Tensorflow Retrain the retrained model - tensorflow

I am very new to Neural network and tensorflow, just starting on the retrain image tutorial. I have successfully completed the flower_photos training and i have 2 questions.
1.) Is it a good/bad idea to keep building upon a retrained model many times over and over? Or would it be a lot better to train a model fresh everytime? That leads to my second question
2.) If it is ok to retrain a model over and over, for the retrain model tutorial in Tensorflow (Image_retraining), in the retrain.py would i simply replace the classify_image_graph_def.pb and imagenet_synset_to_human_label_map.txt with the one outputted from my retraining? But i see that there is also a imagenet_2012_challenge_label_map_proto.pbtxt, would i have to replace that one with something else?
Thanks for your time

Related

Is that a good idea to use transfer learning in real world projects?

SCENARIO
What if my intention is to train for a dataset of medical images and I have chosen a coco pre-trained model.
My Doubts
1 Since I have chosen medical images there is no point of train it on COCO dataset, right? if so what is a possible solution to do the same?
2 Adding more layers to a pre-trained model will screw the entire model? with classes of around 10 plus and 10000's of training datasets?
3 Without train from scratch what are the possible solutions , like fine-tuning the model?
PS - let's assume this scenario is based on deploying the model for business purposes.
Thanks-
Yes, it is a good idea to reuse the Pre-Trained Models or Transfer Learning in Real World Projects, as it saves Computation Time and as the Architectures are proven.
If your use case is to classify the Medical Images, that is, Image Classification, then
Since I have chosen medical images there is no point of train it on
COCO dataset, right? if so what is a possible solution to do the same?
Yes, COCO Dataset is not a good idea for Image Classification as it is efficient for Object Detection. You can reuse VGGNet or ResNet or Inception Net or EfficientNet. For more information, refer TF HUB Modules.
Adding more layers to a pre-trained model will screw the entire model?
with classes of around 10 plus and 10000's of training datasets?
No. We can remove the Top Layer of the Pre-Trained Model and can add our Custom Layers, without affecting the performance of the Pre-Trained Model.
Without train from scratch what are the possible solutions , like
fine-tuning the model?
In addition to using the Pre-Trained Models, you can Tune the Hyper-Parameters of the Model (Custom Layers added by you) using HParams of Tensorboard.

Quantization aware training examples?

I want to do quantization-aware training with a basic convolutional neural network that I define directly in tensorflow (I don't want to use other API's such as Keras). The only ressource that I am aware of is the readme here:
https://github.com/tensorflow/tensorflow/tree/master/tensorflow/contrib/quantize
However its not clear exactly where the different quantization commands should go in the overall process of training and then freezing the graph for actual inference.
Therefore I am wondering if there is any code example out there that shows how to define, train, and freeze a simple convolutional neural network with quantization aware training in tensorflow?
It seems that others have had the same question as well, see for instance here.
Thanks!

finetuning tensorflow seq2seq model

I've trained a seq2seq model for machine translation (DE-EN). And I have saved the trained model checkpoint. Now, I'd like to fine-tune this model checkpoint to some specific domain data samples which have not been seen in previous training phase. Is there a way to achieve this in tensorflow? Like modifying the embedding matrix somehow.
I couldn't find any relevant papers or works addressing this issue.
Also, I'm aware of the fact that the vocabulary files needs to be updated according to new sentence pairs. But, then do we have to again start training from scratch? Isn't there an easy way to dynamically update the vocabulary files and embedding matrix according to the new samples and continue training from the latest checkpoint?

Fine tune other layer beside last one for the inception v3 pretrained model using tensorflow

In my classification task, I have to fine tune the inception V3 pretrained model. However, when I search over internet, it seems like I can only fine tune the last layer of this model. I want to fine tune all layers or at least the fully connected layer not only the top one. Is there anybody has the solution for that?
Thanks
Using any existing inception training code, telling it to load from a checkpoint containing the initial value you want to use, and running the normal training procedure will let you fine tune all layers.

Would adding dropout help reduce overfitting when following tensorflow's transfer learning example?

I'm using the pretrained tensorflow inception v3 model and transfer learning to do some image classification on a new image training set I have. I'm following the instructions laid out here:
https://www.tensorflow.org/versions/r0.8/how_tos/image_retraining/index.html
However, I'm getting some severe overfitting (training accuracy is in the high 90s but CV/test accuracy is in the 50s).
Besides doing some image augmentation to try to increase my training sample size, I was wondering if doing some dropout in the retrain phase might help.
I am using this file (that came with tensorflow) as the base/template for my retraining/transfer learning:
https://github.com/tensorflow/tensorflow/blob/master/tensorflow/examples/image_retraining/retrain.py
Looking at the inception v3 model, dropout is in there. However, I don't see any dropout added in the retrain.py file.
Does it make sense that I could try to add dropout to the retraining to solve my overfitting? If so, where would I add that? If not, why?
Thanks
From Max's comment above, which was a good answer:
Max got some good improvement adding dropout to the retrain.py source. If you want to try it, you can reference his forked script. It has some additional updates, but the main part you should look at starts on line 784