496 research outputs found
Camera Calibration from Dynamic Silhouettes Using Motion Barcodes
Computing the epipolar geometry between cameras with very different
viewpoints is often problematic as matching points are hard to find. In these
cases, it has been proposed to use information from dynamic objects in the
scene for suggesting point and line correspondences.
We propose a speed up of about two orders of magnitude, as well as an
increase in robustness and accuracy, to methods computing epipolar geometry
from dynamic silhouettes. This improvement is based on a new temporal
signature: motion barcode for lines. Motion barcode is a binary temporal
sequence for lines, indicating for each frame the existence of at least one
foreground pixel on that line. The motion barcodes of two corresponding
epipolar lines are very similar, so the search for corresponding epipolar lines
can be limited only to lines having similar barcodes. The use of motion
barcodes leads to increased speed, accuracy, and robustness in computing the
epipolar geometry.Comment: Update metadat
An Epipolar Line from a Single Pixel
Computing the epipolar geometry from feature points between cameras with very
different viewpoints is often error prone, as an object's appearance can vary
greatly between images. For such cases, it has been shown that using motion
extracted from video can achieve much better results than using a static image.
This paper extends these earlier works based on the scene dynamics. In this
paper we propose a new method to compute the epipolar geometry from a video
stream, by exploiting the following observation: For a pixel p in Image A, all
pixels corresponding to p in Image B are on the same epipolar line.
Equivalently, the image of the line going through camera A's center and p is an
epipolar line in B. Therefore, when cameras A and B are synchronized, the
momentary images of two objects projecting to the same pixel, p, in camera A at
times t1 and t2, lie on an epipolar line in camera B. Based on this observation
we achieve fast and precise computation of epipolar lines. Calibrating cameras
based on our method of finding epipolar lines is much faster and more robust
than previous methods.Comment: WACV 201
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