Signal Classification and Synthesis using Scattering Operators

Since my master thesis I am studying some aspects related to terrain modeling. In the last year I began to study some aspects related to signal classification to understand this process and try to use some information in the synthesis of stationary processes.

I am using the scattering operators to decompose the signal and use this representation to signal classification. It is a good representation for stationary signals, such as terrain and texturing. After understanding the classification problem, I intend to use this representation on terrain and texture synthesis.

The stationary operator theory was proposed by Stephane Mallat et. al. More information can be found in the page of the project.

As part of this research I wrote a technical report, advised by Luiz Velho. Besides this, I presented a talk on IMPA's seminar (both materials in Portuguese).

Terrain Modeling and Visualization

The theme of my master thesis is Terrain Modeling and Visualization. In particular, I have studied how to specify terrain from sketches.

Terrain modeling is an inherent problem in applications of various categories, among which we mention: geographic applications, combat flight simulations, creation of environments for movies, animations and games, etc. To model a terrain it is necessary to define how the processes of specification, representation and synthesis will be done.

Our approach to specify terrain is using sketches. The representation uses height maps; and the synthesis is done using a view-dependent adapted mesh, shading and colorize function.

The first results are the project of 3D Graphics Systems Course.

Sketch-Based Modeling

Geometric Modeling is a widely studied area in computer graphics and methods from constructing 3D models with intuitive interfaces are a topic that has been attracting the interest of many researches. In contrast to the complicated interfaces of modeling software, created using the WIMP paradigm (Window, Icon, Menu, Pointer), several studies have shown applications with interfaces based on gestures, which are simpler and more natural. In this scenario, the area of Sketch-Based Interfaces and Modeling (SBIM) emerged.

Sketch is a very efficient tool to convey the essence of an object with few strokes, because humans have the ability of inferring 3D models from 2D drawings. However, associating a sketch to a 3D model is not a computationally trivial task.

As result of our research on SBIM, we develop a technical report refering to the studies of state of art in this area; we made a conceptualization of the area, highlighting opportunities, challenges and trends in SBIM; and developing prototypes for proof some studied concepts. We developed a toolkit called SBIM-TK, and some SBIM applications, as examples. Finally, we will present, on SIBGRAPI' 10, a course called: A sketch on Sketch-based Interface and Modeling.