Add GlobalAveragePooling2D (before ResNet50) - python

I'm trying to do a model using ResNet50 for image classification into 6 classes and I want to reduce the dimension of the images before using them to train the ResNet50 model. To do this I start creating a ResNet50 model using the model in keras:
ResNet = ResNet50(
include_top= None, weights='imagenet', input_tensor=None, input_shape=([64, 109, 3]),
pooling=None, classes=6)
And then I create a sequential model that includes ResNet50 but adding some final layers for the classification and also the first layer for dimensionality reduction before using ResNet50:
(About the input shape: The images I'm using have a dimension of 128x217 and the 3 is for the channel that ResNet needs)
model = models.Sequential()
model.add(GlobalAveragePooling2D(input_shape = ([128, 217, 3])))
model.add(ResNet)
model.add(GlobalAveragePooling2D())
model.add(Dense(units=512, activation='relu'))
model.add(Dropout(0.5))
model.add(Dense(units=256, activation='relu'))
model.add(Dropout(0.5))
model.add(Dense(units=6, activation='softmax'))
But this doesn't work because the dimension after the first global average pooling doesn't fit with the input shape in the Resnet, the error I get is:
WARNING:tensorflow:Model was constructed with shape (None, 64, 109, 3) for input Tensor("input_6:0", shape=(None, 64, 109, 3), dtype=float32), but it was called on an input with incompatible shape (None, 3).
ValueError: Input 0 of layer conv1_pad is incompatible with the layer: expected ndim=4, found ndim=2. Full shape received: [None, 3]
I think I understand what is the problem but I don't know how to fix it since (None, 3) is not a valid input shape for ResNet50. How can I fix this? Thank you!:)

You should first understand what GlobalAveragePooling actually does. This layer cannot be apllied right after the input, because it will only give the maximum value of all the images for each channel (in your case 3 values, because you have 3 channels).
You have to use another method to reduce the size of the images (e.g. simple conversion to a smaller size.

Related

ValueError: Input 0 of layer "conv2d_21" is incompatible with the layer: expected min_ndim=4, found ndim=2. Full shape received: (None, 19222)

I'm developing a keras model for binary classification using cell genetic information from an h5ad file.
My training data is a 35000 x 19222 float matrix.
Labels:
labels = adata.obs.tier_0_hallmark_corrected
labels = labels.map({'Tumor': 1, 'Normal':0})
labelsSample = labels.iloc[:35000] #shape: (35000,)
The training samples:
expression = adata.to_df()#this is taken from a file that contains genetic information
expressionSample = expression.iloc[:35000] #Shape: (35000, 19222)
Keras model:
input_dim = 19222
model = Sequential()
model.add(Conv2D(64, 3, activation='selu', input_shape = (input_dim,)))
model.add(Conv2D(64, 3, activation='selu'))
model.add(Dropout(0.5))
model.add(BatchNormalization())
model.add(Conv2D(128, 3, activation='selu'))
model.add(Dropout(0.5))
model.add(BatchNormalization())
model.add(Conv2D(128, 3, activation='selu'))
model.add(Dropout(0.5))
model.add(BatchNormalization())
model.add(Dense(1, activation='sigmoid'))
model.summary()
When I execute the model I get: ValueError: Input 0 of layer "conv2d_21" is incompatible with the layer: expected min_ndim=4, found ndim=2. Full shape received: (None, 19222). I assume I have to reshape the input data into the model but I don't really know what shape should it have. I'm pretty new to DL so help is much appreciated ;)
You have a problem with the shape of the input.
You should investigate a bit the content of your train data. Conv2D expects an input_shape of 4. You are inserting a shape of 2 (1922 and the batch size that is taken automatically).
For example, if train data are images 28x28 RGB (three channels) the input_shape would be (28, 28, 3). So you would have 4 dimensions (including batch size).
You have to understand better the content of your data and possibly reshape it. Or maybe this is not the right architecture for you.
As the OP was saying in the comments the final solution was to change Conv2D to Conv1D.

Python Keras Sequential model input

I have an array for attempting some times series sliding window method for machine learning forecasting with tf.Keras:
X.shape
(8779, 6, 1)
to fit the MLP model:
# define model
model = Sequential()
model.add(Dense(100, activation='relu', input_shape=(6,)))
model.add(Dense(1))
model.compile(optimizer='adam', loss='mse')
Could anyone give me a tip on how to correct this model input?
input_shape=(6,)
I cant figure out to how get past this error:
ValueError: Input 0 of layer sequential is incompatible with the layer: expected axis -1 of input shape to have value 6 but received input with shape (None, 6, 1)
Even though it was solved by a recommendation from comments, here is the solution:
Changing:
input_shape=(6,)
Into:
input_shape=(6,1)
worked.

