Ronda Prieto, José IgnacioValdés Morales, AntonioGallego Bonet, Guillermo2023-06-202023-06-2020110920-5691 (Print) 1573-1405 (Online)https://hdl.handle.net/20.500.14352/42061We address the problem of the Euclidean upgrading of a projective calibration of a minimal set of cameras with known pixel shape and otherwise arbitrarily varying intrinsic and extrinsic parameters. To this purpose, we introduce as our basic geometric tool the six-line conic variety (SLCV), consisting in the set of planes intersecting six given lines of 3D space in points of a conic. We show that the set of solutions of the Euclidean upgrading problem for three cameras with known pixel shape can be parameterized in a computationally efficient. As a consequence, we propose an algorithm that performs a Euclidean upgrading with 5 ({theoretical minimum}) or more cameras with the knowledge of the pixel shape as the only constraint. We provide experiments with real images showing the good performance of the technique.engjournal articleopen accessCamera autocalibrationVarying parametersSquare pixelsThree-dimensional reconstructionAbsolute ConicSix Line Conic VarietyInteligencia artificial (Informática)1203.04 Inteligencia Artificial