README updates

1 files changed, 29 insertions, 16 deletions

diff --git a/README b/README
index 025e0fb..37e3b97 100644
--- a/README
+++ b/README
@@ -1,3 +1,6 @@
+gipfel
+======
+
 Description
 -----------
 gipfel helps to find the names of mountains or points of interest
@@ -8,7 +11,13 @@ on the picture, gipfel can compute all parameters needed to compute the
 positions of other mountains on the picture.
 gipfel can also be used to play around with the parameters manually. But be
 warned: It is pretty difficult to find the right parameters for a given
-picture manually.
+picture manually.  
+You can think of gipfel as a georeferencing software for arbitrary images
+(not only satelite images or maps).  
+gipfel also has an image stitching mode, which allows to generate
+panorama images from multiple images that have been referenced with gipfel.
+The nice thing about image stitching is that it reuses the code that
+already exists for referencing images.  
 
 Requirements
 ------------
@@ -35,6 +44,8 @@ You should now see a control window and the actual picture.
 Additionally a "Choose Viewpoint" window should pop up, where you can search
 for the viewpoint from which the picture was taken. Select a viewpoint and 
 click "Ok".
+Alternatively, you can enter the GPS coordinate of the viewpoint directly in
+the control window.  
 You can now use the controls in the control window to modify the view
 parameters. These are:
 * View direction
@@ -48,15 +59,16 @@ mountains, which you already recognize on the picture.
 Now middle-click on the small cross at the left of the name to mark it.
 It should turn red. Now you can drag it with the left mouse button pressed
 to the position of the mountain on the picture.
-If you have positioned at least two mountains, you can now click on
-the "comp" button in the control window. 
+If you have positioned at least two mountains, you can click on
+the "comp" button in the control window to compute the
+parameters of the picture.
 
 You may also want to have a look at the screen video at
 <http://www.ecademix.com/JohannesHofmann/gipfel.avi>
 for an example session.
 
-The Data File
--------------
+Data File
+---------
 As stated before, gipfel needs GPS input data. The input data must be
 an ASCII file with one line per mountain / point of interest.
 Each line must contain the following values separated by a comma:
@@ -68,18 +80,18 @@ Each line must contain the following values separated by a comma:
 The following line is a valid example:
 SMTSBG,Simetsberg,,47.56617,11.25358,1836
 
-Fortunately, there is a great website http://www.alpin-koordinaten.de, where
-you can download a suitable file containg quite a lot of data mostly 
+Fortunately, there is a great website <http://www.alpin-koordinaten.de>,
+where you can download a suitable file containg quite a lot of data mostly 
 concerning the alps:
 Click on the "Suchen" button and the click on the diskette symbol below
 the first table then select "Fugawi 3 TXT" format and click on "Download".
 
 Obviously you can easily add your own entries to the data file or add them
-to the database at http://www.alpin-koordinaten.de.
+to the database at <http://www.alpin-koordinaten.de>.
 
-Thanks to the kind permission of the owners of www.alpin-koordinaten.de, the 
-standard gipfel tarball now includes a default datafile generated by 
-www.alpin-koordinaten.de
+Thanks to the kind permission of the creators of
+<http://www.alpin-koordinaten.de>, the standard gipfel tarball includes
+a default datafile generated by <http://www.alpin-koordinaten.de>.
 
 GPS Tracks
 ----------
@@ -164,9 +176,10 @@ Lens Distortion
 Typical lenses especially wide-angle lenses diverge from the optimal
 rectilinear projection.
 gipfel can now partly correct the resulting errors.
-To this end gipfel uses a standard distortion model with two parameters 
-(k0 and k1). Depending on these values, the distance d of an image point
-from the center is modified by (k0 * d + k1 * d ^ 2).
+To this end gipfel uses a standard distortion model with three parameters 
+(k0, k1, and x0). Depending on these values, the distance d of an image
+point from the center is modified by (k0 * d + k1 * d ^ 2).
+x0 is the main point offset in X direction.  
 
 If you mark and position more than 3 mountains on an image, gipfel
 tries to correct lens distortion. You can see that the flags turn
@@ -176,8 +189,8 @@ focal length you can save the distortion profile (Distortion/Save Profile).
 Whenever you now open an image taken with this camera model and focal
 length, gipfel will use this distortion profile.
 The distortion profiles are stored in the 
-$HOME/.fltk/Johannes.HofmannATgmx.de/gipfel directory and can also be
-edited manually.
+	$HOME/.fltk/Johannes.HofmannATgmx.de/gipfel
+directory and can also be edited manually.
 Independent of the distortion profiles one can also modify the
 distortion parameters per image.
 Distortion correction is also used when stitching panorama images.