Here is one website that can assist with portraits.
It is easy to use and the portraits are cropped online (on the fly). However, it can only work with certain portrait sizes and requires a minimum of 600 x 600 pixels to work. So it won't work with small photos.
It will also not work if the height of the photo is not over the edge of the frame at the top. It will give an error message.
This online tool gives almost a square image but it is good for setting faces of the same size.
I tried working on some of the portraits.
|Re-sizing portrait to a preset fixed size or alignment grid|