[gdal-dev] Gdalinfo is missing documentation for -approx_stats
Hi, I was reading from Quantum GIS mailing list that there exists an -approx_stats option in gdalinfo utility but it is not documented in http://www.gdal.org/gdalinfo.html It looks like the author did not bother to report the issue here so I did even I do not know what is the purpose of this approx_stats thing. -Jukka Rahkonen- ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] Gdalinfo is missing documentation for -approx_stats
W dniu 2012-09-04 14:53, Jukka Rahkonen pisze: I was reading from Quantum GIS mailing list that there exists an -approx_stats option in gdalinfo utility but it is not documented in http://www.gdal.org/gdalinfo.html It looks like the author did not bother to report the issue here so I did even I do not know what is the purpose of this approx_stats thing. Here you go with purpose of it: http://www.gdal.org/classGDALRasterBand.html#a6aa58b6f0a0c17722b9bf763a96ff069 -approx_stats sets /bApproxOK as true. /Piotr / ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] How to cut a Raster map with a KML file
Thank you Chitanya. But it created an output file with two layers (one with the values from original file and another with a 255 for the pixels thar are inside KMZ file: How can I have just one layer? Other thing: as far as I saw it procewssed the data without needing to have the KML and the Geotiff in the same CRS. Can anyone confimr that this is true? Thanks Luis On Mon, Sep 3, 2012 at 5:10 PM, Chaitanya kumar CH chaitanya...@gmail.comwrote: Luis, gdalwarp has some options for this exact purpose. The cutline can be from any of the OGR readable datasource. http://www.gdal.org/gdalwarp.html On Mon, Sep 3, 2012 at 9:34 PM, Luis Lisboa luislisboa1...@gmail.comwrote: Greetings I have a raster file (Geotiff) and I have a KML file with a polygon and I want to cut raster map to only have valid values inside the polygon. How can I do this using just GDAL? Usually I used to cut geotiff file with gdalwarp and but in those cases I was cutting a square (xmin xmax ymin ymax) and in this case is a more complex polygon Thanks Regards, Luis ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev -- Best regards, Chaitanya kumar CH. +91-9494447584 17.2416N 80.1426E ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] Gdalinfo is missing documentation for -approx_stats
Jukka, The option -approx_stats is useful if you want less precise statistics in less time. Updated the dox in the revision 24905 and 24906. Thanks for the notice Jukka. On Tue, Sep 4, 2012 at 6:33 PM, Piotr Tracz pi...@cgis.pl wrote: W dniu 2012-09-04 14:53, Jukka Rahkonen pisze: I was reading from Quantum GIS mailing list that there exists an -approx_stats option in gdalinfo utility but it is not documented inhttp://www.gdal.org/gdalinfo.html It looks like the author did not bother to report the issue here so I did even I do not know what is the purpose of this approx_stats thing. Here you go with purpose of it: http://www.gdal.org/classGDALRasterBand.html#a6aa58b6f0a0c17722b9bf763a96ff069 -approx_stats sets *bApproxOK as true. /Piotr * ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev -- Best regards, Chaitanya kumar CH. +91-9494447584 17.2416N 80.1426E ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
[gdal-dev] Problems with OGRGeometry Intersects
Hi,
I'm using Gdal 1.9.
I have a function that has to perform a intersection of a geometry based on
the click that is made on the screen.
The raster file (Geotiff) that has a projected reference system (WGS 84 /
UTM zone 21S) and the geometry a georeferenced system (EPSG - 4326 WGS84).
The click that comes from the screen (spatial reference of the image)
create a geometry from calling point.Buffer (radius).
When i want to verify that the geometries intersect the intersects method
from OGRGeometry fails, even if the querypoint is transformed into the
spatial reference system of the geometry.
Envelopes from the 2 geometries.
