Using Matching Filters to Detect Coins in an Image

If I have the following image of coins eroded after dilation:

and I want to classify them as dimes, nickels, and quarters through three matching filters dimefilter, nickelfilter, and quarterfilter. By knowing the centroids of those circles obtained by using "regionprops" function, how can I for each ith coin centroid compute the jth (If j=1,2, and 3 for dimes, nickels, and quarters filters resp.) matching filter result by computing the correlation between the matching filter and the local region of image pixels that fall within half the matching filter width rows and columns to the centroid.

Thanks in Advance.