Log in

Relevant bibliographies by topics / Ringing artifacts / Journal articles

To see the other types of publications on this topic, follow the link: Ringing artifacts.

Journal articles on the topic 'Ringing artifacts'

Author: Grafiati

Published: 4 June 2021

Last updated: 11 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Ringing artifacts.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Asano, Wataru, Tomoaki Takeuchi, and Masaaki Ikehara. "Filter banks for less ringing artifacts." Electronics and Communications in Japan (Part III: Fundamental Electronic Science) 85, no. 6 (2002): 1–10. http://dx.doi.org/10.1002/ecjc.1096.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Zuo, Boxin. "Deconvolution image ringing artifacts removal via anisotropic diffusion." Optical Engineering 51, no. 5 (2012): 057001. http://dx.doi.org/10.1117/1.oe.51.5.057001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

SUMATHI, M., MURALI C. KRISHNA, and R. MURUGESAN. "GA-BASED OPTIMIZATION OF TAPERING WINDOWS FOR ARTIFACT REDUCTION IN FOURIER ELECTRON MAGNETIC RESONANCE IMAGES." International Journal of Computational Intelligence and Applications 08, no. 02 (2009): 111–25. http://dx.doi.org/10.1142/s1469026809002503.

Full text

Abstract:

Optimization of tapering windows for artifact reduction in two-dimensional (2D) Fourier electron magnetic resonance (EMR) tomography using genetic algorithm (GA) is presented. EMR imaging (EMRI) is a fast emerging functional imaging modality for studying free radicals in biological systems. EMRI by single point imaging (SPI) modality is a Fourier imaging technique. The bioclearance of the imaging agent as well as the need to minimize the radio frequency power deposition on the live animals, dictate reduced k-space sampling. This leads to ringing (Gibbs) artifacts in both directions of the 2D image, because, unlike the conventional MRI, SPI is phase encoding in both directions. To dampen the high-frequency components, data tapering windows are multiplicatively applied to provide tolerable blurred resultant image with reduced Gibbs ringing. To find a compromise between blur and ringing artifact, in this paper a method of optimizing the window functions by using GA is proposed. Our experiments suggest GA-based Kaiser window shows better performance by visual as well as quantitative evaluation.

APA, Harvard, Vancouver, ISO, and other styles

4

Tsai, Hsin-Che, and Jiunn-Lin Wu. "An Improved Adaptive Deconvolution Algorithm for Single Image Deblurring." Mathematical Problems in Engineering 2014 (2014): 1–11. http://dx.doi.org/10.1155/2014/658915.

Full text

Abstract:

One of the most common defects in digital photography is motion blur caused by camera shake. Shift-invariant motion blur can be modeled as a convolution of the true latent image and a point spread function (PSF) with additive noise. The goal of image deconvolution is to reconstruct a latent image from a degraded image. However, ringing is inevitable artifacts arising in the deconvolution stage. To suppress undesirable artifacts, regularization based methods have been proposed using natural image priors to overcome the ill-posedness of deconvolution problem. When the estimated PSF is erroneous to some extent or the PSF size is large, conventional regularization to reduce ringing would lead to loss of image details. This paper focuses on the nonblind deconvolution by adaptive regularization which preserves image details, while suppressing ringing artifacts. The way is to control the regularization weight adaptively according to the image local characteristics. We adopt elaborated reference maps that indicate the edge strength so that textured and smooth regions can be distinguished. Then we impose an appropriate constraint on the optimization process. The experiments’ results on both synthesized and real images show that our method can restore latent image with much fewer ringing and favors the sharp edges.

APA, Harvard, Vancouver, ISO, and other styles

5

Mason, Jeremy K., and Oliver K. Johnson. "Convergence of the hyperspherical harmonic expansion for crystallographic texture." Journal of Applied Crystallography 46, no. 6 (2013): 1722–28. http://dx.doi.org/10.1107/s0021889813022814.

Full text

Abstract:

Advances in instrumentation allow a material texture to be measured as a collection of spatially resolved crystallite orientations rather than as a collection of pole figures. However, the hyperspherical harmonic expansion of a collection of spatially resolved crystallite orientations is subject to significant truncation error, resulting in ringing artifacts (spurious oscillations around sharp transitions) and false peaks in the orientation distribution function. This article finds that the ringing artifacts and the accompanying regions of negative probability density may be mitigated or removed entirely by modifying the coefficients of the hyperspherical harmonic expansion by a simple multiplicative factor. An addition theorem for the hyperspherical harmonics is derived as an intermediate result.

APA, Harvard, Vancouver, ISO, and other styles

6

Lin, I.-Mei, and Erik Peper. "Keep Cell Phones and PDAs Away From EMG Sensors and the Human Body to Prevent Electromagnetic Interference Artifacts and Cancer." Biofeedback 37, no. 3 (2009): 114–16. http://dx.doi.org/10.5298/1081-5937-37.3.114.

Full text

Abstract:

Abstract Cell phones produce electromagnetic interference (EMI), which can cause artifacts in physiological recordings and be misinterpreted by the clinician. This study investigated the possible effect of EMI (electrical artifact) on physiological recordings when cell phones are activated/ringing. The procedure consisted of placing the cell phone at varying distances from surface electromyographic sensors. Depending on the orientation of the cell phone's antenna, the EMI produced an artifact in the physiological signal for up to 175 cm (6 ft) that can be misinterpreted by the therapist. To avoid EMI artifacts, clients and therapists should turn off their cell phones when recording physiological signals. This means turning the cell phone off and not just switching it to vibrate. In addition, recent epidemiological studies suggest that long-term intensive cell phone use may increase the risk of gliomas, auditory tumors, and salivary tumors on the side of the head to which the person places the cell phone. Thus, to reduce artifacts and biological harm, the authors recommend keeping the cell phone away from the body and the biofeedback equipment.

APA, Harvard, Vancouver, ISO, and other styles

7

Chung, Hsiao-Wen. "Alternatek-space sampling in EPI: Possible sources of ringing artifacts." Magnetic Resonance in Medicine 38, no. 1 (1997): 173–74. http://dx.doi.org/10.1002/mrm.1910380125.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Liu, Hantao, Nick Klomp, and Ingrid Heynderickx. "A No-Reference Metric for Perceived Ringing Artifacts in Images." IEEE Transactions on Circuits and Systems for Video Technology 20, no. 4 (2010): 529–39. http://dx.doi.org/10.1109/tcsvt.2009.2035848.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Cao, Zhipeng, Zhenzhong Wei, and Guangjun Zhang. "A No-Reference Sharpness Metric Based on Structured Ringing for JPEG2000 Images." Advances in Optical Technologies 2014 (June 24, 2014): 1–13. http://dx.doi.org/10.1155/2014/295615.

Full text

Abstract:

This work presents a no-reference image sharpness metric based on human blur perception for JPEG2000 compressed image. The metric mainly uses a ringing measure. And a blurring measure is used for compensation when the blur is so severe that ringing artifacts are concealed. We used the anisotropic diffusion for the preliminary ringing map and refined it by considering the property of ringing structure. The ringing detection of the proposed metric does not depend on edge detection, which is suitable for high degraded images. The characteristics of the ringing and blurring measures are analyzed and validated theoretically and experimentally. The performance of the proposed metric is tested and compared with that of some existing JPEG2000 sharpness metrics on three widely used databases. The experimental results show that the proposed metric is accurate and reliable in predicting the sharpness of JPEG2000 images.

APA, Harvard, Vancouver, ISO, and other styles

10

Yang, Xin, Yan Zhang, Dake Zhou, and Ruigang Yang. "An improved iterative back projection algorithm based on ringing artifacts suppression." Neurocomputing 162 (August 2015): 171–79. http://dx.doi.org/10.1016/j.neucom.2015.03.055.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Chen, Chun, Jun Wang, Dan Xiao, and Qiong-Hua Wang. "Fast method for ringing artifacts reduction in random phase-free kinoforms." Applied Optics 58, no. 5 (2018): A13. http://dx.doi.org/10.1364/ao.58.000a13.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Farias, Mylne C. Q., John M. Foley, and Sanjit K. Mitra. "Detectability and Annoyance of Synthetic Blocky, Blurry, Noisy, and Ringing Artifacts." IEEE Transactions on Signal Processing 55, no. 6 (2007): 2954–64. http://dx.doi.org/10.1109/tsp.2007.893963.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Zhou, Xiaohong, Zhi-Pei Liang, Gary P. Cofer, Chris F. Beaulieu, Steve A. Suddarth, and G. Allan Johnson. "Reduction of ringing and blurring artifacts in fast spin-echo imaging." Journal of Magnetic Resonance Imaging 3, no. 5 (1993): 803–7. http://dx.doi.org/10.1002/jmri.1880030518.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

HADHOUD, MOHIY M., NABIL A. ISMAIL, FAWZY A. TORKEY, and MOSTAFA A. AHMAD. "REDUCING THE WAVELET RINGING ARTIFACTS IN A LOW-COMPLEXITY VIDEO CODEC." International Journal of Information Acquisition 03, no. 02 (2006): 161–69. http://dx.doi.org/10.1142/s0219878906000927.

Full text

Abstract:

A low-complexity wavelet-based video coding technique is proposed which adopts JPEG-2000 image coding. The wavelet transformation and subband quantization are developed and optimized in order to reduce the ringing artifacts especially at very low bit rate. The proposed coding technique reduces the coding complexity and performs well at average PSNR. As compared to other rival coding methods the proposed coding policy has a good compression ratio and an improved visual quality.

APA, Harvard, Vancouver, ISO, and other styles

15

Vanmali, Ashish V., Tushar Kataria, Samrudha G. Kelkar, and Vikram M. Gadre. "Ringing artifacts in wavelet based image fusion: Analysis, measurement and remedies." Information Fusion 56 (April 2020): 39–69. http://dx.doi.org/10.1016/j.inffus.2019.10.003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Perrone, Daniele, Jan Aelterman, Aleksandra Pižurica, Ben Jeurissen, Wilfried Philips, and Alexander Leemans. "The effect of Gibbs ringing artifacts on measures derived from diffusion MRI." NeuroImage 120 (October 2015): 441–55. http://dx.doi.org/10.1016/j.neuroimage.2015.06.068.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Robitaille, Pierre-Marie. "Response to “alternatek-space sampling in EPI: Possible sources of ringing artifacts”." Magnetic Resonance in Medicine 38, no. 1 (1997): 174–75. http://dx.doi.org/10.1002/mrm.1910380126.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Carcione, José M. "Staggered mesh for the anisotropic and viscoelastic wave equation." GEOPHYSICS 64, no. 6 (1999): 1863–66. http://dx.doi.org/10.1190/1.1444692.

Full text

Abstract:

Computation of the spatial derivatives with nonlocal differential operators, such as the Fourier pseudospectral method, may cause strong numerical artifacts in the form of noncausal ringing. This situation happens when regular grids are used. The problem is attacked by using a staggered pseudospectral technique, with a different scheme for each rheological relation. The nature and causes of acausal ringing in regular grid methods and the reasons why staggered‐grid methods eliminate this problem are explained in papers by Fornberg (1990) and Özdenvar and McMechan (1996). Thus, the objective here is not to propose a new method but to develop the algorithm for the viscoelastic and transversely isotropic (VTI) wave equation, for which the technique can be implemented without interpolation. The algorithm is illustrated for one physical situation that requires very high accuracy, such as a fluid‐solid interface, where very large contrasts in material properties occur. The staggered‐grid solution is noise free in the dynamic range where regular grids generate artifacts that may have amplitudes similar to those of physical arrivals.

APA, Harvard, Vancouver, ISO, and other styles

19

Farias, Mylène C. Q., and Sanjit K. Mitra. "Perceptual contributions of blocky, blurry, noisy, and ringing synthetic artifacts to overall annoyance." Journal of Electronic Imaging 21, no. 4 (2012): 043013. http://dx.doi.org/10.1117/1.jei.21.4.043013.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Popovici, Irina, and Wm Douglas Withers. "Locating Edges and Removing Ringing Artifacts in JPEG Images by Frequency-Domain Analysis." IEEE Transactions on Image Processing 16, no. 5 (2007): 1470–74. http://dx.doi.org/10.1109/tip.2007.891782.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Gandam, Anudeep, Jagroop Singh Sidhu, Sahil Verma, et al. "An efficient post-processing adaptive filtering technique to rectifying the flickering effects." PLOS ONE 16, no. 5 (2021): e0250959. http://dx.doi.org/10.1371/journal.pone.0250959.

Full text

Abstract:

Compression at a very low bit rate(≤0.5bpp) causes degradation in video frames with standard decoding algorithms like H.261, H.262, H.264, and MPEG-1 and MPEG-4, which itself produces lots of artifacts. This paper focuses on an efficient pre-and post-processing technique (PP-AFT) to address and rectify the problems of quantization error, ringing, blocking artifact, and flickering effect, which significantly degrade the visual quality of video frames. The PP-AFT method differentiates the blocked images or frames using activity function into different regions and developed adaptive filters as per the classified region. The designed process also introduces an adaptive flicker extraction and removal method and a 2-D filter to remove ringing effects in edge regions. The PP-AFT technique is implemented on various videos, and results are compared with different existing techniques using performance metrics like PSNR-B, MSSIM, and GBIM. Simulation results show significant improvement in the subjective quality of different video frames. The proposed method outperforms state-of-the-art de-blocking methods in terms of PSNR-B with average value lying between (0.7–1.9db) while (35.83–47.7%) reduced average GBIM keeping MSSIM values very close to the original sequence statistically 0.978.

APA, Harvard, Vancouver, ISO, and other styles

22

Malvar, H. S. "Biorthogonal and nonuniform lapped transforms for transform coding with reduced blocking and ringing artifacts." IEEE Transactions on Signal Processing 46, no. 4 (1998): 1043–53. http://dx.doi.org/10.1109/78.668555.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Zhao, Hongtian, Hua Yang, Hang Su, and Shibao Zheng. "Natural Image Deblurring Based on Ringing Artifacts Removal via Knowledge-Driven Gradient Distribution Priors." IEEE Access 8 (2020): 129975–91. http://dx.doi.org/10.1109/access.2020.3007972.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Yang, Xin, Tianshu Liu, and Dake Zhou. "An adaptive super-resolution method based on regional pixel information and ringing artifacts suppression." Optik 125, no. 20 (2014): 5962–68. http://dx.doi.org/10.1016/j.ijleo.2014.07.039.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

TANIMOTO, Akihiro, Nobuya HIGUCHI, and Akihisa UENO. "Reduction of Ringing Artifacts in the Arterial Phase of Gadoxetic Acid-enhanced Dynamic MR Imaging." Magnetic Resonance in Medical Sciences 11, no. 2 (2012): 91–97. http://dx.doi.org/10.2463/mrms.11.91.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Kim, Byung-Hyun, Jun-Young Jang, Won-Woo Jang, Hyun-Chul Choi, and Bong-Soon Kang. "Improvement of Reduction method for Ringing Artifacts in color moving-pictures using K-means algorithm." Journal of the Korean Institute of Information and Communication Engineering 15, no. 3 (2011): 576–82. http://dx.doi.org/10.6109/jkiice.2011.15.3.576.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Nagahama, Yuki, Tomoyoshi Shimobaba, Takashi Kakue, Yasuhiro Takaki, and Tomoyoshi Ito. "Image quality improvement of random phase-free holograms by addressing the cause of ringing artifacts." Applied Optics 58, no. 9 (2019): 2146. http://dx.doi.org/10.1364/ao.58.002146.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Kim, Changick. "Adaptive post-filtering for reducing blocking and ringing artifacts in low bit-rate video coding." Signal Processing: Image Communication 17, no. 7 (2002): 525–35. http://dx.doi.org/10.1016/s0923-5965(02)00026-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Sandhu, Amanpreet Kaur. "An Efficient Lossless Compression algorithm for Medical images." Turkish Journal of Computer and Mathematics Education (TURCOMAT) 12, no. 3 (2021): 3793–99. http://dx.doi.org/10.17762/turcomat.v12i3.1663.

Full text

Abstract:

Medical image compression plays a vital role in diagnosis of diseases which allowing manipulation, efficient, transmission and storage of color, binary and grayscale image. Before transmission and storage, a medical image may be required to be compressed. The objective of the study is to develop an efficient and effective technique for digital medical images which alleviates the blocking artifacts from grayscale image while retaining all relevant structures. In this paper, we demonstrate a highly engineered postprocessing filtering approach has been designed to remove blocking effects from medical images at low bit rate. The proposed technique is comprised of three strategies i.e. 1) a threshold valve scheme which is used to capture the pixel vectors containing blocking artifacts. 2) Blocking artifacts measurement techniques. The blocking artifacts are measured by three frequency related modes (low, Moderate and high frequency model). 3) A directional filter which is used to remove over-smoothing and ringing artifacts near edges of block boundary. The algorithm is tested on digital medical grayscale images from different modalities. The experimental results illustrate that the proposed technique is more efficient on the basis of PSNR-B, MSSIM, and MOS indices than the state-of-the-art methods. The proposed algorithm can be seamlessly applied in area of medical image compression which high transmission efficiency and acceptable image quality can be guaranteed.

APA, Harvard, Vancouver, ISO, and other styles

30

Mann, Charles K., and Thomas J. Vickers. "S/N Enhancement of Raman Spectra Using an Interactive Filter." Applied Spectroscopy 47, no. 11 (1993): 1943–48. http://dx.doi.org/10.1366/0003702934065876.

Full text

Abstract:

The use of an interactive filter for smoothing Raman spectra is described. It is applied by fitting a polynomial to a limited range of data in a spectrum using the least-squares criterion. It provides a variable bandpass with very sharp cutoff without generating ringing artifacts. Its use is demonstrated in tailoring of the filter bandpass to the requirements of individual spectral features, in detection of weak peaks in a noisy spectrum, and in detection of minor component signals when these are superimposed on major component signals.

APA, Harvard, Vancouver, ISO, and other styles

31

Lee, Yooho, Sang-hyo Park, Eunjun Rhee, Byung-Gyu Kim, and Dongsan Jun. "Reduction of Compression Artifacts Using a Densely Cascading Image Restoration Network." Applied Sciences 11, no. 17 (2021): 7803. http://dx.doi.org/10.3390/app11177803.

Full text

Abstract:

Since high quality realistic media are widely used in various computer vision applications, image compression is one of the essential technologies to enable real-time applications. Image compression generally causes undesired compression artifacts, such as blocking artifacts and ringing effects. In this study, we propose a densely cascading image restoration network (DCRN), which consists of an input layer, a densely cascading feature extractor, a channel attention block, and an output layer. The densely cascading feature extractor has three densely cascading (DC) blocks, and each DC block contains two convolutional layers, five dense layers, and a bottleneck layer. To optimize the proposed network architectures, we investigated the trade-off between quality enhancement and network complexity. Experimental results revealed that the proposed DCRN can achieve a better peak signal-to-noise ratio and structural similarity index measure for compressed joint photographic experts group (JPEG) images compared to the previous methods.

APA, Harvard, Vancouver, ISO, and other styles

32

Block, Kai Tobias, Martin Uecker, and Jens Frahm. "Suppression of MRI Truncation Artifacts Using Total Variation Constrained Data Extrapolation." International Journal of Biomedical Imaging 2008 (2008): 1–8. http://dx.doi.org/10.1155/2008/184123.

