That's a whole different game... You'd basically point to known or recognisable locations in your image (the 'slave') and point to the equivalent point in a geometrically correct 'master', eg. the vector you have, or a scanned map or a set of GPS point, etc. For a theoretical overview, see eg. http://www.cnr.berkeley.edu/~gong/textbook/chapter4/html/sect44.htm In practice, you'd use some basic GIS or Remote Sensing software that can do that... -- Barend Köbben International Institute for Geo-information Sciences and Earth Observation (ITC) PO Box 6, 7500AA Enschede (The Netherlands) ph: +31-(0)534874253; mobile: +31-(0)622344955
________________________________ From: Bradley Mclain [mailto:[EMAIL PROTECTED] Sent: Sun 04/02/2007 22:46 To: Barend Köbben; [email protected] Subject: Re: [UMN_MAPSERVER-USERS] Raster Image and Shapefile Alignment How would you suggest I go about re-doing the georeferencing? Brad >From: Barend Köbben <[EMAIL PROTECTED]> >To: Bradley Mclain <[EMAIL PROTECTED]> >Subject: Re: [UMN_MAPSERVER-USERS] Raster Image and Shapefile Alignment >Date: Fri, 02 Feb 2007 09:19:33 +0100 > >HI, > >The shapefile is in an Australian projection, and your raster has been >georeferenced to *something*, but there's no telling to what projection >they >georef'd it, because there's no projection info in the raster file. > >In other words: someone told the raster "you fit in this place in the >world, >between XY 1 and XY 2", but they didn't specify in what projection system >those XY's are. You would suppose to the same projection the vector is in, >and in that case, the fit will be OK as long as the projection of the shape >remains the same as it was when the raster was georef'd to it. But if one >changes that projection, or maybe only the Datum, as tends to happen >unexpectedly when you transfer files from one GIS to another, things will >misalign... > >To make matters worse, it can also just be a case of sloppy >georeferencing... > >Without knowing the rasterprojection, there's no solution, except re-doing >the georeferencing... > >On 02-02-2007 07:16, "Bradley Mclain" <[EMAIL PROTECTED]> wrote: > > > Umm I know very little about geodata so i'll simply attach the readouts >from > > ogrinfo and gdalinfo so you can see for yourself cause i have no idea. >:) > > > > If it helps any they are only out slightly. (as shown in attached > > screenshot) > > > > Bradley Mclain > > > > > > > > > >> From: "Gregor Mosheh" <[EMAIL PROTECTED]> > >> Reply-To: [EMAIL PROTECTED] > >> To: "Brad_Mclain" <[EMAIL PROTECTED]> > >> CC: [email protected] > >> Subject: Re: [UMN_MAPSERVER-USERS] Raster Image and Shapefile Alignment > >> Date: Thu, 1 Feb 2007 23:02:05 -0700 (MST) > >> > >>> Ok here is the sitution I have a raster image and shapefile data but >the > >>> two do not line up correctly. > >> > >> Are you positive that they're both in the same projection? Or, do you >know > >> the projection for each one? I've had so many annoyances in the past >where > >> something was in "CA State Plane II" and then had to figure out which >of > >> the five CA State Plane II projections it really was. :) > >> > >> If you know the projection for each, be sure to specify it in your >mapfile > >> using a PROJECTION block in your LAYER block. You can probably get more > >> help on that once we know a bit more about the matter. > >> > >> Best of luck, Brad. > >> > >> -G > >> > > > > _________________________________________________________________ > > Join the millions of Australians using Live Search. Try live.com.au > > >http://ninemsn.com.au/share/redir/adTrack.asp?mode=click&clientID=740&referral > > =million&URL=http://live.com.au <http://live.com.au/> > _________________________________________________________________ Advertisement: Meet Sexy Singles Today @ Lavalife - Click here http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Flavalife9%2Eninemsn%2Ecom%2Eau%2Fclickthru%2Fclickthru%2Eact%3Fid%3Dninemsn%26context%3Dan99%26locale%3Den%5FAU%26a%3D23769&_t=754951090&_r=endtext_lavalife_dec_meet&_m=EXT
