2
$\begingroup$

I am using a CNN to classify medical images. I am using a four convolutional layers with ReLU activation followed by a softmax layer. I am using rmsprop as the optimizer. The problem I am facing is the network's test accuracy increases and then goes down. This continues till the maximum number of epochs is reached. I read somewhere that this could be due to the fact that the network shifts its weights in favor of one class, and then has to do so in favor of the other class. I shuffled the test data, to see if this would help, but no such luck. Is there any remedy?

enter image description here

$\endgroup$
2
$\begingroup$

Based on the image you are sharing, the training accuracy continues to increase, the validation accuracy is changing around the 50%. I think either you do not have enough data to use neural network or the network is small to capture all the information, in both cases I feel there either under fitting or over fitting problem. Can you give us some information about the database so we can help more

$\endgroup$
  • $\begingroup$ journals.plos.org/plosone/article?id=10.1371/…. That is the network I am trying to implement. I have 100 MRI images. I have followed the same procedure as in the paper I have linked to. It is a very similar database. $\endgroup$ – Raghuram Dec 31 '16 at 15:20
  • $\begingroup$ 100 images is very few , you can not use DNN $\endgroup$ – Bashar Haddad Dec 31 '16 at 22:17
  • $\begingroup$ Try to use hog or sift with sparse coding and svm $\endgroup$ – Bashar Haddad Dec 31 '16 at 22:18
  • $\begingroup$ Sorry, I did not make myself clearer. The MRI images have a varying number of slices. I extract these slices, and augment them by rotating them. This gives me around 10k 'images' to work with. The test set is around 1k slices, but it is heavily imbalanced. $\endgroup$ – Raghuram Jan 1 '17 at 3:27
  • $\begingroup$ What is the learning rate you are using? $\endgroup$ – Himanshu Rai Jan 1 '17 at 4:39

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.