Re: [Viking-devel] Using local maps: how?
On Saturday 21 May 2011 01:19:46 Greg Troxel wrote: But probably implies local adjustments? That would explain some discrepancies in scale I am seeing. In theory I should have 5 meters per pixel but end up having to say 7 for a better match. All these local adjustments will render my automation quite difficult. Ideally, I would like to cover an area that is roughly 250km x 250km... So probably viking converts lat/lon to UTM, and then just uses the georef map as if it is the right zone. I think what you need to do is to find the upper left pixel in WGS84 UTM. Check out the following program - probably viking should use it at some point, but it's the standard approach to coordinate conversion in the open source world: http://trac.osgeo.org/proj/ This looks exactly like the tool I was looking for, which should allow me to do everything with scripts. Thanks a lot. Fred P.S. And yes, indeed, using it in viking would offer so much flexibility! ;-) -- What Every C/C++ and Fortran developer Should Know! Read this article and learn how Intel has extended the reach of its next-generation tools to help Windows* and Linux* C/C++ and Fortran developers boost performance applications - including clusters. http://p.sf.net/sfu/intel-dev2devmay ___ Viking-devel mailing list Viking-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/viking-devel Viking home page: http://viking.sf.net/
Re: [Viking-devel] Using local maps: how?
On Friday 20 May 2011 21:30:37 Fred Labrosse wrote: On Friday 20 May 2011 21:03:56 Fred Labrosse wrote: All, Not really a devel question but the website said to email this list so here it is. I have been using viking for a while, so far using openstreetmap maps. This was great to edit GPS tracks and upload them to OSM for more data input. I am now trying to use my own maps. I have a collection of maps saved as png files (could convert to something else but I notice that viking uses png) and I would like to use them in a layer. Apparently, the map layer will only download maps from a server. However, the downloaded maps are saved locally so it must be possible to put my maps somewhere for viking to find them. However, I don't understand how the georeferencing is done, nor how the naming is done. I have googled and looked through documentation, but didn't find the answer. Anybody can point me in the right direction? Obviously, I hate doing that, as soon as posting I found it. GeoRef is the type. Still trying to understand what I need to specify, but I'll find it. After some playing around, I discovered a bug. The easting/northing that has to be provided seems to be for the top left corner, not top right as said by the tooltip. I also have slight differences compared to OSM data, but this can be due to many things, including not necessarily very good OSM data. Fred -- What Every C/C++ and Fortran developer Should Know! Read this article and learn how Intel has extended the reach of its next-generation tools to help Windows* and Linux* C/C++ and Fortran developers boost performance applications - including clusters. http://p.sf.net/sfu/intel-dev2devmay ___ Viking-devel mailing list Viking-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/viking-devel Viking home page: http://viking.sf.net/
Re: [Viking-devel] Using local maps: how?
On Fri, May 20, 2011 at 09:30:37PM +0100, Fred Labrosse wrote: On Friday 20 May 2011 21:03:56 Fred Labrosse wrote: Obviously, I hate doing that, as soon as posting I found it. GeoRef is the type. Still trying to understand what I need to specify, but I'll find it. If your maps aren't already georef'd, it's troublesome to find the correct values to use. For reference, the four values are: * meters per pixel in X direction * meters per pixel in Y direction * UTM X of top left map corner * UTM Y of top left map corner You'll note that there's no UTM zone. This doesn't matter on a small enough scale. I wrote a collection of scripts that triangulate the correct set of values from three lat/lon-x/y pairs, but they're nowhere near usable for the general public. If you're handy with maxima (the mathematica clone) let me know and I'll ship them your way. -- What Every C/C++ and Fortran developer Should Know! Read this article and learn how Intel has extended the reach of its next-generation tools to help Windows* and Linux* C/C++ and Fortran developers boost performance applications - including clusters. http://p.sf.net/sfu/intel-dev2devmay ___ Viking-devel mailing list Viking-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/viking-devel Viking home page: http://viking.sf.net/
Re: [Viking-devel] Using local maps: how?
