Extracting Features Using TensorFlow CNN
CNN feature extraction in TensorFlow is now made easier using the tensorflow/models repository on Github. There are pre-trained VGG, ResNet, Inception and MobileNet models available here.

I have used the following wrapper for convenient feature extraction in TensorFlow. You can just provide the tool with a list of images. It will pre-process the images and extract the features by feed-forwarding through the network. You can specify the layer names that you want to extract and save them to HDF5 or pickle afterwards. 

https://github.com/tomrunia/TF_FeatureExtraction