How to implement multi-class semantic segmentation?
I'm able to train a U-net with labeled images that have a binary classification. But I'm having a hard time figuring out how to configure the final layers in Keras/Theano for multi-class classification (4 classes). I have 634 images and corresponding 634 masks that are unit8 and 64 x 64 pixels. My masks, instead of being black (0) and white (1), have color labeled objects in 3 categories plus background as follows: black (0), background red (1), object class 1 green (2), object class 2 yellow (3), object class 3 Before training runs, the array containing masks is one-hot encoded as follows: