Tommer Leyvand

 

 

I have graduated with M.Sc. in Computer Science from Tel-Aviv University under the guidance of Prof. Daniel Cohen-Or.
My main research interests include Computer Graphics and Vision.

I currently work for Microsoft Corporation (Redmond) on Project Natal and continue doing research on my spare time.

 

Curriculum Vitae (on LinkedIn)

 


 

Publications

Data-Driven Enhancement of Facial Attractiveness
Tommer Leyvand, Daniel Cohen-Or, Gideon Dror and Dani Lischinski
ACM SIGGRAPH 2008
Pages
In this work we focus on the challenging problem of enhancing the aesthetic appeal (or the attractiveness) of human faces in frontal photographs (portraits), while maintaining close similarity with the original. The key component in our approach is an automatic facial attractiveness
engine trained on datasets of faces with accompanying facial attractiveness ratings collected from groups of human raters. More ...

Digital Face Beautification SIGGRAPH 2006, Technical Sketch page (here)

Color Harmonization
Daniel Cohen-Or, Olga Sorkine, Ran Gal, Tommer Leyvand and Ying-Qing Xu
ACM SIGGRAPH 2006
 
Harmonic colors are sets of colors that are aesthetically pleasing in terms of human visual perception. In this paper, we present a method that enhances the harmony among the colors of a given photograph or of a general image, while remaining faithful, as much as possible, to the original colors. Given a color image, our method finds the best harmonic scheme for the image colors. It then allows a graceful shifting of hue values so as to fit the harmonic scheme while considering spatial coherence among colors of neighboring pixels using an optimization technique. The results demonstrate that our method is capable of automatically enhancing the color "look-and-feel" of an ordinary image. More ...

Interactive Object Segmentation in Video by Fitting Splines to Graph Cuts
Iddo Drori, Tommer Leyvand, Daniel Cohen-Or and Hezy Yeshurun
ACM SIGGRAPH 2004 Posters Session
Object segmentation in image sequences is one of the fundamental problems in computer vision and graphics. This problem is usually addressed either by discrete representations which are currently manifested by graph partitioning techniques, or by continuous methods typically referred to as active contours. In this work we take a unified approach by fitting splines to graph cuts. The strengths of this approach stem from the dual discrete and continuous representations and from allowing the user to refine the result of the cut by fitting a new spline to it and modifying its points. More ...

Video Operations in the Gradient Domain
Iddo Drori, Tommer Leyvand, Shachar Fleishman, Daniel Cohen-Or and Hezy Yeshurun
Technical Report, May 2004
Fusion of image sequences is a fundamental operation in numerous video applications and usually
consists of segmentation, matting and compositing. We present a unified framework for performing
these operations on video in the gradient domain. Our approach consists of 3D graph cut computation followed by reconstruction of a new 3D vector field by solving the Poisson equation. We demonstrate the applicability of smooth video transitions by fusing pairs for video mosaics, video folding, and video texture synthesis, and demonstrate the applicability of sharp video transitions by video segmentation, video trimap extraction and 3D compositing into a new sequence. Our results demonstrate that our method maintains coherence of the video matte and composite, and avoids temporal artifacts. More ...

Ray Space Factorization for From-Region Visibility
Tommer Leyvand, Olga Sorkine and Daniel Cohen-Or
ACM SIGGRAPH 2003
This paper present a conservative occlusion culling method based on factorizing the 4D from-region visibility problem into horizontal and vertical components. The visibility of the two components is solved asymmetrically: the horizontal component is based on a parameterization of the ray space, and the visibility of the vertical component is solved by incrementally merging umbrae. The technique is designed so that the horizontal and vertical operations can be efficiently realized together by modern graphics hardware. More ...

 

Projects
CityGen - Procedural Urban Model Generator

CityGen is a procedural 3D model generator application aimed for generating random urban models. These models are generated from an XML construction file using several simple operations and random inputs. Developed as a side project from my "Ray-Space Factorization for From-Region Visibility" paper. More ...

 

 07/07/2005, V0.9 of CityGen released (download here)
 

 

Online source-code:


Advanced Topic in Computer Graphics / Spring 2004