QueryPoint
env.
if i generates the querypoint from the spatial reference of the geometry
that i want to intersect)
minx -61.66, maxx -53.66;
miny -41.97, maxy -33.97
else
minx 443322.50, maxx 443330.50
miny 5798153.59, maxy 5798161.59
Geometry env.
minx -57.79, maxx -57.59;
miny -38.08, maxy-37.92
The code is something like this:
// spatialfilterwindow image subset transformed into
// the spatial reference of the vector to intersect
Extent spatialfilter(spatialfilterwindow);
player-SetSpatialFilterRect(spatialfilter.min_.x_,
spatialfilter.min_.y_,
spatialfilter.max_.x_,
spatialfilter.max_.y_);
OGRLayer* player = ...;
OGRFeature *pfeature = player-GetNextFeature();
OGRPoint querypoint = OGRPoint(Point.x_, Point.y_);
querypoint.assignSpatialReference(new OGRSpatialReference(SrWkt.c_str()));
OGRGeometry* pquerypoly = querypoint.Buffer(radius);
*while *(pfeature) {
OGRGeometry *pgeometry = pfeature-GetGeometryRef();
*if *((pgeometry pgeometry-Intersects(pquerypoly) == TRUE)
|| (pquerypoly pquerypoly-Intersects(pgeometry) == TRUE)) {
// do something...
} *else *{
// handle the intersection fail
}
pfeature = player-GetNextFeature();
}
Any idea why it fails?
Thanks,
Regards,
--
Gabriel Fusca
SUR Emprendimientos Tecnológicos
Perú 345 Piso 5to Oficina B (C1067AAG)
Ciudad de Buenos Aires, Argentina
Tel. +54 (11) 4342-2976/84
gabrielfu...@suremptec.com.ar
http://www.suremptec.com/
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Re: [gdal-dev] Problems with OGRGeometry Intersects
Le mardi 04 septembre 2012 23:04:16, Gabriel Fusca a écrit :
Hi,
I'm using Gdal 1.9.
I have a function that has to perform a intersection of a geometry based on
the click that is made on the screen.
The raster file (Geotiff) that has a projected reference system (WGS 84 /
UTM zone 21S) and the geometry a georeferenced system (EPSG - 4326 WGS84).
The click that comes from the screen (spatial reference of the image)
create a geometry from calling point.Buffer (radius).
When i want to verify that the geometries intersect the intersects method
from OGRGeometry fails, even if the querypoint is transformed into the
spatial reference system of the geometry.
Envelopes from the 2 geometries.
QueryPoint
env.
if i generates the querypoint from the spatial reference of the geometry
that i want to intersect)
minx -61.66, maxx -53.66;
miny -41.97, maxy -33.97
else
minx 443322.50, maxx 443330.50
miny 5798153.59, maxy 5798161.59
Geometry env.
minx -57.79, maxx -57.59;
miny -38.08, maxy-37.92
The code is something like this:
// spatialfilterwindow image subset transformed into
// the spatial reference of the vector to intersect
Extent spatialfilter(spatialfilterwindow);
player-SetSpatialFilterRect(spatialfilter.min_.x_,
spatialfilter.min_.y_,
spatialfilter.max_.x_,
spatialfilter.max_.y_);
OGRLayer* player = ...;
OGRFeature *pfeature = player-GetNextFeature();
OGRPoint querypoint = OGRPoint(Point.x_, Point.y_);
querypoint.assignSpatialReference(new OGRSpatialReference(SrWkt.c_str()));
OGRGeometry* pquerypoly = querypoint.Buffer(radius);
*while *(pfeature) {
OGRGeometry *pgeometry = pfeature-GetGeometryRef();
*if *((pgeometry pgeometry-Intersects(pquerypoly) == TRUE)
|| (pquerypoly pquerypoly-Intersects(pgeometry) == TRUE)) {
// do something...
} *else *{
// handle the intersection fail
}
pfeature = player-GetNextFeature();
}
Any idea why it fails?
I suspect that you assumed assignSpatialReference() would do the reprojection,
which isn't the case (it just blindly assigns the specified SRS, but doesn't
alter the geometry coordinates). You must use the TransformTo() method
instead.
Incidental comment : you don't need to test ( A-Insersects(B) || B-
Insersects(A)). Intersects() is a symetrical operation, so just one test will
be enough.
Thanks,
Regards,
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