from monai.networks.nets import UNet # unet model from monai (there are other models that you use with a single line)
model = UNet(
spatial_dims=2,
in_channels=3,
out_channels=1,
channels=[16, 32, 64, 128, 256, 512], # Number of channels at each layer during contraction
strides=(2, 2, 2, 2, 2), # Strides for the convolutional layers
num_res_units=4, # Number of residual units
dropout=0.15, # Dropout rate to prevent overfitting
)