+44Hello Team,
My customer has a source data and the goal is extract just a yellow line from it.The problem is when i use the transformer ( RasterCellCoercer ) after my source data the time and performance to get the polygons is not good.
I believe the transformer RasterExpressionEvaluator is a right solution to find these values RGB
Attachment my template file.
Thanks in Advance,
Danilo de Lima
+28Converting from raster to vector in FME is notoriously slow.
You are on the right track for ways to improve performance. If you use the RasterExpressionEvaluator to create a 1 band image where your yellow RGB value(s) have a value of 1, and everything else 0, and then set the Nodata Value to 0 (RasterBandNoDataSetter) then the coersion should be more efficient.
You can also experiment to see of the RasterExtentsCoercer (DataExtents) or RasterToPolygonCoercer is more efficient than the RasterCellCoercer for your particular data.
+17Hi @danilo_inovacao Yep you will see a vast improvement in perforamnce if you do as @jdh suggests. For your particular case you can use this expression in the RasterExpressionEvaluator (use Int8 as the
interpretation):
@if(A[0]==255 && A[1]==251 && A[2]==134,1,0)
Follow this with a RasterBandNoDataSetter to set 0 = NoData and then a RasterToPolygonCoercer to get it into vectors and Bob's your uncle! The process shouldn't take any longer than 5 seconds!
The output should be a line or a polygon?
Anyway, I have experienced that a 'Generalizer' after this raster-to-vector conversion can be helpful in further processing. Just saying!
+44Converting from raster to vector in FME is notoriously slow.
You are on the right track for ways to improve performance. If you use the RasterExpressionEvaluator to create a 1 band image where your yellow RGB value(s) have a value of 1, and everything else 0, and then set the Nodata Value to 0 (RasterBandNoDataSetter) then the coersion should be more efficient.
You can also experiment to see of the RasterExtentsCoercer (DataExtents) or RasterToPolygonCoercer is more efficient than the RasterCellCoercer for your particular data.
+44The output should be a line or a polygon?
Anyway, I have experienced that a 'Generalizer' after this raster-to-vector conversion can be helpful in further processing. Just saying!
Thanks your help :)
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