public sealed class RasterLayer : BasicRasterLayer, ArcGIS.Desktop.Core.IMetadataInfo, IMetadataSource, System.ComponentModel.INotifyPropertyChanged  

string url = @"C:\Images\Italy.tif";
await QueuedTask.Run(() =>
{
  // Create a raster layer using a path to an image.
  // Note: You can create a raster layer from a url, project item, or data connection.
  rasterLayer = LayerFactory.Instance.CreateLayer(new Uri(url), aMap) as RasterLayer;
});

// Create a new stretch colorizer definition using default constructor.
StretchColorizerDefinition stretchColorizerDef = new StretchColorizerDefinition();
var rasterLayerCreationParams = new RasterLayerCreationParams(new Uri(url))
{
  ColorizerDefinition = stretchColorizerDef,
  Name = layerName,
  MapMemberIndex = 0
};
await QueuedTask.Run(() =>
{
  // Create a raster layer using the colorizer definition created above.
  // Note: You can create a raster layer from a url, project item, or data connection.
  RasterLayer rasterLayerfromURL =
    LayerFactory.Instance.CreateLayer<RasterLayer>(rasterLayerCreationParams, aMap);
});

var raster = MapView.Active.Map.GetLayersAsFlattenedList().OfType<RasterLayer>().FirstOrDefault();
if (raster != null)
{
  await QueuedTask.Run(() =>
  {
    var rasterTbl = raster.GetRaster().GetAttributeTable();
    var cursor = rasterTbl.Search();
    while (cursor.MoveNext())
    {
      var row = cursor.Current;
    }
  });
}