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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?


6

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 ...


6

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 ...


5

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


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 ...


4

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 ...


4

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, ...


4

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

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.


3

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 ...


3

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.


3

If you find any version of GDAL which is built with ECW SDK version 3.x you can compress images up to 500 MB file size without a license. See http://www.gdal.org/frmt_ecw.html : "For those still using the ECW 3.3 SDK, images less than 500MB may be compressed for free, while larger images require licensing from ERDAS." You can check if GDAL is compiled with ...


2

1.- Install Homebrew 2.- Download the ECW/JP2 SDK from ERDAS and install on /usr/local 3.- Install gdal using formula: brew install gdal --enable-unsupported --complete Enjoy. By the way, if in addition you want other things like filegdb, the steps are similar (i.e step 2.5 would be to download and install the filegdb SDK to /usr/local) To ...


2

As is evident from your file sizes, the ECW files are compressed while Geotiffs do not seem to be (though, I believe geotiffs support compression). If you are only using the images as a background on maps, I recommend using the ECW because of their size. As you mentioned, since you are using them for change detection there may be artifacts in the ...


2

You probably have to install the ecw plugin from Erdas. Perhaps you did that for 1.7.4? Erdas will ask for your details but it is no problem. Depends on how you installed qgis, see Quantum GIS and ECW images?


2

This was said to work (on the mailing list http://osgeo-org.1560.n6.nabble.com/RE-ECW-td4646269i20.html#a5040712): from this archive (http://goo.gl/XiG21) copy gdal_ECW_JP2ECW into C:\OSGeo4W\bin\gdalplugins\1.9 directory. copy all other dll of previous archive in C:\OSGeo4W\bin and C:\Windows\System32 directories


2

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.


2

ERROR 2: C:\Users\agmartin\Desktop\google_maps_20.xml, band 1: Out of memory in InitBlockInfo(). ERROR 2: C:\Users\agmartin\Desktop\google_maps_20.xml, band 1: Out of memory in InitBlockInfo(). it sounds to me like a windows problem. Some time ago I did a png to geotiff conversion with GDAL (installed in linux), but the data were stored on windows (I have ...


2

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 ...


2

It's highly inefficient to merge mosaic using gdal merge. Instead, make a VRT (Virtual Dataset) and convert it to your favourite format.


2

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 ...


2

Getting into Raster processing with GDAL is a very effective place to start and this tutorial on Geoprocessing with Python using Open Source GIS is great if a little old. The first few lessons are on Vector data but you get to the Raster soon enough. Also, reading the ESRI documentation on raster data is very informative about processing methods and ...


2

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 ...


2

It works in a similar way than tileindex with geotiffs. Actually I would recommend to test first with a geotiff tileindex and couple of images so that you know that everything else despite ECW is configured correctly. If changing to ECW breaks something you know where to start searching the reason for the issue. It can be that the GDAL of your Mapserver does ...


2

Few years ago I did the same job very successfully with AU ECW Compressor (I've merged 49 ECWs or 7x7, into one ECW). It's free, also it's a very small program and easy to use. You could also make/save settings as scripts and run it later. http://www.advisory-unit.org.uk/site/aegis3/aegis_ecw.html The Free Advisory Unit ECW Compressor is a simple ...


2

Manually save a layer file of the raster in the r g b format. Then, use the same code as you did, but reference the saved .lyr file instead.


1

IMHO the best tutorials I know about this matter are: the GDAL Raster Formats about raster formats, where you can find a very exhaustive description of the most used raster formats, their creation option and various hidden properties; the GDAL utilities about raster manipulation. These are a very good starting point.


1

If you are up for some Esri training, they have a number of Virtual Campus courses available that deal with rasters. The search link is included below. Some you might start off with could be: Basics of Raster Data Displaying Raster Data Using ArcGIS Working With Rasters in ArcGIS Desktop ...


1

UPDATE: Here's a nice post from faunalia describing a step-by-step guide on how to add ECW support in windows (for gdal-1.9.2): http://www.faunalia.pt/node/438 If you've added the ubuntugis-unstable repository you can add ecw support by installing the corresponding library: $ sudo apt-get install libgdal-ecw To add the ubuntugis repository: sudo ...


1

By default QGIS doesn't support .ecw format (Compressed Satellite Imagery).For ECW support you need to download ecw plugin for QGIS for mac and to do it on Ubuntu you can follow instructions on http://lists.osgeo.org/pipermail/qgis-user/2010-May/008647.html I hope it will help.



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