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Import compressed (LZW) Geotiff - offline

Question asked by MM_GIS on Mar 17, 2016
Latest reply on Mar 17, 2016 by rscheitlin

Hi there,

I'm a developer in a web map project.

I'm working on an offline Import-geotiff task, everything works great besides compressed files..

I am using a library that parses the file but can handle only uncompressed files and with Packbits compression.

That's how I did it: The library provides me the image location and creates a canvas element with the image, then I create a graphic where the image should be and with a symbol of the image and it's size. The symbol is made using jsonUtils when the url is canvas.toDataURL() (In that way the canvas gives us a dataURL of a .png so the browser can handle this). The size of the symbol is changes as the user zoom in/out.

My questions are:

  1. Most of the tiff/tif images we work with are compressed with the LZW system, is there any way I can decompress the image before I start the process? Or any way I can parse the file?
  2. My solution with the symbol seems to be a little bit awkward, Is there any better way to do this?

 

If the above doesn't make sense - has anyone ever managed to import a tiff to a js client without using server side tools?

 

Thanks in advance, Ophir.

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