difference of the motion representation to obtain motion changes; 3, performing nonlinear magnification by using a proposed motion magnification conversion module to obtain magnified motion representation; 4, fusing the magnified motion representation with the features of the motion representation of a query frame; 5, obtaining fine magnified fusion features by using a proposed multi-refinement decoder; and 6, reconstructing a high-quality motion magnification image. The application can quickly and accurately magnify and visualize the micro motion in a video which is difficult for the human eye to observe, and the proposed Transformer network can effectively suppress problems such as ringing artifacts, noise and motion blur existing in the motion magnification video, so that a high-quality motion magnification video can be generated.

The application provides a CT image ring artifact suppression method, device, equipment and storage medium, an initial CT image is acquired, and a data set is made according to the initial CT image; a RAS_UNet network model is constructed, and a loss function is designed for the RAS_UNet network model; then the data set of the initial CT image is input into the RAS_UNet network model, the RAS_UNet network model can suppress the artifact in the initial CT, and a first CT image and a second CT image after artifact suppression processing are output, the removal of the ring artifact is realized, finally, effective information in the first CT image and the second CT image is fused, and a final CT image after fusion is output, details and structures of the final CT image after fusion can be effectively recovered, and the signal-to-noise ratio can be obviously improved.

An image processing apparatus according to an embodiment includes processing circuitry. The processing circuitry determines, with respect to each of the pixels included in a magnetic resonance image, a shift amount from the position of the pixel to a position where ringing artifacts will be reduced and performs a ringing correction to correct the ringing artifacts occurring in the magnetic resonance image on the basis of the determined shift amounts. The processing circuitry estimates, with respect to each of the pixels, a local amplitude of ringing artifacts, and performs the ringing correction on the magnetic resonance image while determining the shift amount of each of the pixels so as to be approximately continuous with the shift amounts of adjacently positioned pixels, sequentially in descending order starting with pixels having a higher local amplitude on the basis of the estimated local amplitudes of ringing artifacts.

The invention relates to the technical field of medical image processing, in particular to an imaging method and device of an intravascular ultrasonic image and electronic equipment. The method comprises the following steps: acquiring an original echo signal; according to the voltage threshold value of the previous frame of ultrasonic image, determining the actual time length of the residual wave influence of the current frame of ultrasonic image; according to the afterwave influence optimization duration of the previous frame of ultrasonic image and the afterwave influence actual duration of the current frame of ultrasonic image, determining the afterwave influence optimization duration of the current frame of ultrasonic image; adjusting vertical coordinate voltage values corresponding to all time points within the afterwave influence optimization duration of the current frame of ultrasonic image in the original echo signal into a voltage threshold value of the previous frame of ultrasonic image to obtain an adjusted echo signal; and imaging by adjusting the echo signal to obtain a current frame of ultrasonic image. The technical problem that in the prior art, ring artifacts appear in an intravascular ultrasonic image due to the residual vibration effect of a transducer, and the quality of the ultrasonic image is affected can be solved.

The present invention discloses a low-light video image enhancement method based on an adaptive clipping coefficient, which combines GAMMA correction with the CLAHE algorithm and selects different clipping coefficients according to different image blocks in each frame of the video, overcoming the over-enhancement and ring artifacts phenomena existing in the existing CLAHE algorithm when processing video images, effectively improving the contrast and details of each frame of the image, and achieving a good enhancement effect. Experimental results show that the present invention has an obvious enhancement effect on video images under low-light and shooting scene limitation conditions, significantly improves the quality of video images, and enhances the image details.