I have a map service that contains a SDE raster layer and served out by ArcGIS Server 10.1. Is it possible and how to query through REST service on the raster layer? Basically what I want to do is to query the pixel value for the given x, y coordinates. Didn't find any example to do it.
You can use the Identify Operation on the Mapservice to get the pixel values from the raster.
Using the Identify Operation on a map service with Rasters, I can get both the Pixel value, as well as the stretched values:
If you want more control over the request that the Identify tool does. You can monitor your network traffic (for example with Google Chrome if you do the identify from the browser) and see the request that is sent to your service when an Identify is done.