Hi, After some test, I confirm the right way to write tfw files for rotated images is the one described here : http://www.omg.unb.ca/~jonnyb/processing/geotiff_tifw_format.html which I can sum up with :
first line of tfw file : pixel resolution * cos(rotation angle in radians) 2nd line : -pixel resolution * sin(rotation angle) 3rd line : -pixel resolution * sin(rotation angle) 4th line : -pixel resolution * cos(rotation angle) 5th and 6th lines still x and y of top left corner. Hope that helps, Happy holidays to all mapserver-users lists readers Guillaume Sueur a écrit : > Hi, > > It doesn't help so much on the precise point of rotation parameters. > I've had the same problem few days ago, and despite many tests I didn't > manage to get a proper rotated image. I fixed that with a "solid" > rotation, set into the image file. But I'm also interested by that approach. > > What are the units of rotation parameters ? I think it's radians, but > maybe directly cos and sin of angle in radian which would be more > adequate tu use in the six parameters transformation... > > Is it counter-clockwise (i.e. trigonometric) direction ? > > is the first one x or y rotation term ? The ESRI support page > (http://support.esri.com/index.cfm?fa=knowledgebase.techarticles.articleShow&d=17489) > is useless. > > the best info I've found are here : > http://www.omg.unb.ca/~jonnyb/processing/geotiff_tifw_format.html > > but I haven't tried yet. > > Guillaume > -- Guillaume SUEUR Expert SIG et OpenSource NEOGEO 46 RUE MATABIAU 31000 TOULOUSE 06 65 58 88 82 Site web : http://www.neogeo-online.net