Leveraging Blur Information for Plenoptic Camera Calibration

This paper presents a novel calibration algorithm for plenoptic cameras, especially the multi-focus configuration, where several types of micro-lenses are used, using raw images only. Current calibration methods rely on simplified projection models, use features from reconstructed images, or require separated calibrations for each type of micro-lens. In the multi-focus configuration, the same part of a scene will demonstrate different amounts of blur according to the micro-lens focal length. Usually, only micro-images with the smallest amount of blur are used. In order to exploit all available data, we propose to explicitly model the defocus blur in a new camera model with the help of our newly introduced Blur Aware Plenoptic (BAP) feature. First, it is used in a pre-calibration step that retrieves initial camera parameters, and second, to express a new cost function to be minimized in our single optimization process. Third, it is exploited to calibrate the relative blur between micro-images. It links This work was supported by the AURA Region and the European Union (FEDER) through the MMII project of CPER 2015-2020 MMaSyF challenge. Mathieu Labussière1 orcid.org/0000-0001-8105-4139 E-mail: mathieu.labu@gmail.com Céline Teulière1 orcid.org/0000-0002-8857-5524 E-mail: celine.teuliere@uca.fr Frédéric Bernardin2 orcid.org/0000-0002-1248-153X E-mail: frederic.bernardin@cerema.fr Omar Ait-Aider1 orcid.org/0000-0002-1711-187X E-mail: omar.ait-aider@uca.fr 1 Université Clermont Auvergne, Clermont Auvergne INP, CNRS, Institut Pascal, F-63000 Clermont-Ferrand, France 2 Cerema, Équipe-projet STI, 10 rue Bernard Palissy, F-63017 ClermontFerrand, France the geometric blur, i.e., the blur circle, to the physical blur, i.e., the point spread function. Finally, we use the resulting blur profile to characterize the camera’s depth of field. Quantitative evaluations in controlled environment on real-world data demonstrate the effectiveness of our calibrations.