Poor Raster Rendering with Small Values (v100.4)

KeithGemeinhart1 — Sat, 11 Dec 2021 06:43:38 GMT

First, a general question about future versions of the runtime: Are there any plans to enhance the raster renderers or add a classify renderer?

More generally, I'm doing some raster analysis and adding them to the map by creating a RasterLayer with the file path:

var rlayer = new RasterLayer(path);
rlayer.Id = id;
rlayer.Renderer = RendererFactory.GenerateRenderer(product, path);
rlayer.Opacity = 0.6;
rlayer.IsVisible = false;
layers.Add(rlayer);‍‍‍‍‍‍

RendererFactory is a class I wrote that chooses the renderer properties based on the type of file. The problem I'm running into is that even when I set the renderer properties to match the symbology in Pro, often times it doesn't render or has a very narrow range of colors. Anecdotally, this seems more likely to happen when the raster values are small (<1), or have a small range, or a small number of unique values. But I haven't really tried to narrow it down.

This is an example of one my rasters in Pro:

Here is it's corresponding symbology:

The same raster rendered on my map looks like this:

Here are the rendering parameters:

IEnumerable<double> myGammaValues = new List<double>() { 1.0 };

var std = new StandardDeviationStretchParameters(2.0);
var numColors = Math.Ceiling(max - min);
if (numColors < 16)
 numColors = 16;
ColorRamp myColorRamp = ColorRamp.Create(PresetColorRampType.Elevation, (uint)numColors);

var rendrr = new StretchRenderer(std, myGammaValues, true, myColorRamp);
return rendrr;‍‍‍‍‍‍‍‍‍‍

The result is the same if I change color ramp to DemScreen or if I use Min/Max parameters for the stretch renderer.

However, if I set the layer renderer to null, I actually get a better rendering (albeit grayscale):

Any advice on how to improve my raster rendering????

P.S. Sample raster attached.

topic Poor Raster Rendering with Small Values (v100.4) in .NET Maps SDK Questions

Poor Raster Rendering with Small Values (v100.4)