I used Paint.net to edit my picture. Crop your picture to be square (150x150) and then when Save As, it asks for the resolution (with a slider) at which to save and it also gives you a preview of the size of the image.
Let me know if that works
Making Backyard Rinks from 1999-2015
Twitter: @kevmac_5 or @macisaac_odr
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