The present volume constitutes the proceedings of the Technical Posters of the XXI Brazilian
Symposium on Computer Graphics and Image Processing (SIBGRAPI 2008), held on October 12-
15, in Campo Grande, MS, one of the most beautiful cities in Brazil.
This year, 19 papers were accepted out of a total of 29 submissions, which led to an acceptance
rate of 65.52%. Each paper was evaluated by three referees. Based on their technical reviews, we
selected the accepted articles for exhibition in the SIBGRAPI 2008 Technical Poster Session.
We are very thankful to the authors that chose SIBGRAPI as the place to present their work. Credit
also goes to the seventeen Program Committee members, who kindly donated their time and
experience to evaluate the submissions. They were chosen based on their extensive expertise and
their reputation for good and fair judgement. We also thank the local organization committee, the
SIBGRAPI Co-Chairs Marcelo Walter and Claudio Jung, the twenty-seven reviewers for their
invaluable collaboration and informative reviews, and all the authors who submitted papers, whose
contributions were fundamental to the quality of the technical program. Finally, we would like to
thank the University of Fortaleza (UNIFOR) and Federal University of Uberlandia.
We wish all the participants a pleasant and learning journey at SIBGRAPI 2008 and, particularly,
during the Oral Presentations of the Technical Posters.
Campo Grande, MS, Brazil, October 12-15, 2008.
Maria Andréia Formico Rodrigues and Célia Zorzo Barcelos
(Technical Posters SIBGRAPI 2008 Co-Chairs)
DICOM Server Applied to Medical Image Processing
Luis Sebastián Barberis,
Juan Pablo Graffigna Vaggione,
María Eugenia Gómez Marrello, and
(Universidad Nacional de San Juan)
(pp 1 - 2).
This work describes the design and implementation of
a DICOM server that manages medical image studies for
their further processing. It is based on connectivity
specifications of a massive clinic standard, and has the
capacity to manage studies and to run different
processing algorithms, according to a decision making
system by means of databases. The design provides great
flexibility in terms of configuration and operations
assignment, and permits compatibility with DICOM
images transmission systems. The goal of the
development is to apply automatic algorithms of clinical
image processing carried out by research groups. By
means of this system, it is possible to validate clinically
new algorithms and employ them for the diagnosis and
Watershed Transform based Interactive Image Segmentation Tool
Bruno Klava (USP) and Nina Hirata (USP)
(pp 3 - 4).
Watershed from markers and hierarchical watershed are
approaches suitable for interactive image segmentation: in
the former, the user can edit markers to control the segmentation
result; in the latter, the user can select an image
partition from a nested set of partitions. We propose an
interactive image segmentation tool that allows transition
from one approach to other and thus the combination of the
strengths of both.
Marvin: A Tool for Image Processing Algorithm Development
Gabriel Archanjo, Fabio Andrijauskas, and Danilo Rosetto Muñoz
(pp 5 - 6).
This work presents, Marvin, tool for image
processing algorithm development. This tool is
composed by a framework and an image manipulation
program that supports extensibility through plug-ins.
The framework, used to develop the plug-ins, provides
features for image manipulation, algorithm analysis
and integration with the base application. Marvin is
suitable for image processing algorithm development
and prototyping and for education purpose.
Color Gradient Map-Oriented Anisotropic Diffusion Filtering
Leandro Coser (UFSC), Antonio Sobieranski (UFSC), Adiel Mittmann (UFSC),
Eros Comunello (UNIVALI), and Aldo Wangenheim (UFSC)
(pp 7 - 8).
Anisotropic diffusion filtering is a well-established technique
for image enhancement that smooths images without
destroying edge information. However, when many filtering
iterations are applied, edges gradually fade away and are
ultimately smoothed by the process. We propose the adoption
of a color gradient map to guide the smoothing so that
clearly-defined edges are preserved even after many iterations.
Preliminary experiments show good results when
compared with the regular anisotropic diffusion filter.
OCR4JkanjiCards: Exploring Japanese Character Recognition
Oswaldo Bassani Neto (USP), Celso Kurashima (UFABC), and Marcelo Z. do Nascimento (UFABC)
(pp 9 - 10).
The OCR4JkanjiCards system is presented in this
work, as a proposal for taking photos of Japanese
characters using a smartphone and have them
automatically recognized within a digital Japanese
dictionary. Image processing techniques and neural
network strategies are necessary, as well as the
exploration of several programming tools.
