MapServer vs ImageServer - Equivalent methods to raster functions?

Question

I am new to working with a Map Service.  I am using this public dynamic map service: https://mapservices.weather.noaa.gov/raster/rest/services/snow/NOHRSC_Snow_Analysis/MapServer

Layer ID:3 of this service is a raster layer representing snow depth.  I am trying to understand if there are server side or client side functions that would allow me to only show areas based on a minimum and maximum snow depth range?  I'm more familiar with an image service where I would use raster functions like mask, remap, and colormap to accomplish this.

Honestly I think I may be misunderstanding the fundamental concept behind a map service.  Any help would be appreciated.

Sage_Wall · Answer

Sorry about that @KeenanStahl , I don't have a good answer for you.  Without a snow depth field and being just an image there isn't really a way to modify the visualization of this Map Service after it's been published.  All of the renderers rely on fields and values. I guess that's one advantage to publishing these kinds of layers as an Image Service, but you've got no control over that ☹️

KeenanStahl · Answer

Hi @DavidSolari ,

I would like to learn more about "substitute a renderer that hides the undesirable pixels".  This map service doesn't seem to have any fields that contain the snow depth data but perhaps I can read the pixel values of the raster layer.

KeenanStahl · Answer

Hi @Sage_Wall ,

I had looked into applying a renderer.  Unfortunately, I don't see any fields in any of the sublayers that contain the snow depth data represented in the raster layer.  Is their a renderer that can use the RGB values in the raster layer?