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10

Quantum GIS now supports this feature, the resolution can be set and can include an optional world file containing georeferencing information. In the print composer check the "World file on" box under Export settings.


9

By now, ubuntugis-unstable has added trusty packages for QGIS 2.2 and GDAL 1.11. Unfortunately, libgdal-ecw-src is still missing, and the available versions for raring and precise are intended for GDAL 1.10. However, I got it working (with some help from the qgis user mailing list): Add ubuntugis-unstable for trusty to the sources list, or Ubuntu Software ...


9

Get the ECW-Plugin from here: KyngChaos (scroll to the middle of the page)


8

ECW libraries are not open source software and cannot be freely distributed. You need to add manually the ecw support in your local copy of gdal. On ubuntu do this: wget http://de-mirror.org/distro/gentoo/distfiles/libecwj2-3.3-2006-09-06.zip unzip libecwj2-3.3-2006-09-06.zip cd libecwj2-3.3 ./configure make sudo make install sudo gdal-ecw-build /usr/local/ ...


8

Based on huckfinn answers, few other comments and together with my findings: Winning format is JPEG2000 (why and which version is mentioned below Why not others) Why not others: JPEG Size limitation both data size and dimensions (4GB and 65500x65500) no (internal) pyramids possibility = bigger the image the longer it takes to display it when pan/zoom in/ ...


7

The Intergraph ECW JPEG2000 SDK v5.0 has been released and includes linux support. The ubuntugis-unstable ppa has been updated to include SDK v5.0 support in libgdal-ecw-src. Notes: As at 27 July 2013 build fails on 32bit Ubuntu ECW/JP2ECW drivers fail using Python bindings, gdal executables work fine. This SDK is licensed for Desktop use only and has ...


7

I ran an experiment with a TIFF file and an ECW. Started with a 1.2 GB ECW, and converted it to TIFF with compression and pyramids, it was ~1.5 GB. So I think that a TIFF can be a similar size to an ECW. I would mosaic the image using GDAL, ensuring that compression is on. Then build pyramids, and if the resulting file is reasonable (less than 10 GB, I ...


7

I had a similar problem few weeks ago . I resolved it this way: creating pyramids rasters image (all rasters had got pyramids depends on standard scale rate in my project creating tiles from raster (mosaic) putting all files to postgis (by WKTRaster) By this way you get MRDB (multi-resolution data base) which is the most effective way of serving a large ...


7

If you save the map canvas to a tif file, it will automagically be georeferenced. (A new, amazing feature in QGIS...). The resolution however will be the computer screen resolution. (96 dpi). So probably no more than 1900X1200 pixels.


7

See this ESRI KB article on publishing ECWs to ArcGIS Server - it requires special (extra) licensing from ERDAS. This may be your issue. Also, are you able to publish any map service?


7

Since 10.1, you can use the image analysis tools (Windows > image analysis) to create a mask function that will perform the masking on the fly Using the Mask function, you will specify one or more NoData values or a range of valid pixel values. The inputs for this function are the following: Input Raster / NoData Interpretation / NoData Values ...


6

For topic 2: Here is an longer investigation of JP2, because I was also interested, to use a more efficient compression. And the result IMO is: Within GDAL/QGIS (as a QgsRastrerDataProvider) you can't combine proper jpeg2000 compression and fast caching options like tile sets and block structures in a simple way. Normally I perfer GeoTiff for Raster-DB's, ...


5

You can cut it directly with gdal's tool gdal_translate if you know the coordinates of your Area of Interest, if its georeferenced: gdal_translate -projwin [ulx uly lrx lry] infile outfile If not use the -srswin flag like this: gdal_translate -srcwin [xoff yoff xsize ysize] infile outfile. Another option is to build a 'virtual' raster (of a few ...


5

Other ideas you could try: gdal_translate with the -srcwin switch gdalwarp with -cutline and -crop_to_cutline and -wm switches. The last one specifies memory for caching and may get you over the issues you had using clipper in QGIS (as this is essentially the same function) QGIS raster calculator setting the extent to the area you want (simpler than ...


5

You will need a paid Licence of the ERDAS SDK as the free (gratis) SDK is read-only. As an alternative try the Geotiff format with JPG compression. For example, using the following two commands (but you have GUIs in QGIS, for example) to convert ECWs to TIFFs you get rasters that are more or less 30% bigger than then ECWs but look the same and are also as ...


