TransDEM Forum

Hi, for some reason I cannot seem to crop. I have a large DEM Map and only want a small portion, i've tried looking through the help but I cannot work out how to reduce the size of the DEM.

The scissors tool is used for cropping. Create either a rectangular mask or - new for cropping in TransDEM 2.1.3 - a bounded region of DEM control points. Select the scissors tool, click outside the mask or bounded region, confirm "outside" and let TransDEM process the DEM. Save your cropped DEM with a new name afterwards.

See also TransDEM main manual page 24 "Erasing DEM Points" (intro) and page 68 "Menu Item: Erase DEM Points".

The problem im having is removing the black area around the DEM as shown below:

That will be always done automatically once you save the cropped DEM to file.

You can also explicitly apply the "Crop DEM margins" function but this will not have a visual affect if raster maps are loaded on top of the DEM.


[Edit and off-topic]:
BTW, have a look at UK Ordnance Survey Land-Form Panorama 50m DEMs, as a replacement for SRTM 3 arc sec