Abstract book (pdf) - ICPR 2010

orientation histograms computed on different feature regions, commonly divided by using a regular Cartesian grid or a
log-polar grid. In order to achieve rotation invariance, feature patches have to be generally rotated in the direction of the
dominant gradient orientation. In this paper we present a modification of the GLOH descriptor, a SIFT-based descriptor
based on a log-polar grid, which avoids to rotate the feature patch before computing the descriptor since predefined discrete
orientations can be easily derived by shifting the descriptor vector. The proposed descriptors, called sGLOH and sGLOH+,
have been compared with the SIFT descriptor on the Oxford image dataset, with good results which point out its robustness
and stability.
09:00-11:10, Paper ThAT8.11
Inpainting Large Missing Regions in Range Images
Bhavsar, Arnav, Indian Inst. of Tech. Madras
Ambasamudram, Rajagopalan, Indian Inst. of Tech. Madras
We propose a technique to in paint large missing regions in range images. Such a technique can be used to restore degraded/occluded
range maps. It can also serve to reconstruct dense depth maps from sparse measurements which can speed
up the acquisition. Our method uses the visual cue from segmentation of an intensity image registered to the range image.
Our approach enforces that pixels in the same segment should have similar range. Our simple strategy involves planefitting
and local medians over segments to compute local energies for labeling unknown pixels. Our results exhibit high
quality in painting with very low errors.
09:00-11:10, Paper ThAT8.12
Angular Variation as a Monocular Cue for Spatial Perception
Aranda, Joan, UPC
Navarro, Agustin A., UPC
Perspective projection presents objects as they are naturally seen by the eye. However, this type of mapping strongly
distorts their geometric properties as angles, which are not preserved under perspective transformations. In this work, this
angular variation serves to model the visual effect of perspective projection. Thus, knowing that the angular distortion depends
on the point of view of the observer, it is demonstrated that it is possible to determine the pose of an object as a consequence
of its perspective distortion. It is a computational approach to direct perception in which spatial information of
a scene is calculated directly from the optic array. Experimental results show the robustness provided by the use of angles
and establishes this 3D measurement technique as an emulation of a visual perception process.
09:00-11:10, Paper ThAT8.13
An Exploration Scheme for Large Images: Application to Breast Cancer Grading
Veillard, Antoine, NUS
Lomenie, Nicolas, CNRS
Racoceanu, Daniel, CNRS - French National Res. Center
Most research works focus on pattern recognition within a small sample images but strategies for running efficiently these
algorithms over large images are rarely if ever specifically considered. In particular, the new generation of satellite and
microscopic images are acquired at a very high resolution and a very high daily rate. We propose an efficient, generic
strategy to explore large images by combining computational geometry tools with a local signal measure of relevance in
a dynamic sampling framework. An application to breast cancer grading from huge histopathological images illustrates
the benefit of such a general strategy for new major applications in the field of microscopy.
09:00-11:10, Paper ThAT8.14
3D Human Body Modeling using Range Data
Yamauchi, Koichiro, Keio Univ.
Bhanu, Bir, Univ. of California
Saito, Hideo, Keio Univ.
For the 3D modeling of walking humans the determination of body pose and extraction of body parts, from the sensed 3D
range data, are challenging image processing problems. Real body data may have holes because of self-occlusions and
grazing angle views. Most of the existing modeling methods rely on direct fitting a 3D model into the data without con-
- 252 -