.sp 2
.PP
.LP
Click on the "VIEW TIEPOINTS" action button any time you wish to view the
exact coordinates of tiepoints,  or wish to modify the location of the 
tiepoints. When you click on the "VIEW TIEPOINTS" action button, a display
will come up, in which all currently existing tiepoints are displayed.
The tiepoint number (its ID number) is first, followed by a text widget
in which "x,y" is the pixel location of the tiepoint in the source image,
and a text widget in which "x,y" is the pixel location of the corresponding
tiepoint in the target image.  As new tiepoints are added, or old 
tiepoints are deleted, the View Tiepoints display will automatically update.
The display is of a fixed size;  when more than eight tiepoints are present,
the scrollbar on the left of the display must be used to view the later 
tiepoints.
.SH
Modify Tiepoints
.LP
To modify the location of a source tiepoint,
position the cursor in the Source text selection for the tiepoint that you
wish to change.  Change the "x,y" location as desired, remembering that 
tiepoint locations MUST be specified with correct syntax "x,y" and that the
x and y coordinates MUST fall within the image.  Hitting <CR> in the text
selection will cause the tiepoint in question to move to its new location.
The same procedure is followed to modify locations of target tiepoints,
except that it is the Target text selection that is modified.
.sp
.SH
Clearing Images of Tiepoints
.LP
Click on the "CLEAR TIEPOINTS" action button to clear both source and 
target
.sp
.SH
Warping the Image
.LP
Click on "WARP/VIEW IMAGE" to warp the image. A message will pop up asking
if you want to save the resulting warped image. If you do, then input
a filename, otherwise leave the filename blank and click on the ok button.
.LP
The source image will be warped by using a 2nd order polynomial. The
first step is to take all the tiepoints and use a least-squares-fit to
produce four tiepoints. These tiepoints are then used to create the
coefficients for a 2nd order polynomial. This process is actually performed
by  \fBvbilinco\fP. Then the source image along with the coefficients are
system'ed off to warp the image and display the result. The warping is
actually performed by \fBvwarp\fP.
.LP
Note, the WARP/VIEW IMAGE button will only work if both a source and
target image are present (-tp_mode 1).
