Using a raster function to set symbology

[Gianna_BBSRC]

Hi everyone, 

I'm trying to set the symbology on several hundred .tiff raster files. 

I need to customize the statistics and would like to symbolize using a stretch MinMax function on each raster. 

So I've set up the custom statistics in the raster function as below:

From there, I've tried every combination of using Stretch and ColorMap functions but the result ends up with a classified symbology ranging from 0-255

Any ideas?

[DanPatterson]

Are they singleband tiff files?

Are the data integer or floating point?

What are the expected min and max's?

Do all rasters cover basically the same min and max range?

[Gianna_BBSRC]

Hi Dan, 

Singe-band 32-bit floats

mins and maxes somewhere in the ranges from 0-1000 of different meteorological indicators 

rasters in sets of four cover the same min/max ranges, 420 maps total

[DanPatterson]

If you did it manually, and it is single band, float, I would have expected a gray scale image  ie a color ramp, then stretched

[Gianna_BBSRC]

Yep but I've set my Raster and Imagery defaults to a different colorramp, should have mentioned. It would typically default to grayscale, but still be classified instead of stretch

[DanPatterson]

Raster rendering behavior—ArcGIS Pro | Documentation

the default resampling method is bilinear and the default stretch is minimum-maximum.

That is why I wonder why you mention ColorMap instead of ColorRamp

[Gianna_BBSRC]

I refer to the ColorMap raster function, which has colorRamp as an option within it

I have found a workaround to this by attaching a processing template which calcs the statistics (and does nothing else) and then set the rendering defaults to my desired symbology within ArcGIS Pro. 

But I'm looking for a solution to this symbology issue with raster functions because I'd like to publish it as an image service and have the correct symbology already applied instead of using client-side rendering to change the vis (which is was I'm doing now in Esri JS API)

[AndrewRitchie_CoL]

Did you ever find a solution Giannalogy?

I'm trying to publish an image service, with a predefined stretch/colour ramp and came up with the same workflow.

I've built the Raster Function template, but cannot get the Colormap and Stretch tools to work together - so I end up with the classified raster, same as you.

[Gianna_BBSRC]

Hi Andrew,

No dice, I'm afraid. It seems like pretty buggy behaviour to me.

[AndrewRitchie_CoL]

Thanks. I can see that we are trying to apply two different visual functions, so they can't be chained. But the stretch function should allow you to apply a colour ramp.

It's also supposed to be possible from the Symbology tool:

But this method doesn't work for me either. It manages to apply the correct color ramp, but seems to now think it's an RGB raster, and I lose access to the original band data.

Time to lodge a case for this method - or try and hack the Raster Function xml 😕