Normally, you can use a tool called strip_unused.py, located at the same location as freeze_graph.py at tensorflow/python/tools, to remove the DecodeJpeg operation that is not included in the TensorFlow core library (see https://www.tensorflow.org/mobile/prepare_models#removing_training-only_nodes for more details), but since the input node image_feed requires the decode operation (Figure 6.2), a tool such as strip_unused won't treat the DecodeJpeg as unused so it won't be stripped. You can verify this by first running the strip_unused command as follows:
bazel-bin/tensorflow/python/tools/strip_unused --input_graph=/tmp/image2text_frozen.pb --output_graph=/tmp/image2text_frozen_stripped.pb --input_node_names="image_feed,input_feed,lstm/state_feed" ...
