Hi Caroline! The correct process for obtaining orthophotos from stereo pairs involves a number of complicated steps. I have worked for 10+ years as a photogrammetrist and I am quite certain that simply mosaicking the images will not be enough, particularly if the area has great elevation differences. The correct process also takes into account height measures to compensate for differences in scale, as well as scale differences at the edges of the image. Not to mention the calibration data for the aerial camera that was used.
But it is most likely that the supplier of the aerial images can make real orthophotos for you, or perhaps even has them available as a standard product? I would recommend this as the most cost effective solution. H�lsning/ Best regards Mats.E ________________________ FB Engineering AB S�dra F�rstadsgatan 26 211 43 Malm� OBS nya telefonnummer! Tel: 040-660 2550 Mobil: 0705-27 60 27 Fax: 040-660 2599 e-post: [EMAIL PROTECTED] http://www.fbe.se "Caroline Hilton" <[EMAIL PROTECTED]> 2004-09-06 10:40 S�nd svar till <[EMAIL PROTECTED]> Till <[EMAIL PROTECTED]> Kopia "Joe Piggott" <[EMAIL PROTECTED]> �rende MI-L Rectifying stereo aerial photos Hi Listers A client of mine has purchased some hard-copy aerial stereo-photos and wants to scan them for use as a base layer in MapInfo. These photos are not rectified in any way for digital use, as they are designed for viewing in stereoscopic pairs. Obviously, the client is concerned about the distortion at the edges of the images - he is planning to use 5 photos for the area concerned. Once registered there is about 150m distortion at each photo edge. Placing vector layers onto the images is obviously going to be a problem as registration will be different for each photo image, so they will not currently display properly in MapInfo. Is there any software which will rectify the photos? (is this "ortho-rectifying"?). Or would specific rectified digital images need to be purchased for mosaicing in MapInfo? I have only used digital images, and have not tried using stereographic images for this purpose, so cannot advise. Any advice you may have for using these images in MapInfo would be most welcome. I will forward it to my client. Thanks Caroline ---------------------------------- Dr Caroline Hilton Pelican GeoGraphics Ltd UK [EMAIL PROTECTED] www.pelicangeographics.co.uk --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 13230
