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Calibration of non-overlapped camera network using lidar data

We propose the utilization of Laser Range Finder (LRF) data covering the area of the camera network to support the calibration process and develop a semi-automated methodology allowing quick and precise calibration of  large camera networks. The proposed methods have been tested in a real  urban environment and have been applied to create direct mappings (homographies)  between image coordinates and world points in the ground plane (walking  areas) to support person and robot detection and localization algorithms.

More details in the paper published in IROS09



Calibration explanation

3d data laser points used for calibrating camera network
   
3D segmentation using 3d point clouds

Segmentation of planar surfaces in urban scenarios is challenging because the data acquired is typically  sparsely sampled, incomplete, and noisy. The algorithm is motivated by Felzenszwals's algorithm to 2D image segmentation; and is extended  to deal with non-uniformly sampled 3D range data using an approximate  nearest neighbor search. Inter-point distances are sorted in increasing  order and this list of distances is traversed growing planar regions  that satisfy both local and global variation of distance and curvature.
The algorithm runs in O(n log n) and compares favorably with other  region growing mechanisms based on Expectation Maximization.  A pair of applications of the segmented  results are shown, a) to derive traversability maps, and b) to calibrate  a camera network.

More details in the paper published in ECMR09
Segmentation explanation

Dataset used for segmentation

Segmentation of dynamic objects using laser and cameras

We present a method to segment dynamic objects from high-resolution low-rate  laser scans. Data points are tagged as static or dynamic based on the  classification of pixel data from registered imagery. Per-pixel background  classes are adapted online as Gaussian mixtures, and their matching 3D points  are classified accordingly. Special attention is paid to the correct calibration and synchronization of the scanner with the the accessory camera. Results of the method are shown for a small indoor sequence with several people following arbitrarily different trajectories.

More details in the paper published in ECMR11
   
Segmentaing a sequence
Camera calibration

Objects segmented
Indoor points cloud
   
Dynamic object detection in lidar data

My research is finding methods that can detect dynamics objects given 2 points clouds of the same scene. We are focused in segment object in dynamic scenes with a mobile platform.



Calibration and detectiong automatic chessboard
Segmenting dynamic objects on points clouds