I've got an offline (local) map in case the online one fails. I get the local maps and I create a Geodatabase per each file, and then I create a FeatureLayer being the FeatureTable of the featurelayer the geodatabase. Finally I assign the LayerCollection of FeatureLayers to the BaseMap.BaseLayers.
My problem is that I need to adjust the contrast, gamma y brightness as with the WmtsLayer but I cannot. I've tried to cast the FeatureLayer to a Layer and then to ImageAdjustmentLayer but it returns and InvalidCastException.
How can I do this?