Hi,
Can anyone please help me on how to normalize a set of greyscale images using FME ? (Transforming the scale range of radiometric values to the [0,1] interval)
thank you very much
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Normalizing greyscale images
Best answer by tomf
To normalise into [0,1] you can use the expression:
( x - x_min ) / (x_range)
so for your case:
- A RasterStatisticsCalculator to calculate min and range on Band 0
- Followed by a RasterExpressionEvaluator for one band, and use the expression:
(A[0]-@Value(A:band0.min))/@Value(A:band0.range)
This output from that is now normalised [0,1]
+14- Contributor
- Best Answer
To normalise into [0,1] you can use the expression:
( x - x_min ) / (x_range)
so for your case:
- A RasterStatisticsCalculator to calculate min and range on Band 0
- Followed by a RasterExpressionEvaluator for one band, and use the expression:
(A[0]-@Value(A:band0.min))/@Value(A:band0.range)
This output from that is now normalised [0,1]
+14- Contributor
tomf wrote:
To normalise into [0,1] you can use the expression:
( x - x_min ) / (x_range)
so for your case:
- A RasterStatisticsCalculator to calculate min and range on Band 0
- Followed by a RasterExpressionEvaluator for one band, and use the expression:
(A[0]-@Value(A:band0.min))/@Value(A:band0.range)
This output from that is now normalised [0,1]
In detail:
Set the RasterStatisticsCalculator:
Then open the the Arithmetic Editor in the RasterExpresionEvaluator from the drop down menu on the right of the Expression column:
And finally create the expression for raster A band 0 (single raster, greyscale):
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