On Fri, May 20, 2011 at 09:30:37PM +0100, Fred Labrosse wrote: On Friday 20 May 2011 21:03:56 Fred Labrosse wrote: Obviously, I hate doing that, as soon as posting I found it. GeoRef is the type. Still trying to understand what I need to specify, but I'll find it. If your maps aren't already georef'd, it's troublesome to find the correct values to use. For reference, the four values are: * meters per pixel in X direction * meters per pixel in Y direction * UTM X of top left map corner * UTM Y of top left map corner You'll note that there's no UTM zone. This doesn't matter on a small enough scale. I wrote a collection of scripts that triangulate the correct set of values from three lat/lon-x/y pairs, but they're nowhere near usable for the general public. If you're handy with maxima (the mathematica clone) let me know and I'll ship them your way. -- What Every C/C++ and Fortran developer Should Know! Read this article and learn how Intel has extended the reach of its next-generation tools to help Windows* and Linux* C/C++ and Fortran developers boost performance applications - including clusters. http://p.sf.net/sfu/intel-dev2devmay ___ Viking-devel mailing list Viking-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/viking-devel Viking home page: http://viking.sf.net/
Re: [Viking-devel] Using local maps: how?
On Friday 20 May 2011 22:44:30 you wrote: On Fri, May 20, 2011 at 09:30:37PM +0100, Fred Labrosse wrote: On Friday 20 May 2011 21:03:56 Fred Labrosse wrote: Obviously, I hate doing that, as soon as posting I found it. GeoRef is the type. Still trying to understand what I need to specify, but I'll find it. If your maps aren't already georef'd, it's troublesome to find the correct values to use. For reference, the four values are: * meters per pixel in X direction * meters per pixel in Y direction * UTM X of top left map corner * UTM Y of top left map corner You'll note that there's no UTM zone. This doesn't matter on a small enough scale. I wrote a collection of scripts that triangulate the correct set of values from three lat/lon-x/y pairs, but they're nowhere near usable for the general public. If you're handy with maxima (the mathematica clone) let me know and I'll ship them your way. Thanks for the offer. I have OS grid reference for all corners of all tiles so all I need to do is convert these to easting/northing. I can program in the usual languages so will probably end up doing it in C and some shell script... But I first need to find the equations. Cheers, Fred -- What Every C/C++ and Fortran developer Should Know! Read this article and learn how Intel has extended the reach of its next-generation tools to help Windows* and Linux* C/C++ and Fortran developers boost performance applications - including clusters. http://p.sf.net/sfu/intel-dev2devmay ___ Viking-devel mailing list Viking-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/viking-devel Viking home page: http://viking.sf.net/
Re: [Viking-devel] Using local maps: how?
But probably implies local adjustments? That would explain some discrepancies in scale I am seeing. In theory I should have 5 meters per pixel but end up having to say 7 for a better match. All these local adjustments will render my automation quite difficult. Ideally, I would like to cover an area that is roughly 250km x 250km... So probably viking converts lat/lon to UTM, and then just uses the georef map as if it is the right zone. I think what you need to do is to find the upper left pixel in WGS84 UTM. Check out the following program - probably viking should use it at some point, but it's the standard approach to coordinate conversion in the open source world: http://trac.osgeo.org/proj/ pgphE0QtBmJ7G.pgp Description: PGP signature -- What Every C/C++ and Fortran developer Should Know! Read this article and learn how Intel has extended the reach of its next-generation tools to help Windows* and Linux* C/C++ and Fortran developers boost performance applications - including clusters. http://p.sf.net/sfu/intel-dev2devmay___ Viking-devel mailing list Viking-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/viking-devel Viking home page: http://viking.sf.net/
Re: [Viking-devel] Using local maps: how?
On Fri, May 20, 2011 at 08:19:46PM -0400, Greg Troxel wrote: So probably viking converts lat/lon to UTM, and then just uses the georef map as if it is the right zone. Viking displays the map in every UTM zone. In practice this is rarely an issue since most people don't have maps that cover more than one zone. -- What Every C/C++ and Fortran developer Should Know! Read this article and learn how Intel has extended the reach of its next-generation tools to help Windows* and Linux* C/C++ and Fortran developers boost performance applications - including clusters. http://p.sf.net/sfu/intel-dev2devmay ___ Viking-devel mailing list Viking-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/viking-devel Viking home page: http://viking.sf.net/
Re: [Viking-devel] Using local maps: how?
Viking displays the map in every UTM zone. In practice this is rarely an issue since most people don't have maps that cover more than one zone. Probably true. USGS DRGs are free, so if I were more together I'd have more of them and would suffer aliasing. pgphz0eP2LW3p.pgp Description: PGP signature -- What Every C/C++ and Fortran developer Should Know! Read this article and learn how Intel has extended the reach of its next-generation tools to help Windows* and Linux* C/C++ and Fortran developers boost performance applications - including clusters. http://p.sf.net/sfu/intel-dev2devmay___ Viking-devel mailing list Viking-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/viking-devel Viking home page: http://viking.sf.net/