Full text

Abstract:

The finite sampling ofk-space in MRI causes spurious image artifacts, known as Gibbs ringing, which result from signal truncation at the border ofk-space. The effect is especially visible for acquisitions at low resolution and commonly reduced by filtering at the expense of image blurring. The present work demonstrates that the simple assumption of a piecewise-constant object can be exploited to extrapolate the data ink-space beyond the measured part. The method allows for a significant reduction of truncation artifacts without compromising resolution. The assumption translates into a total variation minimization problem, which can be solved with a nonlinear optimization algorithm. In the presence of substantial noise, a modified approach offers edge-preserving denoising by allowing for slight deviations from the measured data in addition to supplementing data. The effectiveness of these methods is demonstrated with simulations as well as experimental data for a phantom and human brain in vivo.

APA, Harvard, Vancouver, ISO, and other styles

33

Nandhagopal, N., S. Navaneethan, and C. Arul Murugan. "The reordered deblocking filter and SAO architecture for HEVC system." International Journal of Engineering & Technology 7, no. 2.8 (2018): 617. http://dx.doi.org/10.14419/ijet.v7i2.8.10544.

Full text

Abstract:

High Efficiency Video Coding (HEVC) used in broad band and wireless applications employs two in-loop filters to remove the blurring artifacts, blocking artifacts and ringing artifacts. The standard h.264/AVC deblocking filter which requires more memory initially filters the horizontal borders, followed by the vertical borders. The results of vertical borders filtering are utilized in the horizontal filtering process and the obtained results are further stored in temporary memory. The proposed system comprises of a reordering filter to reduce the order of the filter and a SAO to modify the decoded samples to a new offset value inorder to perform robust encryption mechanism. Hence reorder filter reduces the memory needed for this filtering process. In HEVC, SAO is an in-loop filter and located next to deblocking filter. The idea of SAO is to compensate renovated samples by adding an offset to each pixel, so that the distortion between renovated picture and original one can be reduced. Implementation of proposed simulation work is done by Verilog HDL and implemented using Virtex 6 FPGA to compute the power and hardware requirements in terms of LUT and slice registers.

APA, Harvard, Vancouver, ISO, and other styles

34

De, Kanjar, and Masilamani V. "NO-REFERENCE IMAGE QUALITY MEASURE FOR IMAGES WITH MULTIPLE DISTORTIONS USING RANDOM FORESTS FOR MULTI METHOD FUSION." Image Analysis & Stereology 37, no. 2 (2018): 105. http://dx.doi.org/10.5566/ias.1534.

Full text

Abstract:

Over the years image quality assessment is one of the active area of research in image processing. Distortion in images can be caused by various sources like noise, blur, transmission channel errors, compression artifacts etc. Image distortions can occur during the image acquisition process (blur/noise), image compression (ringing and blocking artifacts) or during the transmission process. A single image can be distorted by multiple sources and assessing quality of such images is an extremely challenging task. The human visual system can easily identify image quality in such cases, but for a computer algorithm performing the task of quality assessment is a very difficult. In this paper, we propose a new no-reference image quality assessment for images corrupted by more than one type of distortions. The proposed technique is compared with the best-known framework for image quality assessment for multiply distorted images and standard state of the art Full reference and No-reference image quality assessment techniques available.

APA, Harvard, Vancouver, ISO, and other styles

35

Song, Jiayu, and Qing Huo Liu. "Improving Non-Cartesian MRI Reconstruction through Discontinuity Subtraction." International Journal of Biomedical Imaging 2006 (2006): 1–9. http://dx.doi.org/10.1155/ijbi/2006/87092.

Full text

Abstract:

Non-Cartesian sampling is widely used for fast magnetic resonance imaging (MRI). Accurate and fast image reconstruction from non-Cartesiank-space data becomes a challenge and gains a lot of attention. Images provided by conventional direct reconstruction methods usually bear ringing, streaking, and other leakage artifacts caused by discontinuous structures. In this paper, we tackle these problems by analyzing the principal point spread function (PSF) of non-Cartesian reconstruction and propose a leakage reduction reconstruction scheme based on discontinuity subtraction. Data fidelity ink-space is enforced during each iteration. Multidimensional nonuniform fast Fourier transform (NUFFT) algorithms are utilized to simulate thek-space samples as well as to reconstruct images. The proposed method is compared to the direct reconstruction method on computer-simulated phantoms and physical scans. Non-Cartesian sampling trajectories including 2D spiral, 2D and 3D radial trajectories are studied. The proposed method is found useful on reducing artifacts due to high image discontinuities. It also improves the quality of images reconstructed from undersampled data.

APA, Harvard, Vancouver, ISO, and other styles

36

Zhou, Xiaolin, and Yuanting Zhang. "A hybrid approach to the simultaneous eliminating of power-line interference and associated ringing artifacts in electrocardiograms." BioMedical Engineering OnLine 12, no. 1 (2013): 42. http://dx.doi.org/10.1186/1475-925x-12-42.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Zhang, Long, Steven Staelens, Roel Van Holen, Jeroen Verhaeghe, and Stefaan Vandenberghe. "Characterization of the ringing artifacts in rotator-based reconstruction with Monte Carlo-based resolution compensation for PET." Medical Physics 37, no. 9 (2010): 4648–60. http://dx.doi.org/10.1118/1.3478275.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

N., Radha, and T. Ranga Babu. "Performance Evaluation of Quarter Shift Dual Tree Complex Wavelet Transform Based Multifocus Image Fusion Using Fusion rules." International Journal of Electrical and Computer Engineering (IJECE) 9, no. 4 (2019): 2377. http://dx.doi.org/10.11591/ijece.v9i4.pp2377-2385.

Full text

Abstract:

<p>In this paper, multifocus image fusion using quarter shift dual tree complex wavelet transform is proposed. Multifocus image fusion is a technique that combines the partially focused regions of multiple images of the same scene into a fully focused fused image. Directional selectivity and shift invariance properties are essential to produce a high quality fused image. However conventional wavelet based fusion algorithms introduce the ringing artifacts into fused image due to lack of shift invariance and poor directionality. The quarter shift dual tree complex wavelet transform has proven to be an effective multi-resolution transform for image fusion with its directional and shift invariant properties. Experimentation with this transform led to the conclusion that the proposed method not only produce sharp details (focused regions) in fused image due to its good directionality but also removes artifacts with its shift invariance in order to get high quality fused image. Proposed method performance is compared with traditional fusion methods in terms of objective measures. </p>

APA, Harvard, Vancouver, ISO, and other styles

39

Yang, X., L. G. Hector, and J. Wang. "A Combined Theoretical/Experimental Approach for Reducing Ringing Artifacts in Low Dynamic Testing with Servo-hydraulic Load Frames." Experimental Mechanics 54, no. 5 (2014): 775–89. http://dx.doi.org/10.1007/s11340-014-9850-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Landi, Germana, Elena Loli Piccolomini, and Fabiana Zama. "A Total Variation-Based Reconstruction Method for Dynamic MRI." Computational and Mathematical Methods in Medicine 9, no. 1 (2008): 69–80. http://dx.doi.org/10.1080/17486700701839039.

Full text

Abstract:

In recent years, total variation (TV) regularization has become a popular and powerful tool for image restoration and enhancement. In this work, we apply TV minimization to improve the quality of dynamic magnetic resonance images. Dynamic magnetic resonance imaging is an increasingly popular clinical technique used to monitor spatio-temporal changes in tissue structure. Fast data acquisition is necessary in order to capture the dynamic process. Most commonly, the requirement of high temporal resolution is fulfilled by sacrificing spatial resolution. Therefore, the numerical methods have to address the issue of images reconstruction from limited Fourier data. One of the most successful techniques for dynamic imaging applications is the reduced-encoded imaging by generalized-series reconstruction method of Liang and Lauterbur. However, even if this method utilizesa prioridata for optimal image reconstruction, the produced dynamic images are degraded by truncation artifacts, most notably Gibbs ringing, due to the spatial low resolution of the data. We use a TV regularization strategy in order to reduce these truncation artifacts in the dynamic images. The resulting TV minimization problem is solved by the fixed point iteration method of Vogel and Oman. The results of test problems with simulated and real data are presented to illustrate the effectiveness of the proposed approach in reducing the truncation artifacts of the reconstructed images.

APA, Harvard, Vancouver, ISO, and other styles

41

JIANG, LINGLING, XIANGCHU FENG, and HAIQING YIN. "STRUCTURE AND TEXTURE IMAGE INPAINTING USING SPARSE REPRESENTATIONS AND AN ITERATIVE CURVELET THRESHOLDING APPROACH." International Journal of Wavelets, Multiresolution and Information Processing 06, no. 05 (2008): 691–705. http://dx.doi.org/10.1142/s0219691308002598.

Full text

Abstract:

Representing the image to be inpainted in an appropriate sparse dictionary, we introduce a novel method for the filling-in of structure and texture in regions of missing image information. In the morphological component analysis (MCA) inpainting approach, a TV penalty is added to better reduce ringing artifacts. However, the incorporation of TV penalty terms leads to PDE schemes that are numerically intensive. Inspired by the works of Daubechies–Teschke and Borup–Nielsen, we replace the TV term by a [Formula: see text] term. It results in an iterative curvelet thresholding scheme for the structure image inpainting. In the whole inpainting process, an alternative approach is presented to layer inpainting. Experimental results show the performance of the algorithm.

APA, Harvard, Vancouver, ISO, and other styles

42

Aharchaou, Mehdi, and Erik Neumann. "An integrated broadband preprocessing method for towed-streamer seismic data." GEOPHYSICS 85, no. 2 (2020): V201—V221. http://dx.doi.org/10.1190/geo2019-0521.1.

Full text

Abstract:

Broadband preprocessing has become widely used for marine towed-streamer seismic data. In the standard workflow, far-field source designature, receiver and source-side deghosting, and redatuming to mean sea level are applied in sequence, with amplitude compensation for background [Formula: see text] delayed until the imaging or postmigration stages. Thus, each step is likely to generate its own artifacts, quality checking can be time-consuming, and broadband data are only obtained late in this chained workflow. We have developed a unified method for broadband preprocessing — called integrated broadband preprocessing (IBP) — which enables the joint application of all the above listed steps early in the processing sequence. The amplitude, phase, and amplitude-variation-with-offset fidelity of IBP are demonstrated on pressure data from the shallow, deep, and slanted streamers. The integration allows greater sparsity to emerge in the representation of seismic data, conferring clear benefits over the sequential application. Moreover, time sparsity, full dimensionality, and early amplitude [Formula: see text] compensation all have an impact on broadband data quality, in terms of reduced ringing artifacts, improved wavelet integrity at large crossline angles, and fewer residual high-frequency multiples.

APA, Harvard, Vancouver, ISO, and other styles

43

Fang, Yu-Wen, Xiao-Mei Huo, and You-Wei Wen. "An Algorithm for the Proximity Operator in Hybrid TV-Wavelet Regularization, with Application to MR Image Reconstruction." East Asian Journal on Applied Mathematics 4, no. 1 (2014): 21–34. http://dx.doi.org/10.4208/eajam.150413.260913a.

Full text

Abstract:

AbstractTotal variation (TV) and waveletL1norms have often been used as regularization terms in image restoration and reconstruction problems. However, TV regularization can introduce staircase effects and wavelet regularization some ringing artifacts, but hybrid TV and wavelet regularization can reduce or remove these drawbacks in the reconstructed images. We need to compute the proximal operator of hybrid regularizations, which is generally a sub-problem in the optimization procedure. Both TV and waveletL1regularisers are nonlinear and non-smooth, causing numerical difficulty. We propose a dual iterative approach to solve the minimization problem for hybrid regularizations and also prove the convergence of our proposed method, which we then apply to the problem of MR image reconstruction from highly random under-sampled k-space data. Numerical results show the efficiency and effectiveness of this proposed method.

APA, Harvard, Vancouver, ISO, and other styles

44

SHIH, FRANK Y., and YAN-YU FU. "APPROXIMATE IMAGE QUALITY MEASURE IN LOW-DIMENSIONAL DOMAIN BASED ON RANDOM PROJECTION." International Journal of Pattern Recognition and Artificial Intelligence 22, no. 02 (2008): 335–45. http://dx.doi.org/10.1142/s0218001408006235.

Full text

Abstract:

Image Quality Measure (IQM) is used to automatically measure the degree of image artifacts such as blocking, ringing and blurring effects. It is calculated traditionally in the image spatial domain. In this paper, we present a new method of transforming an image into a low-dimensional domain based on random projection, so we can efficiently obtain the compatible IQM. From the transformed domain, we can calculate the Peak Signal-to-Noise Ratio (PSNR) and apply fuzzy logic to generate a Low-Dimensional Quality Index (LDQI). Experimental results show that the LDQI can approximate the IQM in the image spatial domain. We observe that the LDQI is suited for measuring the compression blur due to its relatively low distortion. The relative error is about 0.15 as the compression blur increases.

APA, Harvard, Vancouver, ISO, and other styles

45

Kazemeini, Sayed Hesammoddin, Can Yang, Christopher Juhlin, Sergey Fomel, and Calin Cosma. "Enhancing seismic data resolution using the prestack blueing technique: An example from the Ketzin C O2 injection site, Germany." GEOPHYSICS 75, no. 6 (2010): V101—V110. http://dx.doi.org/10.1190/1.3483900.

Full text

Abstract:

Restricted resolution imposes limits on the detection of subsurface geologic features using surface seismic data. Despite great improvements in acquisition and processing techniques in recent years, seismic data still suffer from limited resolution. Detailed subsurface information on the geologic conditions at depth cannot always be attained from conventional surface seismic data. For the area of this study, the carbon dioxide [Formula: see text] storage site at Ketzin, Germany, high seismic resolution is required for mapping the internal structure of the main target reservoir. Processing of the 3D surface seismic data using conventional methods did not provide optimum resolution. The spectral blueing technique attempts to enhance the surface seismic data resolution. Well-log data generally show a blue spectrum with higher-amplitudes at the higher frequencies than the commonly assumed white reflection series. By designing and applying one or several operators to poststack data, it has been possible to better match the reflectivity series and improve resolution. Applying the blueing operator to prestack data was investigated to possibly improve seismic resolution, produce more consistent results, and cause fewer ringing artifacts than when applied to poststack data. Prestack blueing, poststack blueing, and no blueing of the Ketzin 3D seismic data were compared with zero-offset vertical seismic profile (VSP) and synthetic seismograms. The comparison shows that prestack spectral blueing can indeed enhance seismic resolution with fewer artifacts associated with it than the poststack technique. The prestack and poststack spectral blueing approaches improve the well to seismic tie.

