Editing Scheme Research Articles

FreeScup: A Novel Platform for Assisting Sculpture Pose Design

Sculpture design is challenging due to its inherent difficulty in characterizing artworks quantitatively; thus, few works have been done to assist sculpture design in the past decades in the multimedia community. We have cooperated with several sculptors on analyzing styles of different artists consisting of Giacometti, Augeuste Rodin, Henry Moore, and Marino Marini from which we find pose editing plays an important role in sculpture design. Motivated by this, we present a novel platform that allows sculptors to edit virtual three-dimensional (3-D) sculptures by a free way. The proposed platform consists of three modules, namely, sculpture initialization , sculptor-sculpture mapping , and interactive pose editing . In sculpture initialization, a virtual 3-D sculpture is first incrementally reconstructed from multiview images. Then, we define Laplace operator and its corresponding spectrum to describe the geometry information of the reconstructed sculpture. During sculptor–sculpture mapping, we apply spectral analysis on the low-frequency parts of the spectrum to search for candidate editing points on the surface of the sculpture. Next, body actions of the sculptor are captured by Kinect and further mapped onto editing points as a predefined configuration set. Finally, during interactive pose editing, a real-time Kinect-driven sculpture pose editing scheme is presented, which not only preserves geometry features of the sculpture but also allows instant changes of sculpture poses. We demonstrate that our platform successfully assists sculptors on real-time pose editing by comparing its performance with those of the existing sculpture assisting methods.

A rapid inversion technique for the measurement of longitudinal relaxation times of brain metabolites: application to lactate in high-grade gliomas at 3 T.

The aim of this study was to develop a time-efficient inversion technique to measure the T1 relaxation time of the methyl group of lactate (Lac) in the presence of contaminating lipids and to measure T1 at 3 T in a cohort of primary high-grade gliomas. Three numerically optimized inversion times (TIs) were chosen to minimize the expected error in T1 estimates for a given input total scan duration (set to be 30 min). A two-cycle spectral editing scheme was used to suppress contaminating lipids. The T1 values were then estimated from least-squares fitting of signal measurements versus TI. Lac T1 was estimated as 2000 ± 280 ms. After correcting for T1 (and T2 from literature values), the mean absolute Lac concentration was estimated as 4.3 ± 2.6 mm. The technique developed agrees with the results obtained by standard inversion recovery and can be used to provide rapid T1 estimates of other spectral components as required. Lac T1 exhibits similar variations to other major metabolites observable by MRS in high-grade gliomas. The T1 estimate provided here will be useful for future MRS studies wishing to report relaxation-corrected estimates of Lac concentration as an objective tumor biomarker. Copyright © 2016 John Wiley & Sons, Ltd.

Structure-altering feature-based triangle mesh model editing for primitive-based engineering parts

This paper presents a structure-altering feature-based editing scheme for triangle mesh models of primitives for engineering application. With the increasing usage of 3D scanning and 3D printing technologies in product design, triangle mesh has become a vital model format in engineering designs. Coupled with its flexible nature in shape manipulation, many design models are now constructed in a mesh form. However, methods to perform direct feature-based mesh model modifications are lacking. Editing features and their defining parameters is greatly underdeveloped for mesh models compared with their parametric model counterparts. Thus, the proposed scheme aims to enable structure-altering feature-based mesh editing through the imposition (mapping) of a feature information layer on top of the triangle mesh model. Feature-based editing is done on the feature information layer. Through information mapping, the mesh model adapts to changes in the feature information layer, resulting in a geometric representation that accurately reflects the feature information layer content. Large-scale model modifications with structure-altering edits are thus achievable for mesh models, allowing straightforward feature-based model editing without the loss of the flexible mesh representation. Numerous case studies have been done to illustrate the effectiveness of the presented feature-based editing scheme.

Geometry seam carving

We present a novel approach to feature-aware mesh deformation. Previous mesh editing methods are based on an elastic deformation model and thus tend to uniformly distribute the distortion in a least-squares sense over the entire deformation region. Recent results from image resizing, however, show that discrete local modifications such as deleting or adding connected seams of image pixels in regions with low saliency lead to far superior preservation of local features compared to uniform scaling — the image retargeting analog to least-squares mesh deformation. Hence, we propose a discrete mesh editing scheme that combines elastic as well as plastic deformation (in regions with little geometric detail) by transferring the concept of seam carving from image retargeting to the mesh deformation scenario. A geometry seam consists of a connected strip of triangles within the mesh’s deformation region. By collapsing or splitting the interior edges of this strip, we perform a deletion or insertion operation that is equivalent to image seam carving and can be interpreted as a local plastic deformation. We use a feature measure to rate the geometric saliency of each triangle in the mesh and a well-adjusted distortion measure to determine where the current mesh distortion asks for plastic deformations, i.e., for deletion or insertion of geometry seams. Precomputing a fixed set of low-saliency seams in the deformation region allows us to perform fast seam deletion and insertion operations in a predetermined order such that the local mesh modifications are properly restored when a mesh editing operation is (partially) undone. Geometry seam carving hence enables the deformation of a given mesh in a way that causes stronger distortion in homogeneous mesh regions while salient features are preserved much better.

An improved fast edit approach for two-string approximated mean computation applied to OCR

This paper presents a new fast algorithm for computing an approximation to the mean of two strings of characters representing a 2D shape and its application to a new Wilson-based editing procedure. The approximate mean is built up by including some symbols from the two original strings. In addition, a Greedy approach to this algorithm is studied, which allows us to reduce the time required to compute an approximate mean. The new dataset editing scheme relaxes the criterion for deleting instances proposed by the Wilson editing procedure. In practice, not all instances misclassified by their near neighbors are pruned. Instead, an artificial instance is added to the dataset in the hope of successfully classifying the instance in the future. The new artificial instance is the approximated mean of the misclassified sample and its same-class nearest neighbor.Experiments carried out over three widely known databases of contours show that the proposed algorithm performs very well when computing the mean of two strings, and outperforms methods proposed by other authors. In particular, the low computational time required by the heuristic approach makes it very suitable when dealing with long length strings. Results also show that the proposed preprocessing scheme can reduce the classification error in about 83% of trials. There is empirical evidence that using the Greedy approximation to compute the approximated mean does not affect the performance of the editing procedure.

Macromolecule‐suppressed GABA‐edited magnetic resonance spectroscopy at 3T

Edited magnetic resonance spectroscopy makes possible noninvasive studies of the role of the inhibitory neurotransmitter GABA in the healthy brain and in disease processes. A major limitation of the methodology is coediting of macromolecular signals. Although it has previously been shown that macromolecular signal can be suppressed using a symmetrical editing scheme, this approach is rarely applied at field strength of 3T as insufficiently selective pulses result in loss of GABA signal (in addition to the intended suppression of macromolecular signal). In this article, the authors show that increasing the echo time to 80 ms lets more selective editing pulses be used, allowing for symmetric editing-based suppression of coedited macromolecular signal without loss of GABA signal. The method is applied to acquire macromolecule-suppressed GABA-edited spectra in 10 healthy participants.

Efficient γ‐aminobutyric acid editing at 3T without macromolecule contamination: MEGA‐SPECIAL

One of the most commonly used methods for in vivo MRS detection of γ-aminobutyric acid (GABA) is the MEGA-point-resolved spectroscopy (MEGA-PRESS) technique. However, accurate quantification of GABA using MEGA-PRESS is complicated by spectral co-editing of macromolecular resonances. In this article, a new pulse sequence is presented which enables GABA editing at 3T with the removal of macromolecule contamination. This sequence combines the conventional MEGA editing scheme with the SPECIAL localisation technique, and is therefore named MEGA-SPECIAL. Simulations and phantom experiments indicate that this new approach provides improved GABA editing efficiency relative to MEGA-PRESS, and in vivo results demonstrate effective removal of macromolecule contamination. In a study of the occipital lobe of five healthy volunteers, the macromolecule-corrected GABA/creatine ratio was found to be 0.093 ± 0.007 (mean ± standard deviation), whereas prior to macromolecule correction, the ratio was found to be 0.173 ± 0.013.

MR spectroscopic imaging of glutathione in the white and gray matter at 7 T with an application to multiple sclerosis

Detection of glutathione (GSH) is technically challenging at clinical field strengths of 1.5 or 3 T due to its low concentration in the human brain coupled with the fact that conventional single-echo acquisitions, typically used for magnetic resonance (MR) spectroscopy acquisitions, cannot be used to resolve GSH given its overlap with other resonances. In this study, an MR spectral editing scheme was used to generate an unobstructed detection of GSH at 7 T. This technique was used to obtain normative white (WM) and gray matter (GM) GSH concentrations over a two-dimensional region. Results indicated that GSH was significantly higher (P<.001) in GM relative to WM in normal subjects. This finding is consistent with previous radionuclide experiments and histochemical staining and validates this 7 T MR spectroscopy technique. To our knowledge, this is the first study to report normative differences in WM and GM glutathione concentrations in the human brain. Glutathione is a biomarker for oxidative status and this non-invasive in vivo measurement of GSH was used to explore its sensitivity to oxidative state in multiple sclerosis (MS) patients. There was a significant reduction (P<.001) of GSH between the GM in MS patients and normal controls. No statistically significant GSH differences were found between the WM in controls and MS patients. Reduced GSH was also observed in a MS WM lesion. This preliminary investigation demonstrates the potential of this marker to probe oxidative state in MS.

Selective resonance suppression1H-[13C] NMR spectroscopy with asymmetric adiabatic RF pulses

Despite obvious improvements in spectral resolution at high magnetic field, the detection of 13C labeling by 1H-[13C] NMR spectroscopy remains hampered by spectral overlap, such as in the spectral region of 1H resonances bound to C3 of glutamate (Glu) and glutamine (Gln), and C6 of N-acetylaspartate (NAA). The aim of this study was to develop, implement, and apply a novel 1H-[13C] NMR spectroscopic editing scheme, dubbed "selective Resonance suppression by Adiabatic Carbon Editing and Decoupling single-voxel STimulated Echo Acquisition Mode" (RACED-STEAM). The sequence is based on the application of two asymmetric narrow-transition-band adiabatic RF inversion pulses at the resonance frequency of the 13C coupled to the protons that need to be suppressed during the mixing time (TM) period, alternating the inversion band downfield and upfield from the 13C resonance on odd and even scans, respectively, thus suppressing the detection of 1H resonances bound to 13C within the transition band of the inversion pulse. The results demonstrate the efficient suppression of 1H resonances bound to C3 of Glu and Gln, and C4 of Glu, which allows the 1H resonances bound to C6 of NAA and C4 of Gln to be revealed. The measured time course of the resolved labeling into NAA C6 with the new scheme was consistent with the slow turnover of NAA.

J‐difference lactate editing at 3.0 Tesla in the presence of strong lipids

To implement in vivo detection of lactate in the presence of lipids by proton magnetic resonance spectroscopy at a 3 Tesla (T) field strength for potential applications in human tumors outside of the brain. The BASING J-difference sequence was implemented in the presence of high lipid concentrations in phantoms and in vivo at 3 Tesla. The effectiveness of the lactate editing scheme is demonstrated in phantoms containing both lactate and lipids and in vivo in ischemic induced human muscle. The ability of the BASING J-difference technique to detect lactate in the presence of strong lipid signals outside the brain at 3T is feasible. This robust technique should permit noninvasive lactate measurements in human tumors to investigate its potential as a prognostic indicator.

Adaptive sampling for mesh spectrum editing

A mesh editing framework is presented in this paper, which integrates Free-Form Deformation (FFD) and geometry signal processing. By using simplified model from original mesh, the editing task can be accomplished with a few operations. We take the deformation of the proxy and the position coordinates of the mesh models as geometry signal. Wavelet analysis is employed to separate local detail information gracefully. The crucial innovation of this paper is a new adaptive regular sampling approach for our signal analysis based editing framework. In our approach, an original mesh is resampled and then refined iteratively which reflects optimization of our proposed spectrum preserving energy. As an extension of our spectrum editing scheme, the editing principle is applied to geometry details transferring, which brings satisfying results.

Adaptive extraction of highlights from a sport video based on excitement modeling

This paper addresses the challenge of automatically extracting the highlights from sports TV broadcasts. In particular, we are interested in finding a generic method of highlights extraction, which does not require the development of models for the events that are thought to be interpreted by the users as highlights. Instead, we search for highlights in those video segments that are expected to excite the users most. It is namely realistic to assume that a highlighting event induces a steady increase in a user's excitement, as compared to other, interesting events. We mimic the expected variations in a user's excitement by observing the temporal behavior of selected audiovisual low-level features and the editing scheme of a video. Relations between this noncontent information and the evoked excitement are drawn partly from psychophysiological research and partly from analyzing the live-video directing practice. The expected variations in a user's excitement are represented by the excitement time curve, which is, subsequently, filtered in an adaptive way to extract the highlights in the prespecified total length and in view of the preferences regarding the highlights strength: extraction can namely be performed with variable sensitivity to capture few highlights or more less strong ones. We evaluate and discuss the performance of our method on the case study of soccer TV broadcasts.

Brain GABA editing without macromolecule contamination.

A new scheme is proposed to edit the 3.0 ppm GABA resonance without macromolecule (MM) contamination. Like previous difference spectroscopy approaches, the new scheme manipulates J-modulation of this signal using a selective editing pulse. The elimination of undesirable MM contribution at 3.0 ppm is obtained by applying this pulse symmetrically about the J-coupled MM resonance, at 1.7 ppm, in the two steps of the editing scheme. The effectiveness of the method is demonstrated in vitro, using lysine to mimic MM, and in vivo. As compared to the most commonly used editing scheme, which necessitates the acquisition and processing of two distinct difference spectroscopy experiments, the new scheme offers a reduction in experimental time (-33%) and an increase in accuracy. Magn Reson Med 45:517-520, 2001.

A Spin System Labeled and Highly Resolved ed-H(CCO)NH-TOCSY Experiment for the Facilitated Assignment of Proton Side Chains in Partially Deuterated Samples.

The introduction of deuterated and partially deuterated protein samples has greatly facilitated the 13C assignment of larger proteins. Here we present a new version of the HC(CO)NH-TOCSY experiment, the ed-H(CCO)NH-TOCSY experiment for partially deuterated samples, introducing a multi-quantum proton evolution period. This approach removes the main relaxation source (the dipolar coupling to the directly bound 13C spin) and leads to a significant reduction of the proton and carbon relaxation rates. Thus, the indirect proton dimension can be acquired with high resolution, combined with a phase labeling of the proton resonances according to the C-C spin system topology. This editing scheme, independent of the CHn multiplicity, allows to distinguish between proton side-chain positions occurring within a narrow chemical shift range. Therefore this new experiment facilitates the assignment of the proton chemical shifts of partially deuterated samples even of high molecular weights, as demonstrated on a 31 kDa protein.

Spectroscopic and Kinetic Studies of the Histidine Residues of Bovine Low-Molecular-Weight Phosphotyrosyl Protein Phosphatase

The role of the two conserved histidine residues in the low-molecular-weight phosphotyrosyl protein phosphatases was investigated using site-directed mutagenesis of the recombinant bovine heart enzyme. His-66 and His-72 were individually mutated to alanine and to asparagine. A double mutant, containing only alanines in place of the histidines, was also created. The 1H NMR spectra of the purified proteins revealed no apparent tertiary structure alterations. Microscopic pKas for the two histidines were determined from a pH titration of the wild-type enzyme using 1H NMR spectroscopy and an MLEV-17 spectral editing scheme to more readily follow shifts in the specific histidine resonance peaks. His-66 titrates with an apparent pKa of 8.4 while for His-72 the value is 9.2. Since earlier chemical modification experiments indicated that the wild-type enzyme was inactivated by the histidine-selective modification reagent diethyl pyrocarbonate (DEP), the histidine mutants were tested for sensitivity to DEP. Both of the histidine single mutants were inactivated by DEP, and surprisingly, the double mutant containing no histidines was also readily inactivated by DEP. Thus, for this protein, modification by DEP is not specific for histidine residues. Kinetic studies of the mutant proteins reveal that neither histidine is essential in the catalytic mechanism. His-66 mutants showed virtually identical catalytic properties compared to wild-type enzyme, whereas His-72 mutants had reduced specific activity and higher phosphate Ki and lower Km values at pH5 and higher. It is proposed that His-72, although not essential for catalysis, may serve a significant structural role at the enzyme active site.

