[[start]]
 
Trace: » start

INDEX

Table of Contents

Welcome to the VIGIL Community!!!

This is the bunch of folks dabbling with images, and more recently media of all kind. The whole idea is that it doesn't make sense to do computing, if you don't do visual computing.

Well, that said, this image will give you the general idea.

News

  • Paper on “Tracing Specular Light Paths in Point Based Scenes” by Rhushabh Goradia, Sriram Kashyap, Parag Chaudhuri, Sharat Chandran gets accepted in The Visual Computer Journal, 2011. This is an extension of their previous work “Implicit Surface Octrees for Ray Tracing Point Models” published at ICVGIP 2010, Seventh Indian Conference on Computer Vision, Graphics and Image Processing.
  • Paper on “Resolving Occlusion in Multiframe Reconstruction of Deformable Surfaces” by Appu Shaji, Aydin Varol, Pascal Fua, Yashoteja Prabhu, Ankush Jain, Sharat Chandran gets accepted in the CVPR Workshops (NORDIA), 2011 in Colorado Springs
  • Paper on “Projection Defocus Correction using Adaptive Kernel Sampling and Geometric Correction in Dual-planar Environments” by Shamsuddin Ladha, Sharat Chandran, and Kate Smith-Miles gets accepted at PROCAMS 2011, 8th IEEE International Workshop on Projector–Camera Systems
  • Paper on “Image-Based Animation” by Biswarup Choudhury and Ambareesha R. was presented at International Conference in Central Europe on Computer Graphics, Visualization and Computer Vision'2011 (WSCG'11), Plzen, Czech Republic, January 31 - February 3, 2011 by Ambareesha.
  • Paper on “Implicit Surface Octrees for Ray Tracing Point Models” by Sriram Kashyap, Rhushabh Goradia, Parag Chaudhuri, Sharat Chandran gets an HONORARY MENTION at ICVGIP 2010, Seventh Indian Conference on Computer Vision, Graphics and Image Processing.
  • Paper on “Implicit Surface Octrees for Ray Tracing Point Models” by Sriram Kashyap, Rhushabh Goradia, Parag Chaudhuri, Sharat Chandran gets accepted at ICVGIP 2010, Seventh Indian Conference on Computer Vision, Graphics and Image Processing.
  • Paper on “GPU-Based Ray Tracing of Splats” by Rhushabh Goradia, Sriram Kashyap, Parag Chaudhuri, Sharat Chandran gets accepted at Pacific Graphics 2010, 18th Pacific Conference on Computer Graphics and Applications
  • Paper on “Rendering Wave Effects with Augmented Light Field,''}} (Se Baek Oh, Sriram Kashyap, Rohit Garg, and Ramesh Raskar). Computer Graphics Forum 29(2):507–516, 2010 has been accepted at Eurographics 2010.
  • Poster on “Real Time Ray Tracing of Point-Based Models” by Sriram Kashyap, Rhushabh Goradia, Parag Chaudhuri, and Sharat Chandran gets accepted at ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games, February 2010.

[Earlier]

