Hello everyone. I am working on "Grading of diabetic Retinopathy into particular type". Below is the brief description about topic.

1. Classification of normal and diabetic retinal images.

2. In case of diabetic images, do identification of particular diabetic stage (mild NPDR, Moderate NPDR,Severe NPDR or PDR.

3. Classify the image according to identified stage.

I want to do feature extraction from the pre.processed using CNN. I am new to machine learning and have theoratical intution of CNN. Can someone help me with the matlab implmentation of CNN for using it as a feature extractor. Or share some useful linki in this context. I have searched alot, but cannot find any useful link.

Thankyou.