Hi On Wed, Jun 8, 2011 at 9:21 PM, Mingjie Su <su.m...@geoeye.com> wrote: > All- > We are making some good progress on the ossim image provider > (qgsossimprovider.cpp). Couple questions: > > (1) Is there a way for users to specify which provider to use? It looks like > QGIS is hard coded to use the GDAL provider. > > (2) Band statistics. QGIS is pretty inefficient when it comes to computing > band statistics. Its looping through all the pixels multiple times (once for > each band) to populate the viewport. For RGB data for example, its looping > through the data 3 times. In OSSIM, we can provide the band statistics for > you so you don't have to scan the data. This will speed things up > dramatically. BTW, this is true for both the GDAL and OSSIM providers. >
This is a known issue. I have a branch where I have been replacing the stats routines to use native stats from providers. You can clone it from here: https://github.com/timlinux/Quantum-GIS/tree/raster-stats Its still unstable but maybe you can see where I am heading with this. > (3) Black pixels (0,0,0 RGB) are being flipped to transparent. Is there a way > to override this behavior programatically? > > (4) In OSSIM we have a concept of image chains and connectable objects. You > can wire up all kinds of filters and equations into a workflow to create an > output image. The image chain can be represented using an array of key value > pairs. Does the provider interface provide a mechanism for passing this type > of information? Currently not, but its an addition that we would love to see. The OTB folks would appreciate this too. > > (5) Can we post our ossim image provider to your svn for others to play with? > Since we are using GIT now, you can simply fork QGIS, apply your patches and invite others to test it out. I look forward to doing so myself. Regards Tim > > Thanks, > Ming > > > > -----Original Message----- > From: Peter Borissow > Sent: Wednesday, May 25, 2011 4:08 PM > To: Tim Sutton; Pirmin Kalberer > Cc: qgis-developer@lists.osgeo.org; qgis-os...@lists.sourceforge.net; Mingjie > Su; Harsh Govind > Subject: RE: [Qgis-developer] Integrating OSSIM with QGIS > > Hi Tim- > We are playing with 1.6. We'll download the 1.7 branch right away. I agree, > use of gdal should be abstracted away into a gdal provider. Sounds like we > would create an OSSIM provider. > > And yes, we want to create/execute OSSIM image chains directly in QGIS! > > Thanks, > Peter > > > > -----Original Message----- > From: Tim Sutton [mailto:li...@linfiniti.com] > Sent: Wednesday, May 25, 2011 4:03 PM > To: Pirmin Kalberer > Cc: qgis-developer@lists.osgeo.org; Peter Borissow; > qgis-os...@lists.sourceforge.net; Mingjie Su; Harsh Govind > Subject: Re: [Qgis-developer] Integrating OSSIM with QGIS > > Hi Peter > > 8<-------------------snip---------------------- > >>> > We started our investigation late last week. We have a debug version >>> > of QGIS up and running in Visual Studio 10 (64 bit) using QT 4.7.3. We >>> > have since discovered how integral GDAL is to QGIS. Undaunted, we >>> > added a some temporary hacks to bypass GDAL and we're now getting >>> > images to display via OSSIM! For us, this is a huge first step and we >>> > are seriously considering pressing ahead. > > What version are you building against? Since the 1.7 branch and in > current master branch, Radim Blazek has done a great overhaul to cater > for proper raster providers. That means you should not find QGIS is > heavily intertwined with GDAL - the use of gdal should be abstracted > away into the gdal provider, and you should be able to implement ossim > raster support as a clean separate provider. > > I would also really love to see OSSIM support in QGIS (and maybe some > of those nice processing chains making their way into QGIS :-). > > Regards > > Tim > > 8<-------------------snip---------------------- > -- > Tim Sutton - QGIS Project Steering Committee Member (Release Manager) > ============================================== > Please do not email me off-list with technical > support questions. Using the lists will gain > more exposure for your issues and the knowledge > surrounding your issue will be shared with all. > > Visit http://linfiniti.com to find out about: > * QGIS programming and support services > * Mapserver and PostGIS based hosting plans > * FOSS Consulting Services > Skype: timlinux > Irc: timlinux on #qgis at freenode.net > ============================================== > -- Tim Sutton - QGIS Project Steering Committee Member (Release Manager) ============================================== Please do not email me off-list with technical support questions. Using the lists will gain more exposure for your issues and the knowledge surrounding your issue will be shared with all. Visit http://linfiniti.com to find out about: * QGIS programming and support services * Mapserver and PostGIS based hosting plans * FOSS Consulting Services Skype: timlinux Irc: timlinux on #qgis at freenode.net ============================================== _______________________________________________ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
