IMPA Tech students present project at CBM thematic session

IMPA Tech undergraduates are at the 35th Brazilian Mathematical Colloquium as audience and also as speakers. Pedro Henrique Reis and Marcos Abílio, from class 2024, shared their experiences during the IMPA Summer School, in the thematic session “Reproducing Results in Computer Graphics”, coordinated by Visgraf (IMPA’s Computer Graphics Laboratory). Professor Asla Sá also took part in the session.

The students presented how to tackle the problems that exist in computer graphics while adapting algorithms from classic papers. As well as explaining how these algorithms work, they talked about the decision-making process for adapting papers into today’s programming languages. To do this, basic techniques such as reading images and applying monochrome effects were incorporated into classic digital halftone algorithms. Mathematical theorems such as space coverage curves were also shown.

“Participating in the Colloquium was a unique and very special experience for me. We had the opportunity to present the Computer Graphics work that I and some other IMPA Tech students had developed during the summer. It was a valuable experience to show IMPA Tech’s presence, show what we’ve learned and exchange knowledge. We presented to interested and engaged students and researchers, making it a very rewarding experience. I didn’t expect an opportunity like this so soon, so it motivates me even more to keep learning,” said Reis.

 

The idea was to replicate two important papers in the field of Computer Graphics and make them publicly accessible. One of them was published in 1991 by researchers Luiz Velho (IMPA) and Jonas de Miranda Gomes and explores the digital halftone.

The other is a paper by Voronoi Stippling, which works on dotting with Voronoi. This second project led to the creation of a website where users can upload a file and can customize the number of dots and the number of interactions for the revitalization of articles.

“We ended up taking a lot of inspiration from the Summer School, as we created notions of pre- and post-processing image manipulation, such as formatting PNG and JPEG images. We also learned about converting images to the matrix to be able to do this processing and ways of developing and reapplying the algorithms. In the case of this project, we took these classic algorithms and reapplied them in Python and delivered them on websites and libraries for everyone to use,” explained Abílio.

Fernanda Domingues, an undergraduate student at UENF (Universidade Estadual do Norte Fluminense), attended the Computer Graphics thematic session for the first time at IMPA to learn about a subject she hadn’t had any contact with at university. “I’m still not familiar with some of the terms, but it’s really cool to see them applied here. I thought the boys’ work and the results of the mini-course were very good. It’s great to see what IMPA is doing. So I’m very pleased, very happy for them,” she said.

Asla Sá gives lecture “Data Visualization: a theoretical dive and a proposal for progress”

 

Undergraduate professor Asla Sá also took part in the thematic session “Vision and Computer Graphics” on Tuesday (29). The professor explored new data visualization grammars for generating graphics and presented a proposed experimental implementation, the Vizagrams. The model’s main contribution is to increase the expressiveness of grammars.

“In the grammar of graphs, we start from a unit, which is the graph, and we have all the things that are underneath the graph. What happens? We don’t manipulate this graph, it’s the root of the matter, it can’t be manipulated. In our case, what we do here is recursion. We take this graph, call it a mark, and the graph itself is a mark. By calling the graphic a mark, you can manipulate it, rotate it and do everything you do with any mark. So we’ll have your marks and your mark trees,” explained Asla.

The result of the doctoral work of student Davi Salles, who was supervised by Asla, the lecture included in-depth historical and theoretical research into the proposals for formalizing the assembly of statistical graphs in the academic world. Among them, Wilkinson’s work on the Grammar of Graphics (GoG), which underpinned tools such as ggplot2 and Vega-Lite.

The result was an investigation into new ways of visualizing data that tend towards greater expressiveness. The research also conceived of data visualization as diagrams, unifying the concepts of diagrams and visualization in a single theoretical model.

Jonas Santos Siqueira is a master’s student at the Brazilian Institute of Economics of the Getúlio Vargas Foundation (IBRE/FGV) and USP (University of São Paulo) and is visiting Rio de Janeiro for the first time to take part in the 35th CBM. “I’ve never been to a Mathematics Colloquium of this size before, this is my first academic event too. What caught my attention most in this thematic session was the presentation on visualization methods. I was intrigued because I didn’t know there was so much theory behind the development of a bar graph. It’s also nice to know that it all started with a proposal for a doctoral work, the author had a little problem, went there and solved it. It gave me some inspiration and also a new perspective on what I can do now in future projects, even more so for my dissertation,” said Siqueira.

Read also: ‘CBM is an example of what IMPA does best’, says Marcelo Viana