[Qgis-user] Selecting rasters with vector layer

[Asher Kamiraze]

Eric,

I just tried to create a VRT from all ecw images in a folder.
Unfortunately, it does not work, the command line seems to be rejected when
there are too many input files. The problem also appear if directly using
the gdalbuildvrt from the command line. The only solution I found was to
build an input_file_list with the following command:

cd <to_my_ecw_folder>
dir /b *.ecw > listin_ecw.txt
gdalbuildvrt -input_file_list listin_ecw.txt all_ecw.vrt

Then, if I try to save the cropping result as an ECW file, I got the
following error:

Output driver `ECW' not recognised or does not support
direct output file creation. The following format drivers are configured
and support direct output:
GeoRaster: Oracle Spatial GeoRaster
VRT: Virtual Raster
GTiff: GeoTIFF
NITF: National Imagery Transmission Format
HFA: Erdas Imagine Images (.img)
ELAS: ELAS
MEM: In Memory Raster
BMP: MS Windows Device Independent Bitmap
PCIDSK: PCIDSK Database File
ILWIS: ILWIS Raster Map
SGI: SGI Image File Format 1.0
Leveller: Leveller heightfield
Terragen: Terragen heightfield
netCDF: Network Common Data Format
HDF4Image: HDF4 Dataset
ISIS2: USGS Astrogeology ISIS cube (Version 2)
ERS: ERMapper .ers Labelled
RMF: Raster Matrix Format
RST: Idrisi Raster A.1
INGR: Intergraph Raster
GSBG: Golden Software Binary Grid (.grd)
GS7BG: Golden Software 7 Binary Grid (.grd)
PNM: Portable Pixmap Format (netpbm)
ENVI: ENVI .hdr Labelled
EHdr: ESRI .hdr Labelled
PAux: PCI .aux Labelled
MFF: Vexcel MFF Raster
MFF2: Vexcel MFF2 (HKV) Raster
BT: VTP .bt (Binary Terrain) 1.3 Format
LAN: Erdas .LAN/.GIS
IDA: Image Data and Analysis
GTX: NOAA Vertical Datum .GTX
NTv2: NTv2 Datum Grid Shift
CTable2: CTable2 Datum Grid Shift
ADRG: ARC Digitized Raster Graphics
SAGA: SAGA GIS Binary Grid (.sdat)

The generated command line by QGIs is:

gdalwarp -q -cutline "F:\\MY_SHP_PATH\\Commune_Aix-en-Provence.shp"
-crop_to_cutline -of ECW F:\MY_VRT_PATH\Toutes_dalles_13.vrt
"F:/MY_OUTPUT_PATH/crop.ecw"

It does not seem to be a "\" "/" issue, since if I choose a .vrt output it
works fine.

Any idea on how to solve the problem?

I am running QGIS 2.2.0 on 64 bits windows.

Regards



2014-03-04 1:51 GMT+01:00 Eric Goddard <egoddard1010 at gmail.com>:

> Yes, you should be able to choose ECW from the files of type drop down in
> the output file selection dialog and select ECW.
>
> Eric
>
>
> On Mon, Mar 3, 2014 at 4:48 PM, Asher Kamiraze <asher.kamiraze at gmail.com>wrote:
>
>> Thanks Eric, sounds really good. Is there a way to save the resulting
>> file (clipped) as an ECW file? I need to process it later with a 3rd party
>> software.
>>
>> Regards
>>
>>
>> 2014-03-03 23:26 GMT+01:00 Eric Goddard <egoddard1010 at gmail.com>:
>>
>> Hi asher, if you go to raster -> miscellaneous, there is a menu entry
>>> called build virtual raster catalog. You can use that to virtually mosaic
>>> all of your ECW files. This tool creates a new file you can load in as a
>>> raster that references all of the individual ECW files to display them
>>> seamlessly in qgis without having to spend the time to actually mosaic all
>>> of them together. Load the resulting vrt file into qgis using add raster
>>> and clip the vrt to your polygon layer using raster -> extraction ->
>>> clipper.
>>>
>>> Eric
>>> On Mar 3, 2014 3:53 PM, "Asher Kamiraze" <asher.kamiraze at gmail.com>
>>> wrote:
>>>
>>>> Hi all,
>>>>
>>>> I have a set of more than 200 ecw rasters that I can easily load in
>>>> QGIS. I also have a vector polygon layer which bounds an area covering a
>>>> part of the area covered by the whole set of rasters. What I would like to
>>>> do is to extract only, the raster which are intersected by the vector
>>>> boundary. As a final goal, I would like to only mosaic thoses images. I did
>>>> not found a way to easily do this in QGIS. Any idea on how to achieve this?
>>>>
>>>> As a workaround, I have opened only the raster intersecting the vector,
>>>> and would like to mosaic them. However, it does not seem to be a function
>>>> in QGIS ready to mosaic all opened (or selected) rasters. Any idea on how
>>>> to automate the process?
>>>>
>>>> Hope you could help
>>>>
>>>> Regards
>>>>
>>>> _______________________________________________
>>>> Qgis-user mailing list
>>>> Qgis-user at lists.osgeo.org
>>>> http://lists.osgeo.org/mailman/listinfo/qgis-user
>>>>
>>>
>>
>
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