[Qgis-user] raster stats

[Tim Sutton]

Hi

On Sat, Nov 19, 2011 at 8:57 PM, John Callahan <john.callahan at udel.edu> wrote:
> Does anyone has information on the progress of this ticket?  From reading
> the comments on the the ticket, it looks as though there are some
> possibilities for enhancement.
> I use rasters regularly so this issue comes quite often.  For one particular
> 10GB DEM (in IMG format) it takes 7 or 8 minutes to calculate stats in QGIS,
> which takes a while when it happens every time I open that file.  Stats have
> already been computed through gdalinfo.  Thanks for any information.
> - John
>

This should no longer be an issue with recent changes I made. Please see:

http://hub.qgis.org/issues/3735

If you still get the issue, please let me know with detailed steps on
how to replicate.

Thanks

Tim


>
>
>
> On Thu, Apr 14, 2011 at 7:24 AM, Radim Blazek <radim.blazek at gmail.com>
> wrote:
>>
>> New ticket http://trac.osgeo.org/qgis/ticket/3735
>>
>> Radim
>>
>> On Mon, Mar 21, 2011 at 4:37 PM, John Callahan <john.callahan at udel.edu>
>> wrote:
>> > I'm not sure if this behavior is expected or I am missing something.
>> >
>> > I have a 1 band raster dataset (an elevation DEM) in TIF format.  It has
>> > statistics computed from "gdalinfo -stats mydata.tif"   However, when I
>> > open
>> > it in QGIS (both 1.6 and 1.7 trunk), and look at the Metadata tab in
>> > Layer
>> > properties, there are two sections that contain band stats information.
>> > The
>> > first section is labeled "Band 1" and lists the same stats as found
>> > using
>> > gdalinfo.  The second section is labeled "Band" and says "No stats
>> > collected
>> > yet" for band 1.  QGIS has to create the stats when I apply a color map
>> > or
>> > stretch.  For large rasters, this takes a while, and must be done each
>> > time
>> > it's used in QGIS.
>> >
>> > Has anyone experienced this behavior?  Is this expected?  Is there a way
>> > to
>> > let gdal compute all the stats that QGIS needs?  Thanks.
>> >
>> > - John
>> >
>> > **************************************************
>> > John Callahan, Research Scientist
>> > Delaware Geological Survey, University of Delaware
>> > URL: http://www.dgs.udel.edu
>> > **************************************************
>> >
>> > _______________________________________________
>> > Qgis-user mailing list
>> > Qgis-user at lists.osgeo.org
>> > http://lists.osgeo.org/mailman/listinfo/qgis-user
>> >
>> >
>
>
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>



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