update with tensorflow checkpoints and more code changes

notebooks/visualize_filters_keras.ipynb

ptx_tensorflow/best_classifier.pt/keras_metadata.pb

ptx_tensorflow/best_classifier.pt/saved_model.pb

...est_classifier.pt/variables/variables.data-00000-of-00001

ptx_tensorflow/best_classifier.pt/variables/variables.index

ptx_tensorflow/sparse.pt/keras_metadata.pb

ptx_tensorflow/sparse.pt/saved_model.pb

...sorflow/sparse.pt/variables/variables.data-00000-of-00001

ptx_tensorflow/sparse.pt/variables/variables.index

run_ptx.py

run_tflite_pnb.py

run_tflite_ptx.py

sparse_coding_torch/convert_pytorch_to_keras.py

sparse_coding_torch/keras_model.py

sparse_coding_torch/load_data.py

sparse_coding_torch/train_classifier.py

sparse_coding_torch/video_loader.py