Re: [Qgis-developer] Georeferencer produces wrong (shifted) result
Hi Agustin, The points are correct (therefore the errors etc), but the georeferenced image is shifted. May be the datum is not taken into account when the georeferenced image is created. I did a clean checkout, and could finally reproduce the problem: it stems from the fact that your input file has a geotransform, which flips the yaxis of the local coordinate system and changes the origin. As the geotransform plugin does not handle geotransform info correctly, this results in the shift you have observed. Removing the geotransform (e.g. using gdal_translate -co PROFILE=BASELINE - of GTiff Ilerfly125v2.tif Ilerfly125v2-nogeotrans.tif) should give you a file which the georeferencer can handle correctly (you may have to delete the accompanying .aux file, if gdal uses this to keep the geotransform). I had a local patch in the georeferencer which handles geotransform information, so this is why I couldn't reproduce the problem (talk about a mixture of good and bad luck :-)). I will see what is required to make my local changes ready for submission, so we can avoid such subtle problem with georeferenced/pseudo-georeferenced files in the future. As I already mentioned, due to an important deadline at work, I have little time to dedicate to this atm, so it may take a few day... is there a release in the pipeline? cheers, Manuel ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Georeferencer produces wrong (shifted) result
Hello Agustin, No, the correct one is the one on the left, which is the one made with arcgis. I've made an screenshot with transparency: https://sites.google.com/site/openfiles2/home/errorgeorefARCG_QGIStransp.jp eg?attredirects=0d=1 https://sites.google.com/site/openfiles2/home/errorgeorefARCG_QGIStransp.j pegw?attredirects=0d=1 well, with my setup (ca. qgis 1.7), the output of the georeferencer matches the output from ArcGIS pretty accurately (older revision of QGIS, though - haven't tested with head). See my result, georef output in green: http://www.warped-space.de/georef-vs-arcgis.jpeg The qgis georeferencer output can be found here: http://www.warped-space.de/Ilerfly125v2_modifziert.tif Please upload the output you got, both ArcGIS and georeferencer, so that we can rule out problems on the visualization / on-the-fly reprojection side of things. Also, at this point the exact version of your QGIS/GDAL setup could be relevant. There are some possible sources of error for the discrepancy, e.g. gdal, a faulty entry in the qgis projection database, or user error (well, it happens :-)). cheers, Manuel ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Georeferencer produces wrong (shifted) result
Hi Agus, Cannot download http://www.warped-space.de/Ilerfly125v2_modifziert.tif, I get: Oops! This link appears to be broken. sorry, the correct link is http://www.warped-space.de/Ilerfly125v2_modifiziert.tif The procedure we follow is: 1. Set project to CRS EPSG:23031 2. No On the fly reprojection 3. Start georeferencer and open ilerfly125v2.tif and its points file with the settings displayed thats correct, and I did exactly the same (except for the scale change - might be worth checking out), but couldn't reproduce the shiftr (my results match the output of the arcgis version). I've got a lot on my plate right now, but if I find the time I'll try to look this is a regression in qgis or the georeferencer, as I said I'm still on 1.7 atm. How do the residuals look in the georeferencer? Is there a noticable bias (i.e. do they all point in one direction?) Also, make sure there was no world file influencing the unreferenced file (something like Ilerfly125v2.wld), the georeferencer can't handle that. I also noticed that you used a scale change, does the shift also appear without scale change? cheers, Manuel ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Georeferencer produces wrong (shifted) result
Hi Agustin, Please see the screenshot here: https://sites.google.com/site/filestemp2/home/error_georef.jpg?attredirects =0 We've tried polynomia of order 1 and 2 and Helmert, with very similar results. CRS is ED50 UTM31N I've uploaded the input layer and points file to: https://sites.google.com/site/filestemp2/home/Ilerfly125v2.tif?attredirects =0d=1 https://sites.google.com/site/filestemp2/home/Ilerfly125v2.tif.points?attr edirects=0d=1 thanks for your test case. I did a quick test reprojection, but couldn't see a problem with the georeferencer output, i.e. the coordinates generated by the transform fit the destintaion coordinates within a few pixels, putting the max. error somewhere in the ballpark of 1.5m. This relies on the destination coordinates being in ED50 UTM31N. The georeferencer has no support for transforming the destination coordinates, so they need to be specified in the destination CRS. I suspect the discrepancy you are seeing might be a problem with the WGS84-ED50 datum transformation, so it would be helpful if you could provide the ArcGIS output as well. Here you have an screenshot of the comparison to the same image georeferenced with ARCGIS (left) https://sites.google.com/site/filestemp2/home/errorgeorefARCG_QGIS.jpeg?att redirects=0d=1 https://sites.google.com/site/filestemp2/home/errorgeorefARCG_QGIS.jpegw?a ttredirects=0d=1 I guess you meant to say that the right one is from ARCGIS? cheers, Manuel ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Georeferencing output not using compression
Hi Jean Roc, With QGIS 1.7 svn 15861 (osgeo4w), the output of the georeferencing plugin does not take into account the compression setting and so creates a 1go file instead of a 100Mo. I could not reproduce the problem here, so I need a bit more input to zero in on the cause. could you be more specific about the input data format (e.g., was the input file a 1-bit image, 8 bit, or a RGB image, ...), and what compression option was chosen? Seeing the gdalinfo output for input and output files could also be helpful. Also, how did you arrive at the 1go vs 100mo figure? Thank you, Manuel ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Georeferencing output not using compression
Hi Jean Roc, With QGIS 1.7 svn 15861 (osgeo4w), the output of the georeferencing plugin does not take into account the compression setting and so creates a 1go file instead of a 100Mo. Before creating a bug report, could someone confirm the following problem ? I'll look into it. cheers, Manuel ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Raster providers
Hi, the problem seem to be incorrect / inconsistent handling of geotransforms with positive y-axis scale. I have the feeling that at some place the raster extent calculation is performed using a negative y-axis (probably because the CRS is not valid), but some other routines from the gdal raster provider use the directions given by the geotransform. this seemed indeed to be the case, I have commited a fix in r15481 (just adjusting the geotransform to have negative y axis if no geotransform is available). (should fix #3596, but please test) bye, Manuel ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] error in georeferencer
Hi Paolo, Warning: Object::connect: No such signal QgsGCPListWidget::replaceDataPoint( QgsGeorefDataPoint*, int ) in /home/paolo/build/qgis/qgis_unstable/src/plugins/georeferencer/qgsgcplist w idget.cpp:70 All the best. apart from this warning (which shouldn't have any side effects), I haven't found anything which explains the bad_alloc you are getting. I suspect it is a build issue, or the exception is thrown from somewhere else (e.g. the plugin loader). If you have any new insights into this problem feel free to open a bug report. cheers, Manuel ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] error in georeferencer
Hi, And under Ubuntu today we seemed to find no situation in which it would actually allow the transform to be carried out... I can't reproduce either of the bugs (not the bad_alloc() nor the transform failure). Do you have any specifics? cheers, Manuel ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
