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hariasa

Converting WMS data to Raster files

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Hi,

 

I want to convert data from a WMS (all aerial photos) to offline rasters. Is this possible? Sure you can load WMS directly in your GIS application, but this is not suitable for an internet connection as slow as mine. 

 

Programming examples would be very helpful.

 

Thanks  :)

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Hi,

 

I want to convert data from a WMS (all aerial photos) to offline rasters. Is this possible? Sure you can load WMS directly in your GIS application, but this is not suitable for an internet connection as slow as mine. 

 

Programming examples would be very helpful.

 

Thanks  :)

Hi!

 

I've done it. I've some WMS addresses, and i'm using Global Mapper 14 to download the rasters. You can easily download too, just install Gm14, then run it, there is and option in the start display, that "download from online sources", click on it, you will find some pre define online sources, but you can setup a new WMS or any type internet sources. If you configured your wms server, you just connect to it. If you want to export (download the data and export) to a new file, with any format type, you can click on file > export > raster > select the type and other things (resolution etc.). Then OK, and you need to wait, because even if you have very fast connection, maybe the GM + your computer will compute a bit. My advice, that you need a pre created shapefile, which can be use as mask to export the big online raster to smaller sections. Just open the shapefile in the GM14 too, and select one of these sections, and in the control panel you need to click on the raster > options > cropping > crop to current selected polygon. Now you need to hide the shapefile, and you can see your cropped image. Now export as i've wrote above:) Enjoy!

My advice, use ECW format. Small, very usable and the GIS programs eating it:))

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Hi!

 

I've done it. I've some WMS addresses, and i'm using Global Mapper 14 to download the rasters. You can easily download too, just install Gm14, then run it, there is and option in the start display, that "download from online sources", click on it, you will find some pre define online sources, but you can setup a new WMS or any type internet sources. If you configured your wms server, you just connect to it. If you want to export (download the data and export) to a new file, with any format type, you can click on file > export > raster > select the type and other things (resolution etc.). Then OK, and you need to wait, because even if you have very fast connection, maybe the GM + your computer will compute a bit. My advice, that you need a pre created shapefile, which can be use as mask to export the big online raster to smaller sections. Just open the shapefile in the GM14 too, and select one of these sections, and in the control panel you need to click on the raster > options > cropping > crop to current selected polygon. Now you need to hide the shapefile, and you can see your cropped image. Now export as i've wrote above:) Enjoy!

My advice, use ECW format. Small, very usable and the GIS programs eating it:))

 

I have tried this with GM 15, and it downloads the data, but it only creates blank rasters

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Hariasa... It works fine with GM15. First assure you're within the bounds of the imagery. Then create a rectangular area of the zone you want to download and proceed just as maunaloa says. Keep in mind the scale... The reason you get blank raster may be that you're downloading it outside the range (which are sadly not specified in the WMS server capabilities document)... I've successfully downloaded reasonably large datasets from 1:3000 to 1:20000 scales on you server.

Also note that the server is VERY slow, be patient.

 

The bbox is :

<LatLonBoundingBox minx="114.05291837045" miny="34.073413" maxx="123.42445031055" maxy="38.692566"/>

One tip would be if you don't already have shapefiles, use a World data (built in open street map based raster layer) to define the zone you want to download... Draw a rectangular area over the zone and select it, then zoom to the desired scale (the scale you want your raster layer to be exported). Then export raster. In the options click on "Click here to calculate spacing in other units..." it opens a window, click on "Use current screen pixel size" and then "OK". Untick "Save vector data if displayed" if you don't want your rectangular area to appear. (If you do have vectors to export over the raster, leave the box ticked but hide the layer containing the rectangular area before exporting).

 

One last thing, leave the projections by default (EPSG:4326)... I've tried with Gauss Kruger settings but it didn't work, best to download the raster in the native projection and then reproject it, i've tried with the city of Jinan for example, raster at 1:3000 scale (in EPSG:4326) and then reprojected to 3° Gauss Kruger (New Beijing CM 117E, EPSG:4796) which gave a nice image of 10000 x 5400 px at 78cm per pixel. So everything works fine.

 

If it's not clear enough, ask.

Cheers.

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