Does the MATLAB has a convolutional LSTM layer

I am trying to implement a convolutional LSTM network for image classification. As the existing LSTM/Bi-LSTM layers are for 1D vector/series, I am unable to have an LSTM layer right after a convolutional layer. Is there any way to implement a convolutional LSTM in Matlab?

[Walter Roberson]

The example at https://www.mathworks.com/help/deeplearning/ug/classify-videos-using-deep-learning.html shows LSTM for video images.

[Araa]

@Walter Roberson, Thanks for the response. This example is for an LSTM layer at the end of the convolutional operations, but I am looking to have LSTM layers in between convolutional layers. Is there any existing convolutional lstm layer to perform such a task?

[Mohammad Sami]

While the following matlab example is not a direct answer to your question, it maybe possible for you to adapt it to your needs.

https://www.mathworks.com/help/deeplearning/ug/sequence-classification-using-cnn-lstm-network.html

Answer 1

[Garmit Pant]

Hello Araa

A convLSTM layer is a recurrent layer that uses convolution operations internally instead of matrix multiplications. MATLAB currently does not support the convLSTM layer.

Kindly refer to the following workaround to use LSTM networks for image classification:

• Use CNN Layers to extract features from image. The final result of Convolution must be a 1-D Vector.
• Use this 1-D vector to feed it to LSTM which will again output a new 1-D Vector.
• Output of LSTM can be used to classify the image by feeding it to a ‘classificationLayer’.

MATLAB also offers the functionality to define custom layers. You can refer to the following MathWorks documentation to understand the process of defining custom layers

https://www.mathworks.com/help/deeplearning/ug/define-custom-deep-learning-layers.html

Additionally, you can also check the following MathWorks documentation link to know the list of supported deep learning layers in MATLAB using the :

https://www.mathworks.com/help/deeplearning/ug/list-of-deep-learning-layers.html

I hope you find the above explanation and suggestions useful!

[Araa]

Garmit Pant and Mohammad Sami, thanks for the clarification.