I'm working on a undergraduate project with using deep learning. Currently, I'm trying to improve a model by modifying it. Model is Double U-Net and dataset that I'm using is DRIVE dataset. It consists from 20 images. My problem is validation score does not increase anymore. I think there is a overfit problem and also, I heard that is the max potential of network so I should try another dataset or model. Data separated 80% training and %10 validation. How can I improve result?
What I tried:
-Added one more U-Net network
-Using (128, 64, 32, 16) filter size
-Using (64, 32, 16, 8) filter size
-BinaryCrossEntropy loss function
-Added dropout exit of encoders with 0.5 value
-Added top, left, right and bottom symmetry augmentation for images, so total number of augmentation is 25
Augmentations (left-top is original image):
Results: