170,913 Hits in 5.4 sec

Scale-Space on Image Profiles about an Object Boundary [chapter]

Sean Ho, Guido Gerig
2003 Lecture Notes in Computer Science  
In this paper, we present a scale-space on image profiles taken about the object boundary, in an object-intrinsic coordinate system.  ...  Features from the scale-space are then used to build a statistical model of the image structure about the boundary, trained on a population of images with corresponding geometric models.  ...  This scale-space in an object-intrinsic coordinate system is then used to construct a statistical model of image structure about the object boundary, as trained on a population of segmented images.  ... 
doi:10.1007/3-540-44935-3_39 fatcat:5knjs2npafgenkmnqtfqik4ira

Profile Scale-Spaces for Multiscale Image Match [chapter]

Sean Ho, Guido Gerig
2004 Lecture Notes in Computer Science  
A spherical-harmonic based 3D shape representation provides a mapping of the object boundary to the sphere S 2 , and a scale-space for profiles on the sphere defines a scalespace on the object.  ...  A key feature is that profiles are not blurred across the object boundary, but only along the boundary.  ...  Image processing, including Figure 1 , by Rachel Gimpel. The formalism for a scale-space on S 2 arose from discussions with Remco Duits at the Technical University of Eindhoven.  ... 
doi:10.1007/978-3-540-30135-6_22 fatcat:w3gxiq5m4vawro7cmym33zejkq

Fusion of hyperspectral images and height models using edge probability

J. Avbelj, R. Muller, P. Reinartz
2013 2013 5th Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing (WHISPERS)  
The method is tested on an urban area, where building boundaries represent the high probabilities of an edge in both datasets.  ...  Edge probabilities are computed in scale-space and combined according to the Gaussian mixture model. The reliability of the datasets can be included into this model as a prior knowledge.  ...  Edge Detection An edge in an image is an abrupt change of intensity and represents a boundary between two regions.  ... 
doi:10.1109/whispers.2013.8080618 dblp:conf/whispers/AvbeljMR13 fatcat:anmimncwxjfcxbif55palksruq

A method and software for segmentation of anatomic object ensembles by deformable m-reps

Stephen M. Pizer, P. Thomas Fletcher, Sarang Joshi, A. Graham Gash, Joshua Stough, Andrew Thall, Gregg Tracton, Edward L. Chaney
2005 Medical Physics (Lancaster)  
The deformation process is driven by optimizing an objective function that has terms for the geometric typicality and model-to-image match for each instance of the deformed model.  ...  The success of this approach depends strongly on the object representation, i.e., the structural details and parameter set for the DSM, which in turn determines the analytic form of the objective function  ...  A gift from Intel Corp. provided computers on which some of this research was carried out. We thank Qiong Han, Conglin Lu, and Delphine Bull for help with models, figures, and references.  ... 
doi:10.1118/1.1869872 pmid:15984685 fatcat:5ikqw7yzwvayzjwbzsy3bb25ki

Projected Potential Profiles across Intergranular Glassy Films

Somnath BHATTACHARYYA, Christoph T. KOCH, Manfred RÜHLE
2006 Journal of the Ceramic Society of Japan  
For La 2 O 3 -MgO doped Si 3 N 4 , the potential profiles across the grainglassy pocket interface and the IGF were observed to be very similar and give very strong evidence for the existence of a space  ...  the electron exit face wave function from a series of defocused TEM images.  ...  the same imaging conditions to give the absorptive potential profile an absolute scale.  ... 
doi:10.2109/jcersj.114.1005 fatcat:f3bp3kzdebf6dhr4ybgv7khgdi

Evolutionary Deformable Models for Medical Image Segmentation: A Genetic Algorithm Approach to Optimizing Learned, Intuitive, and Localized Medial-Based Shape Deformation [chapter]

Chris McIntosh, Ghassan Hamarneh
2010 Genetic and Evolutionary Computation  
We present a novel evolutionary computing based approach to medical image segmentation.  ...  Furthermore, we constrain the evolution, and thus reduce the size of the search-space, by using statistically-based deformable models whose deformations are intuitive (stretch, bulge, bend) and driven  ...  edges and ill-equipped to handle gaps in object boundaries.  ... 
doi:10.1002/9780470973134.ch4 fatcat:ib6j2ogcdnbxfkoif4wvxs7r4y

Extraction of tumor region in color images using wavelets

Jiann-Der Lee, Yu-Lin Hsiao
2000 Computers and Mathematics with Applications  
Instead of the previous method, we propose an improved radial search technique to increase the accuracy of the extraction of the tumor border.  ...  In this paper, a wavelet-based method is proposed to extract the tumor region from a color medical image.  ...  The result profile after applying wavelet transform with scale 1, 2, 4, where curve S denotes original profile, curve 1 denotes scale 1, curve 2 denotes scale 2, and curve 4 denotes scale 4.large gap inside  ... 
doi:10.1016/s0898-1221(00)00197-8 fatcat:6x3jp6bsazaxxds63wudkgqhkm

Quantitative measurement of grain boundary potentials on the nanoscale by off-axis electron holography

M. A. Schofield, L. Wu, Y. Zhu
2003 Physical Review B (Condensed Matter)  
We measure an average grain boundary potential of 2.18Ϯ0.12 V corresponding to about a 8.6 Å interface width, and conclude that a negative charge of 1.7e Ϫ /unit cell is associated with the grain boundary  ...  We further examine the effect of objective lens aberration and defocus on the potential quantification for subnanometer resolution and conclude that it may be neglected for spatial resolution above 5 Å  ...  Spatial resolution It is conventional to describe the objective lens aberration and defocus by multiplication of the object wave object (q) in reciprocal space by a phase factor (q) such that the image  ... 
doi:10.1103/physrevb.67.224512 fatcat:orqp3ct5mfdh7nxv3iizuiwwea

Reassembling Thin Artifacts of Unknown Geometry [article]

Geoffrey Oxholm, Ko Nishino
2011 VAST: International Symposium on Virtual Reality  
Unlike past methods, we do not make any restrictive assumptions about the geometry or texture of the object.  ...  We begin by encoding the scale variability of each fragment's boundary contour in a multi-channel, 2D representation.  ...  We derive an image registration method based on this scale-space boundary contour representation to rapidly identify matching sub-contours.  ... 
doi:10.2312/vast/vast11/049-056 fatcat:tnvbitcy35fgrgtdt65xth4qgi

Simultaneous Object Detection and Segmentation by Boosting Local Shape Feature based Classifier

Bo Wu, Ram Nevatia
2007 2007 IEEE Conference on Computer Vision and Pattern Recognition  
The system is evaluated on a number of public image sets and compared with several previous methods.  ...  This paper proposes an approach to simultaneously detect and segment objects of a known category. Edgelet features are used to capture the local shape of the objects.  ...  The training procedure needs about 72 hours. For single-scale detection and segmentation, the speed is about 200ms per image. For multi-scale, it is about 600ms per image.  ... 
doi:10.1109/cvpr.2007.383042 dblp:conf/cvpr/WuN07 fatcat:sfnm6r6xlng2tc2lme3tfqrzee

3-D Active Shape Image Segmentation Using a Scale Model

Seong-jae Lim, Yo-sung Ho
2006 2006 IEEE International Symposium on Signal Processing and Information Technology  
In this paper, we propose an active shape image segmentation method for three-dimensional (3-D) medical images.  ...  Scale models are more compact, have more information in the region close to boundary, and have less information in the region far away from the boundary.  ...  Each CT image contains up to 71 image slices with an interslice spacing of 3.8mm.  ... 
doi:10.1109/isspit.2006.270791 fatcat:nx6pezpzxfd2redx2lewmgjjte

A Generic Probabilistic Active Shape Model for Organ Segmentation [chapter]

Andreas Wimmer, Grzegorz Soza, Joachim Hornegger
2009 Lecture Notes in Computer Science  
With an average surface distance of 1.0 mm and an average volume overlap error of 6.5 %, it outperforms other automatic methods and provides accuracy close to interactive ones.  ...  In particular, a nearest neighbor boundary appearance model is complemented by a cascade of boosted classifiers for region information and combined with a shape model based on Parzen density estimation  ...  The whole process ran without user interaction and took about 3 min. per image on a 3 GHz CPU.  ... 
doi:10.1007/978-3-642-04271-3_4 fatcat:qkpg5u42a5am5hyoios25r7hri

Application of electromagnetic field modelling in GPR investigations of an historic tenement

Klaudia Czaja
2012 Geology Geophysics & Environment  
The wave field recorded on profile P4 can be divided into two parts, with the boundary between them situated about 5 m from the starting point of the profile.  ...  One may notice the hyperbola at a depth of about one meter and a distance of about 2 m on the echograms from profile P3 (Figs 2, 3).  ... 
doi:10.7494/geol.2012.38.4.395 fatcat:izdexfgqaze7xhhchurkstssaa

Microwave propagation over the Earth: image inversion

Nev Fowkes, Brett Nener
2005 Journal of Engineering Mathematics  
Also note . 7. . . . 1zo(1.yo that the resulting scaled magnification is given by see = 1, so that equally spaced mark- ings on the lighthouse will be seen as equally spaced markings in the image plane  ...  Note that, if an observer and object are located on opposite sides of an intersection point, then the observer will see an inverted image of the object; mirages are possible.  ... 
doi:10.1007/s10665-005-9015-0 fatcat:cjelkjxwljaz3ia6mihoin4qym

Encoding contour shape by curvature extrema

Whitman Richards, Benjamin Dawson, Douglas Whittington
1986 Optical Society of America. Journal A: Optics, Image Science, and Vision  
To handle the scale problem, we use an adaptation of Witkin's scale space. Our algorithm differs from Witkin's by using a notion of parts to set criteria for significant structures.  ...  Curvature extrema provide significant information about the shape of an image contour, such as a silhouette, and are the basis for the Hoffman-Richards codon representation for shape.  ...  Part boundaries must therefore be specified at a scale. How do we find this scale? Will this choice be a subjective one or will it indeed reflect the actual structure of the object?  ... 
doi:10.1364/josaa.3.001483 pmid:3761053 fatcat:nkznnbbbybdifmvpbf6u5v4mwu
« Previous Showing results 1 — 15 out of 170,913 results