Proceedings. XV Brazilian Symposium on Computer Graphics and Image Processing

This work aims at the implementation of Brazilian vehicle plate localization using image processing techniques. In this paper, we show how to find the horizontal position of the plate based on its frequency characteristics in the whole vehicle image. Preliminary results show efficiencies above 96% for images in good illumination conditions. View full abstract»

In medical imaging, shell rendering is considered one of the most efficient and effective methods for volume visualization. It requires a compact data structure of voxels and uses the voxel splatting technique for surface and volume rendering. In order to avoid holes in the rendition, the size of the voxels are usually made bigger than the size of the pixels for voxel splatting. In such a case, we... View full abstract»

The watershed transform and the morphological reconstruction are two of the most important operators for image segmentation in the framework of mathematical morphology. In many situations, the segmentation requires the classical watershed transform of a reconstructed image. In this paper, we introduce the IFT-watershed from gray scale marker-a method to compute at same time, the reconstruction and... View full abstract»

We implemented two direct methods for on-line signature verification. First, data produced by a graphics tablet describing a signature to be tested are treated with wavelet transforms to generate features to be nonlinearly confronted with a reference signature chosen among 10 previously stored from the same writer. In order to recover the time dependence lost in the wavelet treatment, we included ... View full abstract»

This paper presents the generation of realistic morphologically neural cells employing a modified L-System. These grammars incorporate functions that refer to the morphological features extracted from natural cells (e.g. branch dendritic, angle and size). A parser is used to generate the neural cells, which can be viewed by a 3D visualization software specifically developed to show the branching s... View full abstract»

Cement is an essential material for the development of the civil construction. The analysis of cement-based materials is useful in the evaluation of mechanical properties, water absorption, air permeability and evolution of hydration degree. The latter is the motivation of this paper. New advantageous techniques of analysis based on the image information are possible using electronic microscopy. W... View full abstract»

This paper evaluates NN and HMM classifiers applied to the handwritten word recognition problem. The goal is analyse the individual and combined performance of these classifiers. They are evaluated considering two different combination strategies and the experiments are performed with the same database and similar feature sets. The strategy proposed takes advantage of the different but complementa... View full abstract»

This work presents a method to output the 3D structure of an urban area from only one aerial photo. The reconstruction is based on the inverse process done when a parallel projection is used to construct a two-dimensional image from a three-dimensional object. A new algorithm for reconstruction is developed and implemented. It recovers depth information by identification of object height on the im... View full abstract»

The watershed transform has been used for image segmentation relying mostly on image gradients. However, background noise tends to produce spurious gradients, that cause over-segmentation and degrade the output of the watershed transform. Also, low-contrast edges produce gradients with small magnitudes, which may cause different regions to be erroneously merged. In this paper, a new technique is p... View full abstract»

The most common goal of automatic bank cheque treatment systems is the recognition of handwritten information. However, in order to do this, it is necessary to use a reliable and efficient process able to identify and to extract the information, which can then be submitted to a further recognition phase. We present a process for identifying and distinguishing between handwritten information and ma... View full abstract»

The problem of image data fusion includes several techniques for data integration from different sensors about a given object. The process can be divided in two stages: (a) pixel interpolation on each observed image to equalize their resolutions; and (b) synthesis of the fused image using the interpolated images. This work proposes the use of projection onto convex sets (POCS) techniques in both s... View full abstract»

This paper describes a decision support system for military operations based on intelligent agents dedicated to the planning and shaping activities. The system has a 3D visualization toolkit for the modeling of the war virtual scenario, which is represented by a 3D mesh using a height map of the actual battle space. The intelligent agents approach is used to support the commanders' decisions in co... View full abstract»

An improved Zernike moment using as a region-based shape descriptor is presented. The improved Zernike moment not only has rotation invariance, but also has scale invariance that the unimproved Zernike moment does not have. The experimental results show that the improved Zernike moment has better invariant properties than unimproved Zernike moment using as region-based shape descriptor. View full abstract»

Off-line signature verification rests on the hypothesis that each writer has similarity among signature samples, with small distortion and scale variability. This kind of distortion represents intrapersonal variability. This paper reports interpersonal and intrapersonal variability influences in a software approach based on a hidden Markov model (HMM) classifier. The experiments have shown error r... View full abstract»

Driving a vehicle is a highly intensive visual information processing task in which traffic sign recognition plays an important role. Reports have shown that a great deal of the crashes at intersections and head-on collisions could be avoided if the driver had an additional half-second to react, and that inattentive drivers are the cause of most crashes. Therefore, this is an interesting field for... View full abstract»

Synthetic aperture radar (SAR) images are corrupted by speckle noise, which degrades the quality and interpretation of the images. Speckle removal provides a better interpretability of SAR images if the technique performs the filtering without loss of spatial resolution and preserves fine details and edges. This work aims to redefine the neighborhood areas around the noisy pixel and in this area t... View full abstract»

This poster describes a terrain editor for the CIVITAS-Cidades Virtuais: Tecnologias de Aprendizagem e Simulacao environment, to be developed by UFRGS-Universidade Federal do Rio Grande do Sul, and used at third and fourth grades of Elementary Schools of Venancio Aires Town-RS-Brasil. MAPPA has the goal of being a computational modeling tool, in terms of two and three dimensions, applied to natura... View full abstract»

This work presents a prototype system for color-based retrieval of images collected on the Web. The images collected are classified in two semantic classes (photographs and graphics) but only photographs are indexed. It basically stores information about regions with the same color in the image (chromatic regions), such as size, position and boundaries with other regions. This data representation ... View full abstract»

We present a hybrid system using computer vision and graphics methods that effectively combines fast automatic 3D model extraction with view-dependent texture mapping for the purpose of real-time person-to-person 3D video teleconferencing. In our approach the problem of creating a dense disparity map is bypassed. We compute only a sparse geometric model, which is textured from multiple cameras usi... View full abstract»

A new three-dimensional reconstruction technique is presented that uses an integer control parameter, denoted β, to produce a family of models from a given set of planar cross-sections. Parameter β supports multiple choices for solving the correspondence problem, i.e., the problem of deciding which regions from two consecutive cross-sections must be connected into a single component. Thu... View full abstract»

This paper describes the process of modelling and implementing a multimedia information system for CECOR-Center for Conservation and Restoration of Cultural Movable Properties. The new system includes a multimedia system which contains information about the restored objects, their materials and techniques, images generated by methods of diagnosis, results of scientific analysis, etc. The new syste... View full abstract»

This paper describes a pipeline for the acquisition and rendering of large real-world environments. In the acquisition phase, we use a laser rangefinder to capture the geometry of an environment, and a digital camera to capture its colors. In the rendering phase, we use a cluster of commodity PCs to render high-resolution images of the environment at interactive frame rates. In this paper, we desc... View full abstract»

Computational processing capacity allows the development of sophisticated interactive animation with different kinds of media resources. Computer games are examples of multimedia software with entertainment and high sophistication characteristics. Such technology allied with cognitive concepts can be used to implement educational software. This poster describes the implementation of a software to ... View full abstract»