Greg Phillips wrote:
> 
> At a MUG UK demo of Vertical Mapper recently I raised the question as to whether 
> orthorectification and rubber sheeting might be added to VM as a future development, 
> as it is the logical Raster extension to MapInfo.  In my opinion that added 
> functionality would really extend the tools available to exclusive MapInfo users, 
> and it seems that having acquired Vertical Mapper that MapInfo are in the perfect 
> position to enhance this product.

VM is already a useful tool warp vector layers. As an experiment,
I warped a layer of streets to match an orthophoto using a
combination of Vertical Mapper and MapBasic. Here's the steps:

1. Create a layer of line segments drawn from a point on the
photo to the corresponding point in the vector layer.

2. Determine the x and y differences of the end points and store
these values in a point table where the points represent your
correct locations. The x and y offset represent the error in the
vector layer at each point.

3. create a grid of the x error and one of the y error.

4. Now for each node in your vector layer's objects, pick off the
x and y error offsets from the grids (reverse gridding) and shift
the node by those amounts in both the x and y directions.

If you are consistent and get your signs right, the result comes
out surprisingly well.

-- 
- Bill Thoen
------------------------------------------------------------ 
GISnet, 1401 Walnut St., Suite C, Boulder, CO  80302
tel: 303-786-9961, fax: 303-443-4856
http://www.gisnet.com/
------------------------------------------------------------

---------------------------------------------------------------------
List hosting provided by Directions Magazine | www.directionsmag.com |
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Message number: 8946

Reply via email to