USAGE
-----


This document describes using the stereo program.
It should be read after reading my MSc thesis, for a clear
understanding of stereo-metrological procedures.

Upon running 'main/display' a main window will appear with
a button array, an edit window, and a graphics window.
To get data out of a pair of images you can follow this procedure:


- Scan the image at in 256 grey level format. TARGA (.tga files) and
TIFF (.tif or .tiff files) image file formats are recognised.
ONLY uncompressed class G tiff files are supported. These are
uncompressed 8 bits-per-pixel grey scale image files that most
scanner software will support. If you have another image file
format that you would like to use then get the 'Image Magick'
package off the sunsite --- it can convert between any image file
format. Beware that some programs reduce the resolution when converting
large images, or may not be able to handle very large images.


- Once you have the image, load it with the 'Load Image' button.
It will take the image a long time to load, because a scaled
image has to be created, and the image has to columnated for
the disk caching mechanism. Load the other image also.


- Load the calibration file with 'Load Cal'. An example calibration
file with six calibration points is:

1421.4      538.6       113.9
3143.6      -0.7       547.0
3109.0      673.6       211.7
1785.2      -357.1       270.1
3186.4      554.0       265.5
2778.3      -508.9       650.0

representing the x, y and z three dimensional coordinates of
each point.


- Place a marker on each calibration point in one image. You must
place the markers in the same order as in the calibration file.
You can move a marker by holding the Control key down, and
pressing the left mouse button: the closest marker to the cursor
will be moved to the cursor. You can delete a marker by holding down
the control key and pressing the right mouse button: the closest
marker will be deleted (but watch the order of the markers).
The right mouse button will zoom in the zoom box.


- After you have clicked on each calibration point, you can now
calibrate the camera parameters. If you think that one or two
markers may be inaccurate, click on 'Leave Out'. If you know the image
aspect ratio in percent (from experience with many calibrations)
set it to the desired value, otherwise set it to zero. Click
on calibrate. After thinking for some time, the camera parameters will
be found. Click on 'Cam Data' to see the camera position. If the
error is acceptable, continue with the other image.


- Clear the markers and save the desktop. You will be able to retrieve the
the desktop with ready calibrated images at any later stage. Saving the
desktop however does not save the editor file.


- You can now proceed with fitting geometric primitives (see the
section in my thesis). You may want to first load the example
data 'test_data/lee.txt' in the source tree. Do this by clicking in the editor
window, and using the 'File' menu to load a file. When the file 'lee.txt'
is loaded.  Hit Alt-R to 'R'ender the image. The graphics window
can then be used to rotate and scale the image. See the file 
'3dtext.c' for an (innaccurate) reference on what the various editor
commands do. The file 'test_data/3dtest.txt contains a further example
(which was invented and did not come from actual images).


