PHD Thesis - Institute for Computer Graphics and Vision - Graz ...
PHD Thesis - Institute for Computer Graphics and Vision - Graz ...
PHD Thesis - Institute for Computer Graphics and Vision - Graz ...
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6.1. Wide-baseline region matching 94<br />
k=0<br />
k=1<br />
k=n<br />
Figure 6.1: Iterative registration procedure. At k = 0 the patches are aligned by LAF normalization<br />
only. Blue crosses denote the same location in both patches. The red cross indicates the<br />
position with the highest correlation value <strong>for</strong> the point location marked in the right patch. The<br />
dashed square illustrates the correlation window. The shifted point location (red) <strong>and</strong> the original<br />
point location (blue) are used to estimate a homography. The illustration shows only one<br />
point pair, <strong>for</strong> homography estimation additional point correspondences are established (>= 4).<br />
The left patch is then resampled using the homography. After that we are arrived at k=1 <strong>and</strong><br />
the procedure is repeated. Iteratively new homographies are estimated <strong>and</strong> applied to the left<br />
patch until the patches are registered (see k=n). Usually this is achieved in a few number of<br />
iterations. One may note that a part of the correlation window at k=1 is outside the defined<br />
image area. In the illustration the correlation window is drawn enlarged <strong>for</strong> easy reading. In<br />
the implementation one of course has to choose an appropriate window size to avoid problems<br />
on the borders.