Identification and pKa determination of the histidine residues of human low-molecular-weight phosphotyrosyl protein phosphatases: A convenient approach using MLEV-17 spectral editing scheme

A useful approach using an MLEV-17 pulse sequence was developed to identify histidine C epsilon 1H magnetic resonances of proteins. This technique can be readily applied to proteins dissolved directly in deuterium oxide solution and eliminates the necessity for an exhaustive exchange of NH to ND. Because of its sensitivity, this technique makes it possible to significantly extend the limitations on protein size. The utility of this spin-lock sequence is demonstrated using ribonuclease, subtilisin, and human prostatic acid phosphatase, with molecular weights ranging from 12K to 100K. With this technique, all three or four of the histidine 1H NMR signals of two human low-molecular-weight phosphotyrosyl protein phosphatases (HCPTP-A or -B, respectively) were readily detected. Histidine peak assignments were accomplished through the use of histidine to alanine mutants of HCPTP-A and -B and a homologous bovine enzyme. Analysis of the pH titration curves of these signals provided microscopic pKa's for the histidines in the human enzymes. A comparison of corresponding histidine pKa values of the two isoenzymes, together with an examination of the 1H NMR spectra of the proteins, provided evidence of significant differences in secondary structure. Titration of HCPTP-A and -B with vanadate, a strongly bound competitive inhibitor, caused the His-72 peak to appear as two signals at nearly equimolar concentrations of protein and vanadate, while the other histidine peaks were not affected. This is interpreted to mean that His-72 is at the enzyme active site.

Lactate distribution in ischemic rat kidney by 4D spectroscopic imaging.

A lactate map of the rat kidney is presented, using a four-dimensional spectroscopic imaging technique in connection with a double resonance editing scheme. A voxel size of 12 microL has been obtained, and we show that eddy currents do not affect the line shape of an individual voxel.

A one-shot lactate-editing sequence for localized whole-body spectroscopy.

A pulse sequence is presented for performing localized lactate-edited proton spectroscopy in the whole-body environment. The sequence is optimized for relatively low field strength (1.5-T) clinical measurements. Characteristics of this method of lactate editing, which makes it more suitable for clinical applications than previous methods, include the following: The "one shot" nature of the method makes it relatively insensitive to patient motion; water suppression is high as all 90 degrees pulses are binomial pulses; and very narrow band rf pulses, such as used in high-field lactate-editing sequences, but which are necessarily very long at low fields, are not required. Further, this lactate editing scheme can be very easily combined with localized spectroscopic measurements.

The application of composite pulses to surface-coil NMR

The application of composite pulses to surface-coil NMR is discussed theoretically and verified experimentally. The composite pulses are constructed using the scheme of Levitt and Ernst. Phase anomalies due to the use of composite pulses with an inhomogeneous H 1 are eliminated by cycling the phases of the pulses. The observed magnetization as a function of pulse angle produced by the composite pulse is calculated and verified experimentally. The composite-pulse spin-echo sequence is applied to a 1H homonuclear editing scheme to obtain an edited spectrum of lactate from the brain of an intact rat using a surface coil. An increase in the S N ratio is observed with a decrease in the magnitude of J-modulation anomalies.

On-line multi-unit sorting with resolution of superposition potentials

An on-line sorting system for multi-unit records is described which solves the problem of the resolution of superposition potentials. A segment of record up to 17 sec long, sampled at 8.3 kc/sec, is continuously stored on digital tape. A backwards and forwards scanning display facility is used by the operator to select up to four units representative of those he desires to analyse. A high-speed scanning operation compares all of the subsequent units in the record with the representative “templates”. Well matching units are automatically accepted and update their appropriate templates. For dissimilar units (usually superposition potentials) a first-order resolution into components is attempted and, if this is unsuccessful, their locations are marked and their “contemporary” templates are stored. After this scan, the systematically recalled superposition potentials are resolved by the operator using two special display facilities. An editing scheme whereby the original recording may be searched for suspected errors ensures error-free interval-time plots. A record of 10 sec duration, in which three different units are to be analysed, might require a total analysis time of 60 sec. The program, written for a DEC PDP-12 with an 8K memory and an Extended Arithmetic Element, is available from the author. In principle, the system is adaptable for any comparable laboratory computer with digital tape or disc systems.