Helena Cristina da Gama Leitão

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The necessary information to reproduce and keep an organism is codified in acid nucleic molecules. Deepening the knowledge about how the information is stored in these bio-sequences can lead to more efficient methods of comparing genomic sequences. In the present study, we analyzed the quantity of information contained in a DNA sequence that can be useful(More)
We describe here an efficient algorithm for reassembling one or more unknown objects that have been broken or torn into a large number AE of irregular fragments—a problem that often arises in achaeology, art restoration , forensics, and other disciplines. The algorithm compares the curvature-encoded fragment outlines, using a modified dynamic programming(More)
Reassembling unknown broken objects from a large collection of fragments is a common problem in archaeology and other fields. Computer tools have recently been developed, by the authors and by others, which try to help by identifying pairs of fragments with matching outline shapes. Those tools have been successfully tested on small collections of fragments;(More)
We describe an ongoing research project on efficient methods for reconstruction of objects from large collections of irregular fragments, such as ancient pottery, collapsed murals, etc.. Our solution for flat objects uses multiscale matching and constrained dynamic programming, and we are now extending it to curved pottery fragments. We seek collaborative(More)
The integration of a slope map to yield a height (or depth) map is a critical step in many machine vision techniques such as shape-from-shading [4] and multiple-light photometric stereo [5]. These methods have inherent advantages over competing techniques such as laser and stereo triangulation including their low cost, high resolution and their ability to(More)