I'm trying to make the difference between two DEM in an overlap area.
Already how do I create the overlap area of the two DEM (raster) in FME.
And how do I calculate the difference in pixel value height between raster 1 and raster 2?
thanks you!
This can be done using the RasterExpressionEvaluator.
What do I put in the expression to get the elevation value of A minus that of B?
+60- 2938 replies
What do I put in the expression to get the elevation value of A minus that of B?
If the band is 0 then A[0]-B[0].
I attached a sample workspace.
+6- Contributor
- 18 replies
Hi @dona, like already suggested by @nielsgerrits the RasterExpressionEvaluator is the right transformer for this purpose. As an addition, however: please note that the RasterExperssionEvaluator requires two rasters with the same dimensions. Please see this thread for a sample workspace.
What do I put in the expression to get the elevation value of A minus that of B?
Thanks for the template but as I have two rasters that are not the same the function is not good. My two rasters are in two different files and what I want is to calculate the difference in elevation of the two rasters in the overlapping area.
Hi @dona, like already suggested by @nielsgerrits the RasterExpressionEvaluator is the right transformer for this purpose. As an addition, however: please note that the RasterExperssionEvaluator requires two rasters with the same dimensions. Please see this thread for a sample workspace.
Hi @maayke,
Indeed, I had found this post before asking my question but I can't use the RasterExpressionEvaluator transformers only on the overlap area because I will have two rasters of the same dimension in the overlap area. Do you know how to extract the overlap area between the two rasters so that I have the same dimension and use RasterExpressionEvaluator?