The goal is to analyze overlapping objects in an image, usually at microscopic level and for industrial and medical purposes. The task consists of the following research topics: to detect objects which are possibly attached and/or overlapping and to segment the objects, i.e. estimate their contours. This project is a part of LUT Center of Excellence in Research, called Computational Photonics Imaging (COMPHI), in co-operation with LUT Applied Mathematics Laboratory, being associated with Academy of Finland's Center of Excellence in Research in Inverse Mathematics.
The project includes international collaboration with the Laboratory for Image and Video Engineering (LIVE) at The University of Texas at Austin (UT) led by Professor Alan C. Bovik.
People
Sahar Zafari
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visiting UT | Doctoral student | |
Tuomas Eerola
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Office: 2422 | Tel: +358 40 139 3405 | Post-Doctoral Researcher, Adjunct Professor |
Jouni Sampo
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Office: 2508 | Tel: +358 44 337 5672 | University Lecturer |
Heikki Kälviäinen
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Office: 2415 | Tel: +358 40 586 7552 | Professor |
Heikki Haario
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Office: 2409 | Tel: +358 400 814 092 | Professor |
Publications

Segmentation of Overlapping Convex Objects
The thesis presents a framework for segmentation of clustered overlapping convex objects.
Download: PDF

Segmentation of Overlapping Elliptical Objects in Silhouette Images
This paper presents a radial symmetry based method for segmentation of clustered partially overlapping objects with a shape that can be approximated using an ellipse.

Segmentation of Partially Overlapping Nanoparticles Using Concave Points
This paper presents a method to segment multiple partially overlapping nanoparticles in images using concave points and ellipse properties.

Segmentation of Partially Overlapping Convex Objects Using Branch and Bound Algorithm
This paper presents a method to segment multiple partially overlapping nanoparticles in images by formulating the task as a discrete optimization problem and by solving it using branch and bound algorithm.

Comparison of Concave Point Detection Methods for Overlapping Convex Objects Segmentation
This paper presents a comprehensive comparison of existing concave point detection methods that provide an essential cue for segmentation of partially overlapping convex objects.
Resources
Software relases
- A radial symmetry based method for segmentation of overlapping objects
Download the MATLAB code here.
Please cite the following paper in any published work if you use this software.
S. Zafari, T. Eerola, J. Sampo, H. Kalviainen, and H. Haario, Segmentation of Overlapping Elliptical Objects in Silhouette Images, IEEE Transactions on in Image Processing 24(12), 5942-5952, 2015. - A method to segment overlapping nanoparticles using concave points
Download the MATLAB code here.
Please cite the following paper in any published work if you use this software.
S. Zafari, T. Eerola, J. Sampo, H. Kalviainen, and H. Haario, Segmentation of Partially Overlapping Nanoparticles Using Concave Points, in International Symposium on Visual Computing (ISVC 2015), 2015. - A method to segment overlapping nanoparticles using branch and bound algorithm
Download the MATLAB code here.
Please cite the following paper in any published work if you use this software.
S. Zafari, T. Eerola, J. Sampo, H. Kalviainen, and H. Haario, Segmentation of Partially Overlapping Convex Objects Using Branch and Bound Algorithm, in Workshop on Mathematical and Computational Methods in Biomedical Imaging and Image Analysis (MCBMIIA2016), 2016.