Fusion of Infrared and Visible Spectra Face Recognition Methods
Giovani Chiachia (USP) and Aparecido Marana (UNESP)
(pp 11 - 12).
In general, face recognition systems are based on
visible spectrum images and, in order to have good
performance, they need to work in light-controlled
environments. However, the performance of such
systems decrease significantly when illumination
changes. On other hand, Long-Wave Infrared (LWIR)
face imagery is insensitive to illumination changes and
gives the temperature pattern from the face to be
recognized. The purpose of this work is to assess the
performance of the fusion of well-known statistical
visible and LWIR-based methods for face recognition.
SAR Image Compression Using Bounded Variation Component Analysis
Regis Marques, Daniel S. Ferreira, Fátima Medeiros, Janaina Cruz, and Maria Duarte
(pp 13 - 14).
This paper proposes a scheme to compress SAR (Synthetic
Aperture Radar) images aiming for preserving fine
details such as bright targets. This scheme consists in decomposing
a SAR image into bounded variation (BV) and
oscillating components. The adaptive compression scheme
is a modified version of the well known SPIHT method
named in this paper as MSPIHT. The experiments using
real SAR images were compared with JPEG2000 and the
conventional SPIHT. The assessment results indicated a superior
performance of method in preserving fine details.
A Fourier Transform-based Method to Fusion IKONOS Data
Juliana Denipote (USP) and Maria Stela V. de Paiva (EESC-USP)
(pp 15 - 16).
The principal objective of image fusion in remote
sensing is to obtain high-resolution multispectral
images that can combine the spectral characteristic of
the low-resolution multispectral bands with the spatial
information of the high-resolution panchromatic band.
A method based on Fourier transform is proposed in
order to obtain good spatial and spectral resolutions
using all bands of IKONOS satellite. Quantitative
measurements were applied to compare the results of
the proposed method with IHS, IHS enhanced by
Fourier transform and wavelet-based methods.
A new Content-Based Image Retrieval Methodology Based on Image Registration
Algorithms Processed in Grid Computing
Marcelo Oliveira (UFAL), Walfredo Cirne (UFCG), José Flávio Júnior (UFCG), and
Paulo de Azevedo-Marques (USP)
(pp 17 - 18).
The Content-Based Image Retrieval (CBIR) has
received great attention in the medical community
because it is capable of retrieving similar images that
have known pathologies. This work proposes a new
methodology based on higher processing provided by
the Grid Computing (GC) technology to achieve the
CBIR using Registration algorithms. We evaluate the
accuracy in retrieving images of the same plane,
weighted and acquisition sequence related to a
reference image. This works uses a heterogeneous
image database and uses two anatomic regions (breast
and head) as reference. The IR procedure uses Mean
Square Metric (MSM) and Cross Correlation (CC).
Both metrics showed a higher efficiency, MSM
obtained 83% (breast) and 94% (head) precision
average, the CC showed 81% (breast) and 98% (head).
The higher computational cost related to the Image
Registration were amortized by the GC, showing a
potential low cost solution for secure data
interchanging and integrating multiple hospitals and
Improving Content-based Image Retrieval by Combining Growing Hierarchical Self
Organizing Map Classifiers for Color, Shape and Texture Features
Saulo de Tarso Rodrigues, Tiago Albuquerque, and Herman Gomes (UFCG)
(pp 19 - 20).
This paper presents the development of a content-based
image retrieval system that combines a set of GHSOM
(Growing Hierarchical Self Organizing Map) classifiers
taking as input color, shape and texture features. Experiments
demonstrated combination scenarios that produced
better accuracy in image classification.
Computer Graphics, Vision and Modeling
Francisco B. Murilo (University of Costa Rica), Douglas N. Guevara (Universidad Nacional de Costa
Rica), Francisco Torres-Rojas (Instituto Tecnológico de Costa Rica), and Alexander R. Gonzalez (University of
(pp 21 - 22).
Subdivision is a method to create smooth surfaces
through a refinable schema of polygonal or triangular
meshes. From a mathematical point of view, this technique
is an application of a second generation wavelet analysis.