  • Aniruddha Joshi's poster “Hybrid SVM for Multiclass Arrhythmia Classification” gets selected for a presentation in Microsoft's TechVista 2010 held in Bangalore on 22nd January, 2010.
  • Aniruddha J. Joshi's paper “Hybrid SVM for Multiclass Arrhythmia Classification” has been accepted in International Journal of Functional Informatics and Personalised Medicine (IJFIPM) (2010). Also appears in proceedings of IEEE International Conference on Bioinformatics & Biomedicine. Please see http://www.ittc.ku.edu/bioinformatics/BIBM09/home.php for more details on the conference.
  • Andrew Janowczyk's paper “Hierarchical Normalized Cuts: Unsupervised Segmentation of Vascular Biomarkers from Ovarian Cancer Tissue Microarrays” has been accepted as an oral presentation atMICCAI 2009.
  • Andrew Janowczyk's paper “Fast, Processor-Cardinality Agnostic PRNG with a Tracking Application” wins the best poster prize at ICVGIP 2008
  • Congratulations to http://www.cse.iitb.ac.in/~amod Amod Jog whose paper “Classifying Ayurvedic Pulse Signals Via Consensus Locally Linear Embedding” has been accepted as an oral presentation at Biosignals 2009.
  • Rhushabh Goradia/Prekshu Ajmera's poster on GPU-based Global Illumination of Point Models using Fast Multipole Method wins the first prize at TechVista 2008
  • Paper on “Fast, Processor-Cardinality Agnostic PRNG with a Tracking Application by Andrew Janowczyk gets accepted at the Sixth Indian Conference on Vision, Graphics and Image Processing (ICVGIP) 2008. See http://www.icvgip.org for more details on the conference.
  • Biswarup Choudhury's poster “Images: a new computer graphics primitive” gets selected for a presentation in Microsoft's TechVista 2008 to be held in Chennai on 1st October, 2008.
  • Rhushabh Goradia/Prekshu Ajmera's poster on GPU-based Global Illumination of Point Models using Fast Multipole Method gets selected for a presentation in Microsoft's TechVista 2008 to be held in Chennai on 1st October, 2008.
  • 3 Papers from ViGIL gets accepted at ICPR
    1. Manifold Optimisation for Motion Factorisation by Appu Shaji, Sharat Chandran and David Suter
    2. “Arterial Pulse Rate Variability Analysis for Diagnoses” by Aniruddha Joshi, Sharat Chandran, Valadi Jayaraman and Bhaskar Kulkarni
    3. “Multifractality in Arterial Pulse” by Aniruddha Joshi, Sharat Chandran, Valadi Jayaraman and Bhaskar Kulkarni
  • 2 Papers from ViGIL gets accepted at IEEE EMBC 2007
    1. “Nadi Tarangini: A pulse based diagnostic system” by Aniruddha Joshi, Sharat Chandran, Valadi Jayaraman and Bhaskar Kulkarni
    2. “Arterial pulse system: Modern methods for traditional Indian medicine” by Aniruddha Joshi, Sharat Chandran, Valadi Jayaraman and Bhaskar Kulkarni

