Raster Imagery Layer with Color Ramp on Image Server
What is the proper procedure for publishing a single band raster with values from about 0 to 700 as a referenced Imagery Layer on Image Server that has a default symbology of a color ramp for the raster values?
The resulting Imagery Layer needs to:
- Display with the color ramp symbology by default.
- When added to Pro, in Contents, show the color ramp and actual cell values in the legend.
- Respond to raster cell identification and return the actual cell value.
- Allow Portal based analysis that uses the actual cell value.
- Source data must be referenced, not hosted.
The symbology we have applied to the locally stored raster is:
The layer looks like this in Pro | Contents:
The raster is an Esri Grid. We have added the raster to a mosaic so that we can apply a Raster Function Template that will be referenced in the service. We have done this successfully for thematic rasters using attribute tables following this tutorial:
https://learn.arcgis.com/en/projects/share-raster-data-as-an-analytical-image-service/
Getting the symbology to work for a continuous raster, a DEM in this case, has proved difficult. Things we have tried for Raster Functions:
Just a Colormap. Colormap has Color Scheme Type: Color Ramp, Color Ramp: first option (this is the desired color ramp). The cell values identify to the actual cell value but only the values from 0 to 255 are symbolized. When published, the legend looks good, but again, only values from 0 to 255 symbolize.
Stretch and then Colormap. Stretch has Type: MinMax, Output Minimum: 0, Output Maximum: 255. Colormap has Color Scheme Type: Color Ramp, Color Ramp: first option. This symbolizes with the desired color ramp and all values are shown, but the actual cell value is not shown in the legend or by the identify tool. The values are remapped from 0 to 255. Same results when published.
Export as raster function template. In the symbology tab for the original locally stored raster, click the hamburger then “Export as raster function template.” Import the rft.xml file into Manage Processing Templates for the mosaic to be referenced by the service. This symbolizes the raster correctly but the identify tool returns the value as r,g,b and the legend shows RGB values, not the actual values and color ramp. Same results when published.
