reads coordinates from raster image
pts = GRABXY(fName, ax)
Input:
fName String, path to the image file.
ax (x,y) coordinates of the three axis points, with dimensions
of 2x3. If ax is omitted or empty, GRABXY just shows the
image.
Output:
pts Matrix, where the first row are the x coordinates the
second row is the y coordinates.
How to use the function?
You need an image where you know the coordinates of three points. These
coordinates has to be given as the ax input to the grabxy() function.
After calling the function, it shows the image file and the first three
mouse clicks on the figure will determine the position of the three
predefined points (shown as red circles) given in ax. Any other click
afterwards will grab coordinates (shown as green circles). The coordinates
of the green circles will be returned. If you don't want to grab more
points, just right click anywhere on the figure.