Latest Papers

Tracing Specular Light Paths in Point Based Scenes
(Rhushabh Goradia, Sriram Kashyap, Parag Chaudhuri, Sharat Chandran) accepted at The Visual Computer 2011
Massive point data sets representing meticulous details of various heritage sites and statues are now becoming available due to recent advances in multi-view stereo techniques. Photo-realistic rendering of such point sets have not yet, however, matched their polygonal counterparts with respect to the interactivity of applications as well as the quality of light simulations. In this paper, we present a framework for tracing specular light paths in massive point model environments at interactive frame rates on Graphics Processing Units (GPUs). We introduce the Sample Octree (S-Octree), a lightweight data structure for efficient, sampled representation of point set information. The Implicit Surface Octree (ISO), an instance of the S-Octree provides a compact representation of point set surfaces. The ISO defines a local manifold approximation of the input point data. The Caustic Sample Map (CSM), another instance of the S-Octree, represents contributions of caustic paths. These data structures enable us to further the state of the art by demonstrating reflections, refractions, shadows and caustic effects on massive, complex point models at interactive frame rates.
Resolving Occlusion in Multiframe Reconstruction of Deformable Surfaces
(Appu Shaji, Aydin Varol, Pascal Fua, Yashoteja Prabhu, Ankush Jain, Sharat Chandran)
accepted at NORDIA @ CVPR 2011
Projection Defocus Correction using Adaptive Kernel Sampling and Geometric Correction in Dual-planar Environments
( Shamsuddin N. Ladha, Sharat Chandran, Kate Smith-Miles)
accepted at PROCAMS 2011, 8th IEEE International Workshop on Projector–Camera Systems
Defocus blur correction for projectors using a camera is useful when the projector is used in ad hoc environments. However, past literature has not explicitly considered the common situation when the projection surface includes a corner made up of two planar surfaces that abut each other, such as the ubiquitous office cubicle. In this paper, we advance the state of the art by demonstrating defocus correction in a non-parametric setting. Our method differs from prior methods in that (1) the luminance and chrominance channels are independently considered, and (2) a sparse sampling of the surface is used to discover the spatially varying defocus kernel.
Implicit Surface Octrees For Ray Tracing Point Models -- Honorable Mention
(Sriram Kashyap, Rhushabh Goradia, Parag Chaudhuri, Sharat Chandran) accepted at ICVGIP 2010, Seventh Indian Conference on Computer Vision, Graphics and Image Processing, 2010|ICVGIP 2010, Seventh Indian Conference on Computer Vision, Graphics and Image Processing, Chennai, 2010
Point-based representations of objects have been used as modeling alternatives to the almost ubiquitous quads or triangles. However, our ability to render these points has not matched their polygonal counterparts when we consider both rendering time and sophisticated lighting effects. In this paper, we present a framework for ray tracing massive point model environments at interactive frame rates on the Graphic Processing Units (GPUs). We introduce the Implicit Surface Octree (ISO), a lightweight data structure for efficient representation of point set surfaces. ISOs provide a compact local manifold approximation of the input point data and can also be embellished with lighting information. This enables us to further the state of the art by demonstrating reflections, refractions and shadow effects on complex point models at interactive frame rates.
Topological Invariants of Arterial Pulse Signals
( Aniruddha J. Joshi, Sharat Chandran, Dr. V.K. Jayaraman, Dr. B.D. Kulkarni)
accepted at PAKDD Workshop on Data Mining for Healthcare Management, 2010
Many important time series such as those originating from weather patterns, stock market trends, and biomedical signals contain a pseudo-periodic nature where the nature of shrinking and stretching is an indication of the information content. Topological invariants with its basis in non-linear dynamics and chaos theory can be considered as a concise indicator of the measure of these changes. In this paper, the time series obtained from the arterial pulse signal is analyzed using measures such as linking numbers, and relative rotation rates. We provide a simple computational paradigm in analyzing any time series using the pulse as an example, and advocate a novel use of the signal with the minimum distance criterion and the big orbit criterion. The quantitative condensation of enormous data in this manner has many potential uses in the classification.
Vision Assisted Safety Enhanced Shooting Range Simulator
( Shamsuddin N. Ladha, Sharat Chandran, Kate Smith-Miles)
accepted at National Conference on Computer Vision, Pattern Recognition, Image Processing and Graphics, 2010
Traditional shooting range simulators involve large investment in real estate, and other infrastructural resources. This paper describes a novel application of projector-camera systems to create a virtual shooting range. Projector-based display systems offer an attractive combination of dense pixels over large regions. When coupled with a camera, the feedback system enables the display to be adjusted to environments enabling a variety of applications. We analyse two different implementation approaches for the simulator. As compared to a traditional shooting range, our simulator is inexpensive, safe and eco-friendly.
Hybrid SVM for Multiclass Arrhythmia Classification
( Aniruddha J. Joshi, Sharat Chandran, Dr. V.K. Jayaraman, Dr. B.D. Kulkarni)
accepted at IEEE International Conference on Bioinformatics & Biomedicine (BIBM) , 2009
We propose a Holder-SVM detection algorithm using a novel hybrid arrangement of binary and multiclass SVMs designed to take care of class imbalance rampant in biomedical signals. As a result, we significantly reduce the number of false negatives – patients falsely classified as normal. We used the MIT-BIH Arrhythmia database for seven different arrhythmias. We compare our hybrid SVM with a suitable conventional SVM, and show better results. We also use the new arrangement for features proposed earlier, and demonstrate the gain in accuracy. Our concept of hybrid SVM is applicable to a wide variety of multiclass classification problems.
Hierarchical Normalized Cuts: Unsupervised Segmentation of Vascular Biomarkers from Ovarian Cancer Tissue Microarrays
