How to run a Keras model on Android
This code is a simple example to understand how to run a Keras model on Android using Tensorflow API.
Train the model on a computer
This is a super simple model that uses Keras to learn XOR operation :
X = np.array([[0,0],[0,1],[1,0],[1,1]])
Y = np.array([[0],[1],[1],[0]])
model = Sequential()
model.add(Dense(8, input_dim=2, activation='tanh'))
model.add(Dense(1, activation='sigmoid'))
model.compile(loss='binary_crossentropy', optimizer=SGD(lr=0.1))
model.fit(X, Y, batch_size=1, nb_epoch=1000)run the python script :
python index.py
When done, the script should have created an out folder which contains several files. Among them, tensorflow_lite_xor_nn.pb, which is the model to export in Android assets folder.
Run the model on Android
public class MainActivity extends AppCompatActivity {
private TensorFlowInferenceInterface inferenceInterface;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Load model from assets
inferenceInterface = new TensorFlowInferenceInterface(getAssets(), "tensorflow_lite_xor_nn.pb");
// run the model for all possible inputs i.e. [0,0], [0,1], [1,0], [1,1]
for(int i=0 ; i<2 ; i++){
for(int j=0 ; j<2 ; j++){
float[] input = {i,j};
float[] output = predict(input);
Log.d(getClass().getSimpleName(), Arrays.toString(input)+" -> "+Arrays.toString(output));
}
}
}
private float[] predict(float[] input){
// model has only 1 output neuron
float output[] = new float[1];
// feed network with input of shape (1,input.length) = (1,2)
inferenceInterface.feed("dense_1_input", input, 1, input.length);
inferenceInterface.run(new String[]{"dense_2/Sigmoid"});
inferenceInterface.fetch("dense_2/Sigmoid", output);
// return prediction
return output;
}
}