h_compute

NAME

h_compute - computes the homography matrix H from a list of correspondances between 2D points of two images

SYNOPSIS

h_compute [-nl|--non-linear] [-hg|--homogeneous] [-?|-h|--help]

DESCRIPTION

h_compute computes the homography matrix H from a list of correspondances between 2D points of two images. It takes its input from the standard input and returns the result (a 3x3 matrix) to the standard output. A homography is a bijection that maps lines to lines. This program can be used for image rectification. In that case, consider using homography.tcl, a GUI using pixelpos(1) to measure image point coordinates, h_compute(1) to compute the homography matrix and h_remap(1) to produce the rectified image.

DATA FORMAT

input stream (or file):

> ul1 vl1 (wl1) ur1 vr1 (wr1)

> ul2 vl2 (wl2) ur2 vr2 (wr2)

> ...

> uln vln (wln) urn vrn (wrn)

uli, vli, (wli): image coordinates of a point on the left image

uri, vri, (wri): image coordinates of a point on the right image: OPTIONS

-h,--help,-?: Returns the manual page

-hg,--homogeneous: homogeneous points are entered: uli vli wli uri vri wri (instead of only: uli vli uri vri)

-nl,--non-linear: this option triggers a non-linear least-square optimisation of the parameters of H, after the linear estimation (Levenberg-Marquardt algorithm). The 'right' coordinates are supposed exact.

AUTHORS

Written by Pierre Smars (first version: 2008)

BUGS

Reports of bugs or problems should be submitted via electronic mail to <smars@yuntech.edu.tw>.

COPYRIGHT

Copyright (C) 2015 Pierre Smars. License GPLv2 <http://www.gnu.org/licenses/gpl-2.0.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.