I am using Caffe and also NVIDIA DIGITS. I want to use AlexNet pretrained on ImageNet and wanna fine tune it on my medical data. I have nearly 1000 images and using 80% for training, I generated 40,000 images by data augmentation (using cropping and rotation). However I face a severe overfitting. I tried to overcome this by adding multiple dropout layers. and the result change from :
to:
but my accuracy does not improve.
my network specifications:
AlexNet pre-trained on ImageNet
base learning rate: 0.001
learning rate multiplier: 0.1 for convolution layers and 1 for fully connected layers and xavier weight initialisation.
dropout: 0.5
Now I want to add L2 regularization. I did not find such layer in Caffe and I should maybe make it myself.
first question:
Do you have any solution for my problem? ( I have tried other ways like changing stepsize, changing learning rate from 1
to 10^(-5)
and I found 0.001
is better, weigh decay changes, adding various dropout layer (which helped as you see))
second question:
can you please help me how I can implement L2 regularization??