Principled Design and Implementation of Steerable Detectors
J. Fageot, V. Uhlmann, Z. Püspöki, B. Beck, M. Unser, A. Depeursinge
IEEE Transactions on Image Processing, vol. 30, pp. 4465–4478, 2021.
We provide a complete pipeline for the detection of patterns of interest in an image. In our approach, the patterns are assumed to be adequately modeled by a known template, and are located at unknown positions and orientations that we aim at retrieving. We propose a continuous-domain additive image model, where the analyzed image is the sum of the patterns to localize and a background with self-similar isotropic power-spectrum. We are then able to compute the optimal filter fulfilling the SNR criterion based on one single template and background pair: it strongly responds to the template while being optimally decoupled from the background model. In addition, we constrain our filter to be steerable, which allows for a fast template detection together with orientation estimation. In practice, the implementation requires to discretize a continuous-domain formulation on polar grids, which is performed using quadratic radial B-splines. We demonstrate the practical usefulness of our method on a variety of template approximation and pattern detection experiments. We show that the detection performance drastically improves when we exploit the statistics of the background via its power-spectrum decay, which we refer to as spectral-shaping. The proposed scheme outperforms state-of-the-art steerable methods by up to 50% of absolute detection performance.
@ARTICLE(http://bigwww.epfl.ch/publications/fageot2101.html,
AUTHOR="Fageot, J. and Uhlmann, V. and P{\"{u}}sp{\"{o}}ki, Z. and Beck,
B. and Unser, M. and Depeursinge, A.",
TITLE="Principled Design and Implementation of Steerable Detectors",
JOURNAL="{IEEE} Transactions on Image Processing",
YEAR="2021",
volume="30",
number="",
pages="4465--4478",
month="",
note="")