I have created different CNNs for doing image classification.
The dataset is this: https://www.kaggle.com/crowww/a-large-scale-fish-dataset
There are 9 classes, and each class contains 1000 images of fish. I split in training (800 imgs per class), validation (100) and test (100).
I created different CNN with these layers:
1)1 convolutional layers (conv, relu, batchnorm) + 2 fully connected layers + output
2)2 convolutional layers (conv, relu, batchnorm and maxpooling) + 2 fully connected layers + output
3)4 convolutional layers (conv, relu, batchnorm and maxpooling) + 2 fully connected layers + output
These are the outputs of each model: 1):
Epoch 1: TrL=0.6311, TrA=0.8006, VL=0.2925, VA=0.9077, TeL=0.4005, TeA=0.8708, Epoch 2: TrL=0.0443, TrA=0.9939, VL=0.2072, VA=0.9235, TeL=0.3610, TeA=0.8896, Epoch 3: TrL=0.0156, TrA=0.9993, VL=0.2128, VA=0.9161, TeL=0.3231, TeA=0.8896, Epoch 4: TrL=0.0090, TrA=0.9996, VL=0.1883, VA=0.9287, TeL=0.2808, TeA=0.9000, Epoch 5: TrL=0.0058, TrA=1.0000, VL=0.1663, VA=0.9350, TeL=0.2689, TeA=0.8990, Epoch 6: TrL=0.0044, TrA=1.0000, VL=0.1628, VA=0.9339, TeL=0.2594, TeA=0.9073, Epoch 7: TrL=0.0035, TrA=1.0000, VL=0.1675, VA=0.9350, TeL=0.2662, TeA=0.9062, Epoch 8: TrL=0.0028, TrA=1.0000, VL=0.1608, VA=0.9350, TeL=0.2697, TeA=0.9031, Epoch 9: TrL=0.0024, TrA=1.0000, VL=0.1645, VA=0.9350, TeL=0.2688, TeA=0.9052, Epoch 10: TrL=0.0021, TrA=1.0000, VL=0.1556, VA=0.9339, TeL=0.2691, TeA=0.9073
Epoch 1: TrL=0.4261, TrA=0.8676, VL=0.2128, VA=0.9469, TeL=0.3264, TeA=0.8917, Epoch 2: TrL=0.0193, TrA=0.9982, VL=0.1412, VA=0.9719, TeL=0.2580, TeA=0.9094, Epoch 3: TrL=0.0060, TrA=1.0000, VL=0.1064, VA=0.9719, TeL=0.2463, TeA=0.9104, Epoch 4: TrL=0.0037, TrA=1.0000, VL=0.0811, VA=0.9802, TeL=0.2210, TeA=0.9177, Epoch 5: TrL=0.0025, TrA=1.0000, VL=0.0794, VA=0.9792, TeL=0.2098, TeA=0.9250, Epoch 6: TrL=0.0020, TrA=1.0000, VL=0.0768, VA=0.9792, TeL=0.2100, TeA=0.9260, Epoch 7: TrL=0.0016, TrA=1.0000, VL=0.0730, VA=0.9802, TeL=0.2025, TeA=0.9292, Epoch 8: TrL=0.0014, TrA=1.0000, VL=0.0720, VA=0.9792, TeL=0.2040, TeA=0.9292, Epoch 9: TrL=0.0012, TrA=1.0000, VL=0.0731, VA=0.9792, TeL=0.1927, TeA=0.9313, Epoch 10: TrL=0.0011, TrA=1.0000, VL=0.0696, VA=0.9792, TeL=0.2019, TeA=0.9292
Epoch 1: TrL=0.7956, TrA=0.7686, VL=0.8161, VA=0.6991, TeL=0.9512, TeA=0.6719, Epoch 2: TrL=0.0815, TrA=0.9894, VL=0.4978, VA=0.8254, TeL=0.6932, TeA=0.7417, Epoch 3: TrL=0.0224, TrA=0.9996, VL=0.4205, VA=0.8494, TeL=0.6169, TeA=0.7854, Epoch 4: TrL=0.0107, TrA=1.0000, VL=0.4251, VA=0.8463, TeL=0.6164, TeA=0.7760, Epoch 5: TrL=0.0071, TrA=1.0000, VL=0.3946, VA=0.8536, TeL=0.5990, TeA=0.7865, Epoch 6: TrL=0.0052, TrA=1.0000, VL=0.4075, VA=0.8515, TeL=0.5714, TeA=0.7906, Epoch 7: TrL=0.0040, TrA=1.0000, VL=0.3773, VA=0.8609, TeL=0.5512, TeA=0.8010, Epoch 8: TrL=0.0033, TrA=1.0000, VL=0.3643, VA=0.8661, TeL=0.5491, TeA=0.8052, Epoch 9: TrL=0.0028, TrA=1.0000, VL=0.3768, VA=0.8598, TeL=0.5377, TeA=0.8042, Epoch 10: TrL=0.0023, TrA=1.0000, VL=0.3760, VA=0.8640, TeL=0.5380, TeA=0.8031
As you can see, after 2-3 epochs, training accuracy goes to 100% and training loss goes to less than 1%. But in validation accuracy is around 90-95% and in test, accuracy is around 90%. How can I interpret these results? My models are overfitting? Or they are good? For example, model 2) in the best case has TrA 1, VA 0.9802 and TeA 0.9292. I think that in this case It is not overfitting, because results are similar.
Last question: I have understood that among the epochs, I have to choose as best model, the one in which Validation Accuracy is highest. Why this? Why I cannot take the epoch in which test accuracy is the highest?