Question

Is there a transformer to directly contour a raster file (geotiff format). Which also does not contour on empty raster cells?

  • 25 September 2017
  • 7 replies
  • 2 views

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7 replies

Userlevel 2
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Have you looked at the Contourgenerator transformer?

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Or RasterCellCoercer?

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Thank you for your suggestions. I tried the contourgenerator transformer. But this transformer creates contours over the area with nodata, which I don't want (see below image). Maybe I am doing something wrong, but I don't see the option to create a contour with the rastercellcoercer.

Userlevel 3
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You can create a polygon that covers the extents of the raster data using the RasterExtentsCoercer set to Data Extents mode. Then, use the Clipper to clip the contours to the polygon.

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Thank you cartoscro. This is what I was looking for.

 

 

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Thank you cartoscro. Your transformers work. The only problem I have is that they don't work for large raster files. 4.2 Mb works, 3.5Gb doesn't.

 

 

Userlevel 3
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3.5gb is a large file. Try the workflow below. Splitting the data into chunks may help it to run a little faster. This splits the raster into 4 datasets, but you may need to increase this number.

 

 

tiled-raster.jpg

 

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