The input shape and fitting in Keras LSTM model

I am learning the LSTM model to fit the data set to the multi-class classification, which is eight genres of music, but unsure about the input shape in the Keras model.
I've followed the tutorials here:
How to reshape input data for LSTM model
Multi-Class Classification Tutorial with the Keras Deep Learning Library
Sequence Classification with LSTM Recurrent Neural Networks in Python with Keras
My data is like this:
vector_1,vector_2,...vector_30,genre
23.5 20.5 3 pop
.
.
.
(7678)
I transformed my data shape into (7678,1,30), which is 7678 pieces of music, 1 timestep, and 30 vectors. For the music genre, I used train_labels = pd.get_dummies(df['genre'])
Here is my model:
# build a sequential model
model = Sequential()
# keras convention to use the (1,30) from the scaled_train
model.add(LSTM(32,input_shape=(1,30),return_sequences=True))
model.add(LSTM(32,return_sequences=True))
model.add(LSTM(32))
# to avoid overfitting
model.add(Dropout(0.3))
# output layer
model.add(Dense(8,activation='softmax'))
model.compile(optimizer='adam',loss='categorical_crossentropy',metrics=['accuracy'])
Fitting the model
model.fit(scaled_train,train_labels,epochs=5,validation_data=(scaled_validation,valid_labels))
But when trying to fit the model, I got the error ValueError: Shapes (None, 8) and (None, 1, 8) are incompatible. Is there anything I did wrong in the code? Any help is highly appreciated.
The shape of my data
print(scaled_train.shape)
print(train_labels.shape)
print(scaled_validation.shape)
print(valid_labels.shape)
(7678, 1, 30)
(7678, 8)
(450, 30)
(450, 8)
EDIT
I've tried How to stack multiple lstm in keras?
But still, get the error ValueError: Input 0 of layer sequential_21 is incompatible with the layer: expected ndim=3, found ndim=2. Full shape received: [None, 30]
As the name suggests, return_sequences=True will return a sequence (with a time step), That's why your output shape is (None, 1, 8): the time step is maintained. It doesn't flatten automatically when it goes through the dense layer. Try:
model = Sequential()
model.add(LSTM(32,input_shape=(1,30),return_sequences=False))
model.add(Dense(32,activation='relu'))
model.add(Dropout(0.3))
model.add(Dense(8,activation='softmax'))
I guess this doesn't happen if you uncomment the second LSTM layer?

ValueError: Error when checking target: expected dense_13 to have shape (None, 6) but got array with shape (6, 1)

I am training a classification network with training data which has X.shape = (1119, 7) and Y.shape = (1119, 6). Below is my simple Keras network with and output dim of 6 (size of labels). The error which is returned is below the code
hidden_size = 128
model = Sequential()
model.add(Embedding(7, hidden_size))
#model.add(LSTM(128, input_shape=(1,7)))
model.add(LSTM(hidden_size, return_sequences=True))
model.add(LSTM(hidden_size, return_sequences=True))
model.add(Dense(output_dim=6, activation='softmax'))
# Compile model
model.compile(loss='categorical_crossentropy',
optimizer='adam',
metrics=["categorical_accuracy"])
ValueError: Error when checking target: expected dense_13 to have shape (None, 6) but got array with shape (6, 1)
I would perfer not to do this in tensorflow because I am just prototyping yet it is my first run at Keras and am confused about why it cannot take this data. I attempted to reshape the data in a number of ways in which nothing worked. Any advice as to why this isn't work would be greatly appreciated.
You should probably remove the parameter return_sequences=True from your last LSTM layer. When using return_sequences=True, the output of the LSTM layer has shape (seq_len, hidden_size). Passing this on to a Dense layer gives you an output shape of (seq_len, 6), which is incompatible with your labels. If you instead omit return_sequences=True, then your LSTM layer returns shape (hidden_size,) (it only returns the last element of the sequence) and subsequently your final Dense layer will have output shape (6,) like your labels.

Input of 3D array into Sequential model Keras (Python)

I have a training input in 3 dimensions (8,50,3).
I am trying to pass it as an input to the Sequential Model in Keras. Looking up the documentation I found that this should work:
model = Sequential()
model.add(Dense(100, activation='relu', input_shape=(50,3)))
model.add(Dense(100,init="uniform", activation='sigmoid'))
model.add(Dense(50,init="uniform", activation='relu'))
model.add(Dense(output_dim=1))
model.compile(optimizer='rmsprop',loss='categorical_crossentropy',metrics=['accuracy'])
When I try to train this model:
model.fit(train,labelTrain,epochs=1,batch_size=1,verbose=1)
I get the following error:
Error when checking model target: expected dense_148 to have 3 dimensions, but got array with shape (8, 1)
What can it mean?
Also, my first objective was to pass a 3D array where the middle dimension did not have a fixed size but I gave up after finding it impossible. Could it work?
Target means it's the expected result. The problem is in labelTrain, not in the input.
A Dense layer must have a number of neurons. You don't pass it an output shape, you pass the amount of neurons, and the output is automatically (None, neurons)
Your last layer should be:
model.add(Dense(1, activation='I recomend an activation here'))

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