APA, Harvard, Vancouver, ISO, and other styles

46

Tsukamoto, Naoko, Yoshihiro Sugaya, and Shinichiro Omachi. "Pansharpening by Complementing Compressed Sensing with Spectral Correction." Applied Sciences 10, no. 17 (2020): 5789. http://dx.doi.org/10.3390/app10175789.

Full text

Abstract:

Pansharpening (PS) is a process used to generate high-resolution multispectral (MS) images from high-spatial-resolution panchromatic (PAN) and high-spectral-resolution multispectral images. In this paper, we propose a method for pansharpening by focusing on a compressed sensing (CS) technique. The spectral reproducibility of the CS technique is high due to its image reproducibility, but the reproduced image is blurry. Although methods of complementing this incomplete reproduction have been proposed, it is known that the existing method may cause ringing artifacts. On the other hand, component substitution is another technique used for pansharpening. It is expected that the spatial resolution of the images generated by this technique will be as high as that of the high-resolution PAN image, because the technique uses the corrected intensity calculated from the PAN image. Based on these facts, the proposed method fuses the intensity obtained by the component substitution method and the intensity obtained by the CS technique to move the spatial resolution of the reproduced image close to that of the PAN image while reducing the spectral distortion. Experimental results showed that the proposed method can reduce spectral distortion and maintain spatial resolution better than the existing methods.

APA, Harvard, Vancouver, ISO, and other styles

47

Wang, Jin, Zhensen Wu, and Young-Sup Lee. "Superresolution of Hyperspectral Image Using Advanced Nonlocal Means Filter and Iterative Back Projection." Journal of Sensors 2015 (2015): 1–5. http://dx.doi.org/10.1155/2015/943561.

Full text

Abstract:

We introduce an efficient superresolution algorithm based on advanced nonlocal means (NLM) filter and iterative back projection for hyperspectral image. The nonlocal means method achieves the to-be-interpolated pixel by the weighted average of all pixels within an image, and the unrelated neighborhoods are automatically eliminated by the trivial weights. However, spatial location distance is also an important issue to reconstruct the missing pixel. Therefore, we proposed an advanced NLM (ANLM) filter considering both neighborhood similarity and patch distance. In the conventional NLM method, the search region was the whole image, while the proposed ANLM utilizes the limited search to reduce the complexity. The iterative back projection (IBP) is a very famous method to deal with the image restoration. In the superresolution issue, IBP is able to recover the high-resolution image iteratively from the given low-resolution image which is blurred due to the noise by minimizing the reconstruction error, while, because the reconstruction error of IBP is back projection and isotropic, the conventional IBP suffers from jaggy and ringing artifacts. Introducing the ANLM method to improve the visual quality is necessary.

APA, Harvard, Vancouver, ISO, and other styles

48

Xie, Shundao, and Hong-Zhou Tan. "Blur-readable two-dimensional barcode based on blur-invariant shape and geometric features." International Journal of Advanced Robotic Systems 18, no. 2 (2021): 172988142199958. http://dx.doi.org/10.1177/1729881421999589.

Full text

Abstract:

In recent years, the application of two-dimensional (2D) barcode is more and more extensive and has been used as landmarks for robots to detect and peruse the information. However, it is hard to obtain a sharp 2D barcode image because of the moving robot, and the common solution is to deblur the blurry image before decoding the barcode. Image deblurring is an ill-posed problem, where ringing artifacts are commonly presented in the deblurred image, which causes the increase of decoding time and the limited improvement of decoding accuracy. In this article, a novel approach is proposed using blur-invariant shape and geometric features to make a blur-readable (BR) 2D barcode, which can be directly decoded even when seriously blurred. The finder patterns of BR code consist of two concentric rings and five disjoint disks, whose centroids form two triangles. The outer edges of the concentric rings can be regarded as blur-invariant shapes, which enable BR code to be quickly located even in a blurred image. The inner angles of the triangle are of blur-invariant geometric features, which can be used to store the format information of BR code. When suffering from severe defocus blur, the BR code can not only reduce the decoding time by skipping the deblurring process but also improve the decoding accuracy. With the defocus blur described by circular disk point-spread function, simulation results verify the performance of blur-invariant shape and the performance of BR code under blurred image situation.

APA, Harvard, Vancouver, ISO, and other styles

49

Kang, Jinyoung, Donggyun Kim, and Joonki Paik. "Minimizing Ringing Artifact of Image Restoration Using Autocorrelation." TECHART: Journal of Arts and Imaging Science 2, no. 3 (2015): 31. http://dx.doi.org/10.15323/techart.2015.08.2.3.31.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Lettington, A. H., and Qi He Hong. "Ringing artifact reduction for Poisson MAP superresolution algorithms." IEEE Signal Processing Letters 2, no. 5 (1995): 83–84. http://dx.doi.org/10.1109/97.386284.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!