(Andrew Janowczyk, Sharat Chandran, Rajendra Singh, Dimitra Sasaroli, George Coukos, Michael D. Feldman, and Anant Madabhushi) accepted at Medical Image Computing and Computer Assisted Intervention Society (MICCAI) , 2009
Research has shown that tumor vascular markers (TVMs) may serve as potential OCa biomarkers for prognosis prediction. The ability to quickly and quantitatively estimate vascular stained regions may yield an image based metric linked to disease survival and outcome. In this paper, we present a general, robust and efficient unsupervised segmentation algorithm, termed Hierarchical Normalized Cuts (HNCut), and show its application in precisely quantifying the presence and extent of a TVM on OCa TMAs. The strength of HNCut is in the use of a hierarchically represented data structure that bridges the mean shift (MS) and the normalized cuts (NCut) algorithms. This allows HNCut to efficiently traverse a pyramid of the input image at various color resolutions, efficiently and accurately segmenting the object class of interest (in this case ESM-1 vascular stained regions) by simply annotating half a dozen pixels belonging to the target class.
Manifold Optimisation for Motion Factorisation
(Appu Shaji , Sharat Chandran and David Suter) accepted at International Conference on Pattern Recognition , 2008
This paper presents a novel formulation for the popular factorisation based solution for Structure from Motion. Since our measurement matrices are populated with incomplete and inaccurate data, SVD based total least squares solution are less than appropriate. Instead, we approach the problem as a non-linear unconstrained minimisation problem on the product manifold of the Special Euclidean Group ($SE_3$). The restriction of the domain of optimisation to the $SE_3$ product manifold not only implies that each intermediate solution is a plausible object motion, but also ensures better intrinsic stability for the minimisation algorithm. We compare our method with existing state of art, and show that our algorithm exhibits superior performance.
Arterial Pulse Rate Variability Analysis for Diagnoses
(Aniruddha Joshi , Sharat Chandran and V. K. Jayaraman and B. D. Kulkarni)
accepted at International Conference on Pattern Recognition , 2008
From the Ayurvedic practitioners point of view, the cycle-to-cycle variations are sometimes more important than the average values. Human pulse rate is affected by a variety of physiological parameters and other important factors including age, sleepwake cycle, disease present, and gender. Peak-to-peak distance varies and the collection of such consecutive intervals to form arterial pulse intervals (API) time series. We introduced PRV analysis on the arterial pulse intervals by computing several time-domain (e.g. SDAPP, PP50 count), frequency-domain (e.g. power, LF/HF), and nonlinear measures (e.g. SD1, SD1/SD2), which show variations with respect to age, and the presence and absence of disorders.
Multifractality In Arterial Pulse
(Aniruddha Joshi , Sharat Chandran and V. K. Jayaraman and B. D. Kulkarni)
accepted at International Conference on Pattern Recognition , 2008
Extensive research has been done to show that heartbeats are composed of the interaction of many physiological components operating on different time scales, with nonlinear and self-regulating nature. We showed the presence of scaling (self-similarity) in inhomogeneous, nonstationary pulse beats using the detrended fluctuation analysis (DFA) through a linear relationship on a log-log graph. These fractal structures were then further established by self-affine cascades of beat-tobeat fluctuations revealed by wavelet decomposition at different time scales. Finally, We showed that our multifractal spectrums vary for pulses from three age-groups and two disorders}
Riemannian Manifold Optimisation for Non-rigid Structure from Motion
(Appu Shaji and Sharat Chandran) accepted at NORDIA, CVPR workshop
This paper address the problem of automatically extracting the 3D configurations of deformable objects from 2D features. Our focus in this work is to build on the observation that the subspace spanned by the motion parameters is a subset of a smooth manifold, and therefore we hunt for the solution in this space, rather than use heuristics (as previously attempted earlier). We succeed in this by attaching a canonical Riemannian metric, and using a variant of the non-rigid factorisation algorithm for Structure from Motion. We qualitatively and quantitatively show that our algorithm produces better results when compared to the state of art.
Fast Color-Space decomposition based Environment Matting
(Biswarup Choudhury and Deepali Singla) accepted at i3D 2008, Redwood City, USA
In the literature, environment matting (EM) refers to the complex process of discovering how light in an environment interacts with an object; notably, it may transfer through a transparent object, and undergo scattering. Modeling the 3D geometry, and the index of refraction, of non-uniformly optically active substances is intractable; therefore image-based frameworks are useful. The most convincing techniques use a large number of (monochrome, or two-tone) probing images to extract the matte. In this paper, we provide an efficient EM technique, for purely refractive/reflective objects, which uses multiple colors as cues, and use a holistic color cube as the environment (instead of repeatedly solving the problem for five sidedrops and one backdrop.)

Poster
Presentation
Videos
Fast, Parallel, GPU-based Construction of Space Filling Curves and Octrees
(Rhushabh Goradia and Prekshu Ajmera) accepted at i3D 2008, Redwood City, USA
Space Filling Curves (SFC) are particularly useful in linearization of data living in two and three dimensional spaces and have been used in a number of applications in scientific computing, and visualization. Interestingly, octrees, another versatile data structure in computer graphics, can be viewed as multiple SFCs at varying resolutions, albeit with parent-child relationship. In this paper we provide a parallel implementation of SFCs and octrees on GPUs that rely on algorithms designed to minimize or eliminate communications.

Poster
Presentation
 
start.txt · Last modified: 2011/05/27 16:30 by sladha
 
Except where otherwise noted, content on this wiki is licensed under the following license:Public Domain
Recent changes RSS feed Donate Powered by PHP Valid XHTML 1.0 Valid CSS Debian Driven by DokuWiki