Yale

 

Computer Graphics
                                                  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Xuejin Chen (陈雪锦)

 

Postdoctoral Associate

 

51 Prospect St. AKW 510, New Haven, CT 06511, United States

 

Email: xuejin DOT chen AT yale DOT edu

Office Tel: (+1) 203-432-1228

 

 Resume         Research         Publications

 

Research Interests

-         Sketch based modeling  

-         Image Based Rendering

-         Shape perception

 

 

 

 

 

 

 

 

 

Education

I obtained Ph.D. and B.S in Department of Electronic Science and Technology in University of Science and Technology of China (USTC) in 2008 and 2003. My Ph.D. supervisor is Prof. Heung-Yeung Shum. I had been taking internship in Visual Computing Group in Microsoft Research Asia (MSRA) since July 2004 to 2008. My mentors were Dr. Ying-Qing Xu and Sing Bing Kang. Now I am working with Prof. Julie Dorsey on sketching related projects.

 

 

 

 

 

Research Projects

 

 

 Printed Patterns for Enhanced Shape Perception on Papercraft Models [PDF]

 

Su Xue, Xuejin Chen, Julie Dorsey, Holly Rushmeier.

Computer Graphics Forum, (Proceedings of Eurographics 2010), Vol. 29, Issue 2.

 

 

Papercraft models can serve as inexpensive prototypes in shape design applications. However, in making the models some geometric detail is necessarily lost, and artificial creases may be visible, thereby limiting the utility of these models. To compensate for these practical limitations, we introduce the use of printed patterns on papercraft models to enhance the perception of the shape they are intended to represent. We propose pattern generation schemes that modulate the sizes, directions, and densities of glyphs of patterns based on geometric attributes. We present a psychophysical experiment designed to explore the effect that printed patterns have on the perception of the papercraft model shapes. We find that models with printed patterns are perceived to represent the intended shape more accurately, and, further, that the type of printed pattern has an impact on the perceived shape.

 
 

 

 

 Sketch-Based Tree Modeling Using Markov Random Field [PDF][Video(divx)]

 

Xuejin Chen, Boris Nerburt, Ying-Qing Xu, Oliver Deussen, Sing Bing Kang.

ACM Siggraph Asia and Transaction on Graphics, Vol. 27, No. 5, 2008.

 


In this paper, we presented an easy-to-use system for converting a 2D free-hand sketch of a tree to full 3D model that is both complex and realistic-looking. Our system does this by probabilistic optimization based on parameters obtained from a database of tree models. Branch interaction is modeled by a Markov random field, subject to the constraint of 3D projection to sketch. Our system then uses the notion of self-similarity to add new branches before finally populating all branches with leaves of the user's choice. A variety of natural-looking tree models can be generated from freehand sketches with only a few strokes.

 

 

 

 

 

 

 

 

 

 

 

 

 Sketching Reality: Realistic Interpretation of Architectural Designs  [PDF][Video(divx)]

 

Xuejin Chen, Sing Bing Kang, Ying-Qing Xu, Julie Dorsey, Heung-Yeung Shum,

ACM Transaction on Graphics,Vol. 27, No. 2, April 2008.

We presented a novel flexible system of converting the user’s freehand sketching to realistic rendering for complicated architecture design. The primitive geometries, detailed geometries and textures are interpreted from freehand sketches. Our system allows the user to easily draw sketch, modify the geometry model, texture and view the realistic rendering of the complex architecture models

 

 

 

 

 

 

 Retargeting Vector Animation for Small Displays[PDF]

 

Vidya Stelur, Xuejin Chen, Ying-Qing Xu, Bruce Gooch,

Proceedings of the 4th international conference on Mobile and Ubituitous Multimedia, ACM Press, 2005, Vol. 154

 

I proposed the algorithm of retargeting vector animation when it is resized, especially for small displays. The recognizability of the interaction between key objects is preserved by analyzing the perceptual complexity of objects. My work includes implementing the parser of XML file, designing and implementing the object simplification and exaggeration based on perceptual complexity.

 

 

 

 

 

 

 Poisson Video Editing

I implemented the video editing algorithm by solving Poisson equation based on incomplete Cholesky conjugate gradient method for large sparse matrix. Different guide vector fields from the gradient of the source and target video are computed to produce different mergence effects of the videos.

 

 

 

 

 

 

Publications

  • Su Xue, Xuejin Chen, Julie Dorsey, Holly Rushmeier, Printed Patterns for Enhances Shape Perception on Papercraft models, Computer Graphics Forum, (Proceedings of Eurographics 2010), Vol. 29, Issue 2. [PDF]
  • Xuejin Chen, Boris Nerburt, Ying-Qing Xu, Oliver Deussen, Sing Bing Kang, Sketch-based tree modeling using Markov random field, ACM Siggraph Asia and Transaction on Graphics, Vol. 27, No. 5, 2008. [PDF]
  • Xuejin Chen, Sing Bing Kang, Ying-Qing Xu, Julie Dorsey, Heung-Yeung Shum, Sketching Reality: realistic interpretation of architectural design, ACM Transaction on Graphics,Vol. 27, No. 2, April 2008. [PDF]
  • Vidya Stelur, Xuejin Chen, Ying-Qing Xu, Bruce Gooch, Retargeting vector animation for small displays, Proceedings of the 4th international conference on Mobile and Ubituitous Multimedia, ACM Press, 2005, Vol. 154, pages 69-77. [PDF]