If the input data is in numpy array format, then we can declare a placeholder in the graph and feed the placeholder with the numpy array data. However, if the input data is already in Tensor format (this is the case when we load jpg files using tf.image.decode_jpeg), then we can't feed a Tensor to a placeholder. In this case, should we use non trainable TF Variables as placeholders, and feed the Tensor to these Variables by tf.assign?
Figured it out. You can simply feed batches of Tensors to the model. The model probably has a line that looks similar to op = optimizer.minimize(loss). Then, each time sess.run(op) is called, the model will be trained on the batch provided to it. Also, each time sess.run(op) is called, we should have a different batch if we use tf.train.batch to provide the batch.
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I have a class 'tensorflow.python.framework.ops.Tensor as output and need to convert this to a numpy array.
.numpy() doesn't work because it isn't a eagerTensor.
.eval doesn't work as well, because i'm using tensorflow >2.0
Is there any other way to fix this?
img_height=330
img_width=600
img_depth=23
save_model="saved_Models/wheatModel"
prediction_data_path=["data/stacked/MOD13Q1.A2017.2738.tif","data/stacked/MOD13Q1.A2017.889.tif","data/stacked/MOD13Q1.A2017.923.tif"]
prediction_data=dataConv.preparePredictionData(prediction_data_path)
prediction_reshaped=dataConv.reshapeFiles(prediction_data,img_width,img_height,img_depth)
x_ds =tf.stack(prediction_reshaped)
model = tf.keras.models.load_model(save_model)
model.predict(x_ds)
image=model.get_layer(name='prediction_image').output
n,output_width,output_height,output_depth,output_channels=image.shape
print(type(image))
image=tf.reshape(image,(output_width,output_height,output_depth))
print(type(image))
image.numpy()
So in the code above.
I load my trained model
predict the given images
get the output from the next to last layer
reshape this data
Now i want to convert this tensor to an numpyarray
I am trying to predict() the output for a single data point d, using my trained Keras model loaded from a file. But I get a ValueError If predicting from data tensors, you should specify the 'step' argument. What does that mean?
I tried setting step=1, but then I get a different error ValueError: Cannot feed value of shape () for Tensor u'input_1:0', which has shape '(?, 600)'.
Here is my code:
d = np.concatenate((hidden[p[i]], hidden[x[i]])).resize((1,600))
hidden[p[i]] = autoencoder.predict(d,steps=)
The model is expecting (?,600) as input. I have concatenated two numpy arrays of shape (300,) each to get (600,), which is resized to (1,600). This (1,600) is my input to predict().
In my case, the input to predict was None (because I had a bug in another part of the code).
In official doc, steps refer to the total number of steps before stopping. So steps=1 means make predictions on one batch instead of making prediction on one record (single data point).
https://keras.io/models/sequential/
-> Define value of steps argument,
d = np.concatenate((hidden[p[i]],
hidden[x[i]])).resize((1,600))
hidden[p[i]] = autoencoder.predict(d,steps=1)
If you are using a test data generator, it is good practice to define the steps, as mentioned in the documentation.
If you are predicting a single instance, no need to define the steps. Just make sure the argument (i.e. instance 'd') is not None, otherwise that error will show up. Some reshaping may also be necessary.
in my case i got the same error, i just reshaped the data to predict with numpy function reshape() to the shape of the data originally used to train the model.
I have a model much like the tensorflow speech command demo except it takes a variable sized 1D array as input. Now I find it difficult to convert this model to TF lite using tflite_convert which requires input_shape for input.
It's said that tf lite requires fixed size input for efficiency and you can resize input during inference as part of your model. However, I think it would involve truncating the input which I don't want. Is there any way to make this work with TF lite?
You can convert your model using a fixed shape as in --input_shape=64, then at inference-time you would do:
interpreter->ResizeInputTensor(interpreter->inputs()[0], {128});
interpreter->AllocateTensors();
// ... populate your input tensors with 128 entries ...
interpreter->Invoke();
// ... read your output tensor ...
In Keras, we don't specify what the input is, we rather specify its shape. How does Keras choose what array to use as an input?
For example, I have two models that have different input, but the two inputs have the same shape. How can I specify which input goes to which model?
Models in Keras/Tensorflow are first "designed", only when they are ready you feed them with data.
The model receives the data when you call any of these:
model.fit()
model.fit_generator()
model.train_on_batch()
model.predict()
model.predict_generator()
I want to use transfer learning with Google's Inception network for an image recognition problem. I am using retrain.py from the TensorFlow example source for inspiration.
In retrain.py, the Inception graph is loaded and a feed dict is used to feed the new images into the model's input layer. However, I have my data serialized in TFRecord files and have been using an input pipeline to feed in my inputs, as demonstrated here.
So I have a tensor images which returns my input data in batches when run. But how can I feed these images into Inception? I can't use a feed dict since my inputs are tensors, not NumPy arrays. My two ideas are
1) simply call sess.run() on each batch to convert it to a NumPy array, and then use a feed dict to pass it to Inception.
2) replace the input node in the Inception graph with my own batch input tensor
I think (1) would work, but it seems a little inelegant. (2) seems more natural to me, but I can't do exactly that because TensorFlow graphs can only be appended to and not otherwise modified.
Is there a better approach?
You can implement option (2), replacing the input node, but you will need to modify retrain.py to do so. The tf.import_graph_def() function supports a limited form of modification to the imported graph, by remapping tensors in the imported graph to existing tensors in the target graph.
This line in retrain.py calls tf.import_graph_def() to import the Inception model, where jpeg_data_tensor becomes the tensor that you feed with input data:
bottleneck_tensor, jpeg_data_tensor, resized_input_tensor = (
tf.import_graph_def(graph_def, name='', return_elements=[
BOTTLENECK_TENSOR_NAME, JPEG_DATA_TENSOR_NAME,
RESIZED_INPUT_TENSOR_NAME]))
Instead of retrieving jpeg_data_tensor from the imported graph, you can remap it to an input pipeline that you construct yourself:
# Output of a training pipeline, returning a `tf.string` tensor containing
# a JPEG-encoded image.
jpeg_data_tensor = ...
bottleneck_tensor, resized_input_tensor = (
tf.import_graph_def(
graph_def,
input_map={JPEG_DATA_TENSOR_NAME: jpeg_data_tensor},
return_elements=[BOTTLENECK_TENSOR_NAME, RESIZED_INPUT_TENSOR_NAME]))
Wherever you previously fed jpeg_data_tensor, you no longer need to need it, because the inputs will be read from the input pipeline you constructed. (Note that you might need to handle resized_input_tensor as well... I'm not intimately familiar with retrain.py, so some restructuring might be necessary.)