Andy Chow

Automated Shape Matching

An interdisciplinary research collaboration with CRANE (Computational Research on the Ancient Near East). An automated potsherd matching algorithm was developed for the Ceramic Database using machine learning techniques.

Real-Time Volume Renderer

An interdisciplinary research collaboration with the Biomedical Physics group at UTM, headed by Prof. Virginijus Barzda. A real-time multichannel volume renderer was implemented on the TeraRecon VolumePro 1000 hardware platform, for visualizing data produced by multimodal nonlinear optical (NLO) laser-scanning microscopes.

Wavelets on the 3D Ball

3D SOHO [1] is the first Haar wavelet basis on the three-dimensional ball that is both orthogonal and symmetric. These theoretical properties allow for a fast wavelet transform, optimal approximation, and perfect reconstruction.

1. Andy Chow. Orthogonal and Symmetric Haar Wavelets on the Three-Dimensional Ball. Unpublished Master's thesis, University of Toronto, Toronto, Ontario, Canada, 2010. (PDF, 3.5MB)

Handwriting Recognition

A multi-layer backpropagation neural network for recognizing handwritten digits.

Depiction of Surfaces by 3D Curve Networks

A research experiment to study the accuracy and precision of surface depictions by 3D curve networks. Participants were asked to orient gauges according to their perceived surface normal. Our findings contribute to the understanding of 3D curve sketching interfaces, such as those found in ILoveSketch [1] and 3D Scaffolds [2].

1. Seok-Hyung Bae, Ravin Balakrishnan, Karan Singh. ILoveSketch: As-natural-as-possible Sketching System for Creating 3D Curve Models. Proceedings of the 21st annual ACM symposium on User interface software and technology, 151-160, 2008.
2. Ryan Schmidt, Azam Khan, Karan Singh, Gord Kurtenbach. Analytic Drawing of 3D Scaffolds ACM Transactions on Graphics, 28(5):149-158, 2009.

Image Abstraction

An implementation of real-time image abstraction [1], for the automatic generation of stylized comics from photographs.

1. Holger Winnemöller, Sven C. Olsen, Bruce Gooch. Real-Time Video Abstraction. ACM Transactions on Graphics, 25(3):1221-1226, 2006.

Figure 8 Gait Editor

A novel approach for editing bipedal gaits in Autodesk Maya. During a gait cycle, the pelvis follows a sinusoidal curve in 3D space. A "figure 8" curve (like the infinity symbol) is formed by projecting the sinusoidal curve onto a plane that is perpendicular to the direction of travel. Subsequently, a 3D gait can be edited in 2D by modifying its figure 8 curve. The same technique can also stylize movements of the hips, knees, and other parts of the body.

Learning to Rank

A new probabilistic lambda gradient for LambdaRank [1] was created. Its effectiveness in learning the Normalized Discounted Cumulative Gain (NDCG) target cost function was determined empirically, and compared against that of RankNet, ListNet, and LambdaRank.

1. Christopher Burges, Robert Ragno, Quoc Viet Le. Learning to Rank with Nonsmooth Cost Functions. Advances in Neural Information Processing Systems 19, 193-200, 2007.

Impressionist Rendering

An NPR application for rendering impressionist paintings via abstract image filters [1], with user-specified brush shape, size, and stroke orientations.

1. Paul Haeberli. Paint by Numbers: Abstract Image Representations. Proceedings of the 17th Annual Conference on Computer Graphics and Interactive Techniques, 207-214, 1990.

Textured Paint Strokes

An NPR application for simulating the physical appearance of paint strokes under gallery lights [1].

1. Aaron Hertzmann. Fast Paint Texture. Proceedings of the 2nd International Symposium on Non-Photorealistic Animation and Rendering, 99-105, 2002.

Non-Photorealistic Rendering

An interactive 3D mesh viewer, for showing suggestive contours, edge contours, and smooth contours. Additional features include toon shading, and varying stroke thickness determined by curvature.

The God of Maya

A short animated skit that was created using Autodesk Maya. The video was produced for a graduate course in Character Animation, taught by one of the creators of Maya, Prof. Karan Singh.

Exaggerated Shading

An interactive 3D viewer for exaggerated shading [1] and other styles of non-photorealistic renderings.

1. Szymon Rusinkiewicz, Michael Burns, Doug DeCarlo. Exaggerated Shading for Depicting Shape and Detail. ACM Transactions on Graphics, 25(3):1199-1205, 2006.

SIMBICON

An implementation of SIMBICON (Simple Biped Locomotion Control) [1], for a graduate course in Physics-Based Character Animation with Prof. Aaron Hertzmann. The 2D walking biped has eight degrees of freedom, and physics simulated by the Open Dynamics Engine (ODE).

1. KangKang Yin, Kevin Loken, Michiel van de Panne. SIMBICON: Simple Biped Locomotion Control. ACM Transactions on Graphics, 26(3), 2007.

Intelligent Scissors

An implementation of the Intelligent Scissors [1] tool for semi-automatic image segmentation. The program uses edge detection and user-specified points to determine a segmentation boundary. The user can alter the points to modify the segmentation boundary in real-time.

1. Eric N. Mortensen, William A. Barrett. Intelligent Scissors for Image Composition. Proceedings of the 22nd Annual Conference on Computer Graphics and Interactive Techniques, 191-198, 1995.

Image Morphing

An implementation of feature-based 2D image morphing [1]. The user provides a set of line mappings from a source image to a destination image. Pixel transformations are computed based on the distance-weighted transformation of each line pair.

1. Thaddeus Beier, Shawn Neely. Feature-Based Image Metamorphosis. Proceedings of the 19th Annual Conference on Computer Graphics and Interactive Techniques, 35-42, 1992.

Haar Wavelet Tiling

Multiresolution analysis is performed on a source image via Haar wavelet transform. A new image is formed by using tiles of various colors and sizes, selected based on the details in the transformed source image. The user can specify the resolution, tile texture and range of tile sizes.

Global Illumination Renderer

A ray-tracer implemented for a graduate course in Computer Graphics, taught by Prof. Aaron Hertzmann. Illumination effects include soft shadows, perfect reflections, texture mapping, and Phong shading (diffuse and specular illumination).