Parametric Image Alignment Using Enhanced Correlation Coefficient Maximization

Signal Processing and Communications Lab, Department of Computer Engineering and Informatics, University of Patras, Rio-Patras, Greece.
IEEE Transactions on Pattern Analysis and Machine Intelligence (Impact Factor: 5.78). 11/2008; 30(10):1858-65. DOI: 10.1109/TPAMI.2008.113
Source: PubMed


In this work we propose the use of a modified version of the correlation coefficient as a performance criterion for the image alignment problem. The proposed modification has the desirable characteristic of being invariant with respect to photometric distortions. Since the resulting similarity measure is a nonlinear function of the warp parameters, we develop two iterative schemes for its maximization, one based on the forward additive approach and the second on the inverse compositional method. As it is customary in iterative optimization, in each iteration, the nonlinear objective function is approximated by an alternative expression for which the corresponding optimization is simple. In our case we propose an efficient approximation that leads to a closed-form solution (per iteration) which is of low computational complexity, the latter property being particularly strong in our inverse version. The proposed schemes are tested against the Forward Additive Lucas-Kanade and the Simultaneous Inverse Compositional (SIC) algorithm through simulations. Under noisy conditions and photometric distortions, our forward version achieves more accurate alignments and exhibits faster convergence whereas our inverse version has similar performance as the SIC algorithm but at a lower computational complexity.

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    • "Image analysis was performed off line using bespoke MATLAB based software (MATLAB 2013, MathWorks, Natick, Massachusetts, U.S.A). Registration of the ASL images was performed using an enhanced correlation coefficient maximisation algorithm [14]. For each pair of selective/non-selective inversion images, the non-selective inversion image was subtracted from the selective inversion image. "
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    • "An interpolation scheme on the w i all provides pixel-wise weights and the latter, after their normalization, apply to both images. Other than the self-weighting, the steps of the algorithm exactly follow the original version [13]. It is important to note that there is no compositional weighting, but the images, i.e., I n and warped I m , are re-weighted at each iteration. "
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    2013 IEEE International Conference on Computer Vision Workshops (ICCVW); 12/2013
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    • "To summarize, once a temporal registration has been initialized by means of the efficient retrieval step, the ECC algorithm converges to that subframe that maximizes the value of the enhanced correlation coefficient [3]. In other words, the highest number of feature matches provides a rough synchronization, and the maximum similarity defines the final corresponding reference frame. "
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