TEST OBJECT WITH RADIAL-CIRCULAR ARRANGEMENT OF REFERENCE POINTS FOR ASSESSING COEFFICIENTS OF RADIAL AND TANGENTIAL DISTORTION Russian patent published in 2023 - IPC G01M11/02 G06T7/80 

FIELD: computer technology.

SUBSTANCE: used to estimate the ratios of radial and tangential lens distortion and the matrix of internal parameters of the camera. The essence of the invention is as follows. The test object for assessing the radial and tangential distortion coefficients is a flat base with an applied calibration template in the form of a set of nodal points located at the intersections of uniformly distributed N₀ concentric circles with a constant radial increment Δr and N_p radial beams with a constant angular increment Δϕ=360°/N_p. At the same time, on non-peripheral concentric circles, the nodal reference points M_ji are not placed at all intersections of the j-th concentric circle and the i-th radial ray: when moving from the periphery of the test object to its centre, starting from the number of the concentric circle j=(N₀-x), where x={a, b, c, d,…} - natural number, 1≤a<b<c<d<…≤N₀-1, enter decimation coefficients along the angle d_x={d_a, d_b, d_c, d_d,…}, where 2≤d_a<d_b<d_c<d_d<…≤N_p/2 - natural numbers. Taking into account the decimation coefficients, the reference points are placed only at the intersections of the j-th concentric circle and each (d_x+m_x) radial ray, where m_x={m_a, m_b, m_c, m_d,…} - non-negative integer, m_x<d_x.

EFFECT: uniform density of images of reference points of the calibration range.

1 cl, 1 dwg