keras model summary:
Model: "sequential_1"
_________________________________________________________________
Layer (type)                 Output Shape              Param #
=================================================================
conv2d_3 (Conv2D)            (None, 256, 256, 32)      896
_________________________________________________________________
max_pooling2d_3 (MaxPooling2 (None, 128, 128, 32)      0
_________________________________________________________________
dropout_4 (Dropout)          (None, 128, 128, 32)      0
_________________________________________________________________
conv2d_4 (Conv2D)            (None, 128, 128, 64)      18496
_________________________________________________________________
max_pooling2d_4 (MaxPooling2 (None, 64, 64, 64)        0
_________________________________________________________________
dropout_5 (Dropout)          (None, 64, 64, 64)        0
_________________________________________________________________
conv2d_5 (Conv2D)            (None, 64, 64, 128)       73856
_________________________________________________________________
max_pooling2d_5 (MaxPooling2 (None, 32, 32, 128)       0
_________________________________________________________________
dropout_6 (Dropout)          (None, 32, 32, 128)       0
_________________________________________________________________
flatten_1 (Flatten)          (None, 131072)            0
_________________________________________________________________
dense_2 (Dense)              (None, 128)               16777344
_________________________________________________________________
dropout_7 (Dropout)          (None, 128)               0
_________________________________________________________________
dense_3 (Dense)              (None, 1)                 129
=================================================================
Total params: 16,870,721
Trainable params: 16,870,721
Non-trainable params: 0
_________________________________________________________________