Le vendredi 10 août 2012 22:28:34, Jorge Arevalo a écrit : > Hi, > > Many thanks for your response, Martin. So, it doesn't need to be a > mistake. Just a flipped image. > > The doubt raised because, for example, gdalbuildvrt doesn't accept ns > positive resolution values. Looking at this old ticket > http://trac.osgeo.org/gdal/ticket/3432, seems that that kind of raster > data can't be mosaiced. You get an error. I don't understand why. > > I know cartesian coordinate system sets the origin in the bottom left > corner, while images set the origin in the top left corner. So, the > ns resolution of a georeferenced image is negative. Otherwise, you get > a south up image. But... if all the images you want to mosaic have > this "problem" (positive ns resolution), why I can't mosaic them using > gdalbuiltvrt?
Jorge, You could certainly remove this limitation of gdalbuildvrt. I put it because I'm lazy and don't usually deal with south-up images (and because images with postive ns resolution are in 99% of the cases in fact ungeoreferenced images, which you don't want to mosaic). I suspect that just removing the test might make things work. I let you experiment with that. _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev