Hi, Suzanne: Agree with Kazuhiko with the "rectification" or "orthorectification" issue.
For aerial photos, we are using a 2D/3D tool, AirPhoto, developed by Irwin Scollar at the Cologne University, Germany. They have a mirror site in the University of Edinburgh. We have done urban analysis growth with AirPhoto and it works fine. It has nice features to define control points, it can rectify over hilly terrain if you have a DEM, it accepts different input and output formats, and the developer is very responsive and constantly improving it. AirPhoto is not free but reasonably priced, please check the site below. http://www.uni-koeln.de/~al001/airphoto.html Regards, Fernando Mazariegos Mapelligent Geomarketing in Central America -----Original Message----- From: DUNNE, Suzanne [mailto:SDUNNE@;glos.ac.uk] Sent: Thursday, October 24, 2002 5:02 AM To: [EMAIL PROTECTED] Subject: MI-L aerial photos Dear all, I have some aerial photos from different time periods that I would like to register acurately in MapInfo - acurately enough so that I can digitise river channels over it and look at the change in extent of the channel. However when you zoom in on a black and white aerial photo the boundaries that you would like to use as points to register are way too fuzzy to do it accurately. I set the dpi so that the file is about 1-1.6MB, jpeg/gif image. (I am soon to have access to a computer with 36 GB, 256MB of RAM, Pentium 4). Does anyone know how this is usually done? (without buying extraordinarily expensive software) cheers, Suzanne. [EMAIL PROTECTED] --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 3755 --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 3765
