I am using ArcGIS Pro 2.4.0, and am attempting to classify a field into a schema with three categories: Leaves, Shadows, and Soil. Here is a sample of the original RGB image:
Through supervised classification (SVM), I was able to create training samples and classify the image into the the desired categories:
Note: Green = leaves, black = shadows, brown = soil. Despite not having the accuracy statistics generated yet, it looks very accurate.
When I try to do the same thing with an unsupervised pixel-based classification (ISO is the only option on ArcGIS Pro that I am aware of), it will not let me divide it into three classes. Instead, it only gives me two:
The only setting I changed from the default ISO cluster settings was the maximum number of classes. I changed that from 5 to 3:
Does anybody know why this would happen? I don't have as much experience with unsupervised classifications as I do with supervised, so I'm not sure why I am not able to get 3 classes. Do I need to change some additional settings?