A function to digitize 2d landmarks from .jpg files.
Usage
digitize2d(file, nlandmarks, scale)
Arguments
file
Name of jpeg file to be digitized. File names
can be written in manually, including paths, or obtained
using directory/file manipulation functions e.g.,
list.files
nlandmarks
Number of landmarks to be digitized.
scale
Desired length of scale placed on image.
Value
Function returns an n-x-2 .nts file containing the 2d
coordinates of digitized landmarks
Returns text file with the distance in scale
Details
digitize2d is a function to digitize 2d landmarks on
specimen images (.jpg). "nlandmarks" is the number of
landmark points to be digitized by the user. Landmarks
should include "true" landmarks and semilandmarks to be
"slid". For best results, digitizing sequence should
proceed by selecting all true landmark points first,
followed by selection of sliding semi-landmarks. Use
function "curves2d" to select sliding semilandmarks.
After choosing image to digitize, users digitize scale
within image (LEFT mouse button). Then landmark points
can be digitized using the LEFT mouse button. When
selection of n landmarks is completed, an ".nts" file is
created in working directory using the specimen name,
adding "2dcoords.nts" as a suffix.