Index
Cover
Point Mapping
Point Mapping
Your main task when using any rectifier is mapping points on your photograph to
points in the real world so you need to become familiar with the
Point Mapping
dialogue box. You should also look at the section on
taking measurements
for some ideas about establishing your coordinate system.
Placing the points in the source image
is generally most easily done by establishing them with a double mouse click
near where you want them then moving them into position in the window of the
Point Mapping
dialogue box, where you can zoom in for precision placement.
note:
If you are having trouble placing the point exactly where you want it the arrow keys will
move it in one pixel increments after you have selected it while you hold down the left
mouse button.
Things to remember
- The pixel coordinate system has its 0,0 at the upper left hand corner and it increases
to the right and downwards
- The world coordinate system was defined by you but typically starts at the lower left
and increases to the right and up.
- 3D coordinates were probably defined by your survey instrument and will work fine
as long as they are consistent and you have correctly defined the
axises.
- Points not on the rectification plane will give spurious results.
When using 3D coordinates these errors should show up in the
Z Deviation
column, to the right of the
Residuals
in the
Point List
window.
Up
Index
Cover
Inquiries to:
steve@icomos.org
Generated by: CART
(Thu Sep 20 17:56:23 2007
)