5

For topic 1. QGIS uses GDAL as an QgsRasterdataProvider. So the capabilities of reading and writing a raster format is implemented by the GDAL lib. You can find supported a format under the following link http://www.gdal.org/formats_list.html. The command gdal-config --formats gives you an overview which format stuff is build into your lib or edition. What ...


4

Save a complete QGIS project, rasters and vectors, to a high-resolution GeoTIFF? I don't think you can do this (at present). What you can do is export high-res images from the print composer and then georeference them. See this feature request: http://hub.qgis.org/issues/5840 Nick.


4

GDAL (and therefore QGIS) can only read ECW files. ECW is a proprietary file format, and one needs to buy the ERDAS-ECW-JP2 SDK to be able to write files. More details here.


4

This is an edited form of the solution that the OP had put in the Question Note: The QGIS 64bit installer used GDAL 1.10 which has the ECW plugin included. The 32bit installer is getting updated to GDAL 1.10 with the plugin at some stage, no ETA at the moment. The following method is only needed for the 32bit installer until it updated with the new GDAL. ...


4

The simplest way I can think of is to take the merged raster you have just made and save out the red band (perhaps using gdal_translate and the -b switch). Alternatively you could use QGIS' raster calculator to save only the red band as a new raster.


4

If QGIS is compiled against GDAL 1.10, you can't do much about it. So you have to downgrade the ecw driver to 1.10 to make them work together. See also these tickets: http://trac.osgeo.org/osgeo4w/ticket/417 http://hub.qgis.org/issues/10175 The issue might be solved with QGIS 2.4, which is just around the corner. In the setup.exe of OSGEO4W64, select ...


4

See here: http://www.kyngchaos.com/software/frameworks#gdal_complete you will need to install a "plugin" and then add (compiling I guess) the support into GDAL (using the SDK you MUST download from ERDAS, after accepting their license). For Linux the SDK is no more available (in the ERDAS site), and I don't remember to have seen something for OsX recently.


4

This problem is addressed in part by http://blog.hexagongeospatial.com/help-ecw-speckled-edges/ The only way to achieve consistent background color values after compression is by using an AllOpacity band which doesn't appear to be supported by the version of ECWJP2 SDK used in FME.


4

ECW file support is not included by default due to licensing issues. There is a tutorial for adding ECW support to QGIS on Ubuntu Linux. See here: https://faunaliagis.wordpress.com/2013/08/15/adding-ecw-support-in-qgis/ Basically you need to build lib-gdal-ecw and download an appropriate SDK.


4

You need to download QGIS 2.14.3 from OSGEO4W in order to be able to open ECW file format. The QGIS help stated that clearly. Also, here is a good source on ADDING ECW SUPPORT IN QGIS. The help provides good information on how to open ECW file format using different operating system.


4

0.017453292519943295 is the conversion factor from radians to decimal degrees, exactly PI()/180. Geodetic functions usually expect angles in radians, but our surveying ancestors decided to use degrees, minutes and seconds.


3

Your tilelevel 20 is very high. Set it to 18, your resulting files will be 4x smaller, so you will probably not run out of memory. Zoomlevel 20 is beyond what you see in a normal google maps web viewer (which zooms up to 19). All detail is visible at 18. All of this apart from the fact that this is not allowed by google.


3

I resolved the problem by applying MapServer's Shp2img.exe repeaetadly. MapServer is able to render a qGis project, if the project gets first exported by the standard MapServer plugin to a *.map file. Subsequently it is possible to render the project to a image file (png, jpg, tif). Unfortunately there is a limit of - lets say more or less - 10000*10000 ...


3

If you have the output_image.tif yet, you can follow the advice of @MappaGnosis, i.e.: gdal_translate -b 1 output_image.tif output_red.tif Alternatively, it's possible to extract the red band while building a VRT mosaic with gdalbuildvrt and then translate from VRT to GTIFF format: gdalbuildvrt -input_file_list c:\temp\rasterlist.txt -b 1 output_red.vrt ...


3

If you are using the ECW 4.x driver package, this is expected behaviour. From http://www.gdal.org/frmt_ecw.html The ECW 4.x SDK from ERDAS is only free for image decompression. To compress images it is necessary to build with the read/write SDK and to provide an OEM licensing key at runtime which may be purchased from ERDAS. Options are ECW 3.3 ...


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