=head1 NAME

linefind - Detect vertical features in images

=head1 SYNOPSIS

B<linefind> [options] -o I<output.pto> I<input.pto>

=head1 DESCRIPTION

B<linefind> is a detector for vertical features in images. It tries to find
vertical lines using the same algorithm as Calibrate_lens_gui and assigns
vertical control points to them. The detection runs on the source images, if
the input images are rectilinear images. In the other cases (e. g. fisheye
images) the input images are reprojected to an equirectangular projection and
the detection works on the reprojected images. It uses the roll value, saved
in the pto project file, to determine what is "top" and "bottom". So before
running linefind check that your roll values are correct (E. g. when using
images straight from the camera, use a roll value of 0 for landscape and a
value of 90 or 270 for portrait images. If your camera has an orientation
sensor, Hugin can detect this information automatically and sets the roll
value accordingly when adding such images into Hugin.

=head1 OPTIONS

=over

=item B<-o|--output> output.pto

Output Hugin PTO file. Default: '<filename>_line.pto'.

=item B<-l|--lines> num

The maximum number of lines added per image (default: 5) Attention: Keep in
mind that more vertical control points will dominate the optimisation in favour
of "normal" control points.

=item B<-i|--image> num

Image number(s) to process.  Normally linefind tries to find vertical lines in
all images of the project file. If you want to limit the detection to some
selected images, you can use this parameter. Can be used multiple times.

=item B<-h|--help>

shows help

=back

=head1 AUTHORS

Thomas Modes, line detection code based on L<calibrate_lens> by Tim Nugent