At the same time, this analysis is based on the lifting
schema and does not use any frequency criterion to define
scaling functions or wavelets. This simplifies computational
cost. Yet, a frequency analysis applied to a polygonal mesh,
can provide an intuitive method to modify surface characteristics
by creating an analogy to one-dimensional sound
equalization. These foundations can be useful not only as
a surface generation tool, but they are also naturally associated
to finite element techniques and can be applied to a
wide variety of simulation problems.
Efficient Computation of Global Illumination for Image Synthesis
Anamaria Gomide, Danillo Pereira, and Jorge Stolfi (UNICAMP)
(pp 23 - 24).
We are exploring various functional approximation
schemes (such as radial bases and Shepard’s interpolation)
for precomputed radiance transfer (PRT), a finite element
approach for real-time radiosity of complex scenes.
Using Metaprogrammed Functors to Implement Double-Dispatch for Collision Handling
Tiago Nobrega, Diego Carvalho, and Aldo von Wangenheim (UFSC)
(pp 25 - 26).
We provide a strategy to the management of collisions
between multiple objects with different types employing
multiple-dispatch and both Object-Oriented and Generic
Programming concepts. The solution scales well to the
number of object types, with a fixed, constant-time cost to
arrive at the proper interference-detection routine. Additionally,
it helps the application programmer by allowing
them to implement only the functionality required by their
own program, removing the need for common solutions such
as Abstract Base Classes full of pure virtual methods.
A Geometric Bisection Algorithm for Automatic Page Layout
Alexandre Seki, Mauricio Klein, Ricardo Piccoli, Isabel Manssour, and João Oliveira (PUC-RS)
(pp 27 - 28).
Content distribution in a page designed for printing is a
difficult task performed by human editors. There are applications
and tools to help the editor in this task, but it is still a
manual, iteractive process that is made more difficult when
content is distributed in columns, as is the case of newspapers.
This work describes an algorithm to automatically
distribute content in a printable page. Our implementation
tries to use all the page, dividing it among the items to be
placed according to their area.
Enabling Interactive Brain Fiber Tracking with the GPU
Adiel Mittmann, Tiago Nobrega, Eros Comunello, Diego Carvalho, and Aldo von Wangenheim (UFSC)
(pp 29 - 30).
Brain fiber tracking allows a neurosurgeon to find fiber
bundles in any region of the human brain, rendering it a
useful aid to preoperative planning. However, this process
requires a significant amount of computation, which limits
the interactivity of current applications. We show how executing
this process on graphics processing units can significantly
improve the user’s experience by computing the fiber
tracts in real time.
Physically Based Simulation Using Particle Systems
Yalmar Atencio (COPPE/UFRJ) and Claudio Esperança (UFRJ)
(pp 31 - 32).
This work consists of extending the rigid body simulation
method presented by Harada. Firstly, the Newtonian
formulation is replaced by impulse based physics.
Secondly, deformable body simulation is achieved by using
two different approaches: non-zero volume objects are handled
by an adapted meshless shape matching technique,
whereas objects such as cloths and ropes are simulated using
3D Texture Painting of Point Models
José Ricardo M. Viana, Ricardo Marroquim, and Claudio Esperança (UFRJ)
(pp 33 - 34).
We propose a technique for painting 3D models based
on a rendered image of the model and a 2D map of normal
vectors. Texture generation and coordinate mapping is then
produced on-the-fly, making it possible to paint in broad
strokes or in small detail. The minimalistic requirements
of this technique make it suitable for painting both regular
meshes and point-based models.
Level of Detail for Point Model Rendering
Felipe Carvalho, Antonio Oliveira, and Ricardo Marroquim (UFRJ)
(pp 35 - 36).
Point-Based representation became a popular alternative
to polygonal meshes for representing 3D geometric
models. 3D photography and scanning systems acquire the
geometry and appearance of real-world objects as point
samples. In this work we present a method for efficiently
creating a hierarchical multiresolution structure for point
models. A variant of the octree is used to partition the
space, while the merging of samples is driven by two error
Frature Pattern for Non-Photorealistic Image Rendering
Anna Regina Corbo and Luiz Henrique de Figueiredo (IMPA)
(pp 37 - 38).
We describe a method for non-photorealistic, “artistic”
rendering of images that uses lines to depict fracture (or
crack) patterns based on image features. The method starts
by sampling the image with a set of points that is good for
stippling. These points are then used as vertices of a minimum
spanning tree which guides the crack propagation in