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Re: [Openev-discuss] auto rotate GeoTIFF to align to map grid
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From: Max B. <max...@at...> - 2003-12-11 15:07:37
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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta http-equiv="Content-Type" content="text/html;charset=ISO-8859-1"> <title></title> </head> <body text="#000000" bgcolor="#ffffff"> Hi Frank,<br> I have many plain TIFF files of scenes that didnt have georeferencing or tiepoint info available at the time they were created. I'd like to revisit these and add either georeferencing or tie-point data (so that they can be warped ). What are the details on the ".tfw" files you mentioned? Once I've done that, how does one create a GeoTiff from it ?<br> <br> ...Max<br> <pre class="moz-signature" DEFANGED_cols="72">-- Max Buchheit Email: <a class="moz-txt-link-abbreviated" href="mailto:max...@at...">max...@at...</a> Phone:(613) 727-5169,ext 226 or 727-1087 Web : <a class="moz-txt-link-abbreviated" href="http://www.atlantis-scientific.com">www.atlantis-scientific.com</a> </pre> <br> <br> <a class="moz-txt-link-abbreviated" href="mailto:ope...@li...">ope...@li...</a> wrote:<br> <blockquote type="cite" cite="mid...@sc..."> <pre wrap=""> --__--__-- Message: 1 From: "David Lugan" <a class="moz-txt-link-rfc2396E" href="mailto:dav...@ho..."><dav...@ho...></a> To: <a class="moz-txt-link-abbreviated" href="mailto:ope...@li...">ope...@li...</a> Date: Wed, 10 Dec 2003 11:45:32 -0800 Subject: [Openev-discuss] auto rotate GeoTIFF to align to map grid How do I load a GeoTIFF and automatically rotate it so the corners of the file align with the map grid? For example: 1. upper-left corner longitude = lower-left corner longitude 2. upper-left corner latitude = upper-right corner latitude 3. lower-left corner latitude = lower-right corner latitude 4. upper-right corner longitude = lower-right corner longitude ... Right now I am trying to get OpenEV to compile under VC++ .NET Windows XP (maybe today). I t1hink studying the openEV rotation may give me an idea but I still don't see how to do an auto-rotate. tia - David Lugan _________________________________________________________________ Take advantage of our best MSN Dial-up offer of the year — six months @$9.95/month. Sign up now! <a class="moz-txt-link-freetext" href="http://join.msn.com/?page=dept/dialup">http://join.msn.com/?page=dept/dialup</a> --__--__-- Message: 2 Date: Wed, 10 Dec 2003 15:03:22 -0500 From: Frank Warmerdam <a class="moz-txt-link-rfc2396E" href="mailto:war...@po..."><war...@po...></a> To: David Lugan <a class="moz-txt-link-rfc2396E" href="mailto:dav...@ho..."><dav...@ho...></a> Cc: <a class="moz-txt-link-abbreviated" href="mailto:ope...@li...">ope...@li...</a> Subject: Re: [Openev-discuss] auto rotate GeoTIFF to align to map grid David Lugan wrote: </pre> <blockquote type="cite"> <pre wrap="">How do I load a GeoTIFF and automatically rotate it so the corners of the file align with the map grid? For example: 1. upper-left corner longitude = lower-left corner longitude 2. upper-left corner latitude = upper-right corner latitude 3. lower-left corner latitude = lower-right corner latitude 4. upper-right corner longitude = lower-right corner longitude ... Right now I am trying to get OpenEV to compile under VC++ .NET Windows XP (maybe today). I t1hink studying the openEV rotation may give me an idea but I still don't see how to do an auto-rotate. </pre> </blockquote> <pre wrap=""><!----> David, If a geotiff has rotational coefficients then OpenEV will take these into account, but still draw the raster north up (hence rotated). In a GeoTIFF file you would need to use the "matrix" form, rather than the tiepoint and pixel size formulation for the georeferencing to get a rotated effect. Alternatively you could use a plain TIFF file, and a .tfw in which it is easier to prepare the rotational coefficients. Note that internally OpenEV accomplishes it's rotation by drawing everything as textures on a triangulated mesh, and by just transforming the mesh coordinates. If the stuff about .tfw files isn't clear let me know and I could give the details. Best regards, </pre> </blockquote> <pre DEFANGED_cols="72" class="moz-signature"> </pre> </body> </html> |