I'm trying to analyse two contours and give a percent corresponding to their similarity. Assuming I have all the point's coordinates describing these contours (just like an SVG path), based on which factor should I tell they're almost identical ?

After some Google searches, I found something related to Fourier descriptors, are they relevant for my case ?

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Edit
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What I want to do is to compare several fonts to another one. Just like would do [What the font](http://www.myfonts.com/WhatTheFont/), but not with an image. Thanks to the produced algorithm, it would be possible to find a font equivalent according to the similarity percentage.

Some scripts just compare the bounding box for each letters, but it's not enough. I need a way to tell that Arial is closest to Verdana than to Webdings. So assuming I can extract the contour from the fonts, I need a way to compare two contours.

For example (with "logical" percent values):

![Font comparison, the bold G is the closest](https://i.stack.imgur.com/Lre3O.png)