Linear Object Classes and Image Synthesis from a Single Example Image

The need to generate new views of a 3D object from a single real image arises in several fields, including graphics and object recognition. While the traditional approach relies on the use of 3D models, we have recently introduced techniques that are applicable under restricted conditions but simpler. The approach exploits image transformations that are specific to the relevant object class and learnable from example views of other "prototypical" objects of the same class. In this paper, we introduce such a new technique by extending the notion of linear class first proposed by Poggio and Vetter. For linear object classes it is shown that linear transformations can be learned exactly from a basis set of 2D prototypical views. We demonstrate the approach on artificial objects and then show preliminary evidence that the technique can effectively "rotate" high- resolution face images from a single 2D view

The characteristic cohomology class of a triangulated category

This is the final version of a series of papers uploaded in May 25, 2005. We have splitted the long last paper of the previous version in two parts to make it easier to understand. The results are essentially the same, although the presentation has changed substantially. The first three papers have not changed. This is a collection of five papers on the foundation of triangulated categories in the context of groupoid-enriched categories, termed track categories, and characteristic cohomology classes. As a main result it is shown that given an additive category A with a translation functor t: A --> A and a class V in translation cohomology H^3(A,t) then two simple properties of V imply that (A,t) is a triangulated category. The cohomology class V yields an equivalence class (B,[s]) where B is a track category with homotopy category A and [s] is the homotopy class of a pseudofunctor s: B --> B inducing t. The two properties of V correspond to natural axioms on B and s which again imply that (A,t) is a triangulated category. The five papers of this volume depend on each other by cross references, but each paper can be read independently of the others so that the reader is free to choose one of the papers to start. Each paper has its own abstract, introduction and literature.Comment: 166 pages, some diagrams do not appear correctly in the DVI fil

Juice: An SVG Rendering Peer for Java Swing

SVG—a W3C XML standard—is a relatively new language for describing low-level vector drawings. Due to its cross-platform capabilities and support for events, SVG may potentially be used in interactive GUIs/graphical front-ends. However, a complete and full-featured widget set for SVG does not exist at the time of this writing. I have researched and implemented a framework which retargets a complete and mature raster- based widget library—the JFC Swing GUI library—into a vector-based display substrate: SVG. My framework provides SVG with a full-featured widget set, as well as augmenting Swing’s platform coverage. Furthermore, by using bytecode instrumentation techniques, my Swing to SVG bridging framework is transparent to the developers— allowing them to implement their user interfaces in pure Swing

Subjects, Models, Languages, Transformations

Discussions about model-driven approaches tend to be hampered by terminological confusion. This is at least partially caused by a lack of formal precision in defining the basic concepts, including that of "model" and "thing being modelled" - which we call subject in this paper. We propose a minimal criterion that a model should fulfill: essentially, it should come equipped with a clear and unambiguous membership test; in other words, a notion of which subjects it models. We then go on to discuss a certain class of models of models that we call languages, which apart from defining their own membership test also determine membership of their members. Finally, we introduce transformations on each of these layers: a subject transformation is essentially a pair of subjects, a model transformation is both a pair of models and a model of pairs (namely, subject transformations), and a language transformation is both a pair of languages and a language of model transformations. We argue that our framework has the benefits of formal precision (there can be no doubt about whether something satifies our criteria for being a model, a language or a transformation) and minimality (it is hard to imagine a case of modelling or transformation not having the characterstics that we propose)

Empowering Collections with Swarm Behavior

Often, when modelling a system there are properties and operations that are related to a group of objects rather than to a single object. In this paper we extend Java with Swarm Behavior, a new composition operator that associates behavior with a collection of instances. The lookup resolution of swarm behavior is based on the element type of a collection and is thus orthogonal to the collection hierarchy

Aspect-Oriented Programming

Aspect-oriented programming is a promising idea that can improve the quality of software by reduce the problem of code tangling and improving the separation of concerns. At ECOOP'97, the first AOP workshop brought together a number of researchers interested in aspect-orientation. At ECOOP'98, during the second AOP workshop the participants reported on progress in some research topics and raised more issues that were further discussed. \ud \ud This year, the ideas and concepts of AOP have been spread and adopted more widely, and, accordingly, the workshop received many submissions covering areas from design and application of aspects to design and implementation of aspect languages