Irfan Essa's Academic Activities

Vivek Kwatra, Arno Schödl, Irfan Essa, Greg Turk, Aaron Bobick (2003), “Graphcut textures: image and video synthesis using graph cuts” In ACM Transactions on Graphics (TOG), Volume 22 , Issue 3, Proceedings of ACM SIGGRAPH 2003, Pages: 277 – 286, July 2003, ISSN:0730-0301. (DOI|Paper| SIGGRAPH Video (160 MB, 50 MB) | Video Results 87 MB | Project Site)

ABSTRACT

In this paper we introduce a new algorithm for image and video texture synthesis. In our approach, patch regions from a sample image or video are transformed and copied to the output and then stitched together along optimal seams to generate a new (and typically larger) output. In contrast to other techniques, the size of the patch is not chosen a-priori, but instead a graph cut technique is used to determine the optimal patch region for any given offset between the input and output texture. Unlike dynamic programming, our graph cut technique for seam optimization is applicable in any dimension. We specifically explore it in 2D and 3D to perform video texture synthesis in addition to regular image synthesis. We present approximative offset search techniques that work well in conjunction with the presented patch size optimization. We show results for synthesizing regular, random, and natural images and videos. We also demonstrate how this method can be used to interactively merge different images to generate new scenes.

Arno Schödl and Irfan Essa (2002), “Controlled animation of video sprites” Proceedings of the 2002 ACM SIGGRAPH/Eurographics symposium on Computer animation. ACM Press, Pages: 121 – 127 July 2002, San Antonio TX, ISBN:1-58113-573-4.  (DOI|PDF|WebSite)

ABSTRACT

We introduce a new optimization algorithm for video sprites to animate realistic-looking characters. Video sprites are animations created by rearranging recorded video frames of a moving object. Our new technique to find good frame arrangements is based on repeated partial replacements of the sequence. It allows the user to specify animations using a flexible cost function. We also show a fast technique to compute video sprite transitions and a simple algorithm to correct for perspective effects of the input footage. We use our techniques to create character animations of animals, which are difficult both to train in the real world and to animate as 3D models.

Video textures

Abstract

This paper introduces a new type of medium, called a video texture, which has qualities somewhere between those of a photograph and a video. A video texture provides a continuous infinitely varying stream of images. While the individual frames of a video texture may be repeated from time to time, the video sequence as a whole is never repeated exactly. Video textures can be used in place of digital photos to infuse a static image with dynamic qualities and explicit actions. We present techniques for analyzing a video clip to extract its structure, and for synthesizing a new, similar looking video of arbitrary length. We combine video textures with view morphing techniques to obtain 3D video textures. We also introduce video-based animation, in which the synthesis of video textures can be guided by a user through high-level interactive controls. Applications of video textures and their extensions include the display of dynamic scenes on web pages, the creation of dynamic backdrops for special effects and games, and the interactive control of video-based animation.

• Schödl, A., Szeliski, R., Salesin, D. H., and Essa, I. 2000. Video textures. In Proceedings of the 27th Annual Conference on Computer Graphics and interactive Techniques International Conference on Computer Graphics and Interactive Techniques. ACM Press/Addison-Wesley Publishing Co., New York, NY, 489-498. [DOI][PDF]
• Project WebPage
• Presentation Slides
• SIGGRAPH 2000 Video