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 claimed photogrammetric calibration method for estimating the ratios of radial and tangential lens distortion and the matrix of internal parameters of the camera is based on shooting a test site of nodal points located at the intersections of uniformly distributed No concentric circles and Np radial directions. Based on the results of shooting in frames from the camera, the pixel coordinates of the nodal points of the site are estimated with subpixel accuracy and the ratios of the distortion mathematical model and the elements of the matrix of internal parameters of the camera are calculated from them. The test site is surveyed m≥2 times and before each subsequent exposure, it is rotated in roll by an angleδϕ≈Δϕ/m, where Δϕ =360°/Ν p is the angular size of the site's radial sector. In this case, the site is centered along the lines of the frame center markers vertically and horizontally and is controlled by the point of intersection of the markers in the center of the circle of the smallest radius on the image from the camera, and the initial angular position is controlled by the horizontal position of the line of the frame center marker in the radial sectors of the site image, adjacent to its horizontal axis of symmetry corresponding to the radial branches of the site with the numbers “0-Np/2”.
EFFECT: solution of an overdetermined system of equations of projective geometry for a priori known in the coordinate system of the calibration site of the spatial coordinates of its nodal points.
1 cl, 2 dwg
