Converting To Tflite model - tensorflow

While converting model to tflite getting this error
"""
Some of the operators in the model are not supported by the standard TensorFlow Lite runtime and are not recognized by TensorFlow. If you have a custom implementation for them you can disable this error with --allow_custom_ops, or by setting allow_custom_ops=True when calling tf.lite.TFLiteConverter(). Here is a list of builtin operators you are using: ABS, ADD, CONV_2D, MAX_POOL_2D, MUL, RELU, SOFTMAX, SQUEEZE, SUB. Here is a list of operators for which you will need custom implementations: AdjustContrastv2, AdjustHue, AdjustSaturation, RandomUniform.
"""
How to resolve this?
tensorflow version: 1.13.1

You can use TF ops directly by selecting TF ops.
I've confirmed that AdjustContrastv2, AdjustHue, AdjustSaturation are available via FlexDelegate.
https://github.com/tensorflow/tensorflow/blob/master/tensorflow/lite/delegates/flex/allowlisted_flex_ops.cc#L35
To use this feature, you need to use TF 2.4 or higher. Since TF 2.4 is not available yet, you need to use tf-nightly release.
FYI, regarding migration TF1 to TF2, please check https://www.tensorflow.org/guide/migrate

You may try adding following lines to specify your model can use ops in both TF Lite built in and in TF.
converter.experimental_new_converter=True
converter.target_spec.supported_ops = [tf.lite.OpsSet.TFLITE_BUILTINS,
tf.lite.OpsSet.SELECT_TF_OPS]
Or better you should rewrite ops not supported in TF Lite built in by ops available in TF built in

Related

How to calculate the matrix's inverse using tflite

as far as i known, the matrix's inverse is a common operator.
while tf.raw_ops.MatrixInverse is not supported in tflite and BatchMatrixInverse is not available in GraphDef version 1205.
How can i calculate the inverse of the matrix in tflite?
Best wishes
Before you convert your model to tflite model you have to enable TF ops to work in tflite by using the below code
converter.target_spec.supported_ops = [
tf.lite.OpsSet.TFLITE_BUILTINS, # enable TensorFlow Lite ops.
tf.lite.OpsSet.SELECT_TF_OPS # enable TensorFlow ops.
]
For more details please refer to this document. Thank You.

keras multi_gpu_model saved_model failed to load model in TF2 code

I have trained a multi_gpu_model using tensorflow 1.13/1.14 and saved them with keras.model.save('<.hdf5>').
Now, after migrating to tensorflow 2.4.1, in which Keras is integrated as tensorflow.keras, I cannot tensorflow.keras.models.load_model as I did before, due to the following error:
AttributeError: module 'tensorflow.python.keras.backend' has no attribute 'slice'
After trying to import keras.models.load_model, and trying different versions of keras (2.2.4 -> 2.4.1) and tensorflow (2.2 -> 2.4.1), I cannot load_model from my .hdf5 file using my TF 2.2+ code.
I do know that in TF 2.X + we can train using distributed machines by implementing the "strategy" scope, and it does work, but I have a lot of "old" models that I need to work on the same code base which is now being migrated to TF 2.4.1
Apparently the problem was not the TF versions, but the way I was saving my models on my TF 1.X code versions.
I used the keras.multi_gpu_model class for both training and saving, while this practice is wrong, as clearly stated on Keras documentation:
"To save the multi-gpu model, use .save(fname) or .save_weights(fname)
with the template model (the argument you passed to multi_gpu_model),
rather than the model returned by multi_gpu_model."
So, after figuring this out a method for model conversion, using TF 1.X code, was adopted:
build you model from scratch, namely new_model
load your pre-trained weights from the multi_gpu_model, namely 'old_model'
copy your old_model's weights, which is old_model.layers[3] (due to the wrong usage of multi_gpu_model) to your new_model
save new_model as .hdf5 file
use new_model.hdf5 everywhere - TF 1.X and TF 2.X

Missing some boosted trees operations in Tensorflow Lite

I have a Tensorflow model based on BoostedTreesClassifier and I want to deploy it on a mobile with the help of Tensorflow Lite.
However, when I try to convert my model to the Tensorflow Lite model I get an error saying that there are unsupported operations (as of Tensorflow v2.3.1):
tf.BoostedTreesBucketize
tf.BoostedTreesEnsembleResourceHandleOp
tf.BoostedTreesPredict
tf.BoostedTreesQuantileStreamResourceGetBucketBoundaries
tf.BoostedTreesQuantileStreamResourceHandleOp
Adding tf.lite.OpsSet.SELECT_TF_OPS option helps a bit, but still some operations need a custom implementation:
tf.BoostedTreesEnsembleResourceHandleOp
tf.BoostedTreesPredict
tf.BoostedTreesQuantileStreamResourceGetBucketBoundaries
tf.BoostedTreesQuantileStreamResourceHandleOp
I've also tried Tensorflow v2.4.0-rc3, which reduces the set to the following one:
tf.BoostedTreesEnsembleResourceHandleOp
tf.BoostedTreesPredict
Conversion code is like the following:
converter = tf.lite.TFLiteConverter.from_saved_model(model_path, signature_keys=['serving_default'])
converter.target_spec.supported_ops = [
tf.lite.OpsSet.TFLITE_BUILTINS,
tf.lite.OpsSet.SELECT_TF_OPS
]
tflite_model = converter.convert()
signature_keys is specified explicitly, because the model exported with BoostedTreesClassifier#export_saved_model has multiple signatures.
Is there a way to deploy this model on mobile other than writing custom implementation for non-supported ops?

TF-Lite Non-Max-Suppression

I am attempting to convert a graph with tf.image.non_max_suppression or tf.image.combined_non_max_suppression but both API calls yield an error like "tf.CombinedNonMaxSuppression op is neither a custom op nor a flex op." My setup is TF2.3.1, python 3.7, Windows 10.
I understand that some tf functions are not supported for conversion to TF-Lite but the link below shows tfl function for non-max-suppression.
https://tensorflow.google.cn/mlir/tfl_ops#tflnon_max_suppression_v4_tflnonmaxsuppressionv4op
What do I need to do to be able to run the converter on my function in order to use the tfl.non_max_suppression_vx function?
Non-max-suppression operation is not supported in TF Lite. If you want to use them you have to use via TF lib, when converting, adding these lines
converter.experimental_new_converter=True
converter.target_spec.supported_ops = [tf.lite.OpsSet.TFLITE_BUILTINS,
tf.lite.OpsSet.SELECT_TF_OPS]
There is an other way that you should rewrite NMS op by ops supported in TF Lite or sort of so. If you rewrite successfully, please tell me. Thanks.

"Unkown (custom) loss function" when using tflite_convert on a {TF 2.0.0-beta1 ; Keras} model

Summary
My question is composed by:
A context in which I present my project, my working environment and my workflow
The detailed problem
The concerned parts of my code
The solutions I tried to solve my problem
The question reminder
Context
I've written a Python Keras implementation of a downgraded version of the original Super-Resolution GAN. Now I want to test it using Google Firebase Machine Learning Kit, by hosting it in the Google servers. That's why I have to convert my Keras program to a TensorFlow Lite one.
Environment and workflow (with the problem)
I'm training my program on Google Colab working environment: there, I've installed TF 2.0.0-beta1 (this choice is motivated by this uncorrect answer: https://datascience.stackexchange.com/a/57408/78409).
Workflow (and problem):
I write locally my Python Keras program, keeping in mind that it will run on TF 2. So I use TF 2 imports, for example: from tensorflow.keras.optimizers import Adam and also from tensorflow.keras.layers import Conv2D, BatchNormalization
I send my code to my Drive
I run without any problem my Google Colab Notebook: TF 2 is used.
I get the output model in my Drive, and I download it.
I try to convert this model to the TFLite format by executing the following CLI: tflite_convert --output_file=srgan.tflite --keras_model_file=srgan.h5: here the problem appears.
The problem
Instead of outputing the TF Lite converted model from the TF (Keras) model, the previous CLI outputs this error:
ValueError: Unknown loss function:build_vgg19_loss_network
The function build_vgg19_loss_network is a custom loss function that I've implemented and that must be used by the GAN.
Parts of code that rise this problem
Presenting the custom loss function
The custom loss function is implemented like that:
def build_vgg19_loss_network(ground_truth_image, predicted_image):
loss_model = Vgg19Loss.define_loss_model(high_resolution_shape)
return mean(square(loss_model(ground_truth_image) - loss_model(predicted_image)))
Compiling the generator network with my custom loss function
generator_model.compile(optimizer=the_optimizer, loss=build_vgg19_loss_network)
What I've tried to do in order to solve the problem
As I read it on StackOverflow (link at the beginning of this question), TF 2 was thought to be sufficient to output a Keras model which would be correctly processed by my tflite_convert CLI. But it's not, obviously.
As I read it on GitHub, I tried to manually set my custom loss function among Keras' loss functions, by adding these lines: import tensorflow.keras.losses
tensorflow.keras.losses.build_vgg19_loss_network = build_vgg19_loss_network. It didn't work.
I read on GitHub I could use custom objects with load_model Keras function: but I only want to use compile Keras function. Not load_model.
My final question
I want to do only minor changes to my code, since it works fine. So I don't want, for example, to replace compile with load_model. With this constraint, could you help me, please, to make my CLI tflite_convert works with my custom loss function?
Since you are claiming that TFLite conversion is failing due to a custom loss function, you can save the model file without keep the optimizer details. To do that, set include_optimizer parameter to False as shown below:
model.save('model.h5', include_optimizer=False)
Now, if all the layers inside your model are convertible, they should get converted into TFLite file.
Edit:
You can then convert the h5 file like this:
import tensorflow as tf
model = tf.keras.models.load_model('model.h5') # srgan.h5 for you
converter = tf.lite.TFLiteConverter.from_keras_model(model)
tflite_model = converter.convert()
open("converted_model.tflite", "wb").write(tflite_model)
Usual practice to overcome the unsupported operators in TFLite conversion is documented here.
I had the same error. I recommend changing the loss to "mse" since you already have a well-trained model and you don't need to train with the .tflite file.