I have 75 images of handwritten signs from which I extracted 7 Hu moments and solidity features. How can I find similarities among them to train a classifier and predict the value? I thought SVM was a good choice, but I don't have a target vector (what do I put? I do not know differences in signs that I can say there are, say, three labels, such as "circle", "triangle" or "square").
Is cluster analysis more appropriate? If yes, What is best method?
I am using the scikit-learn module in python.