For ITA, just scan a existing passport size photo and use this site for bringing to specs. Use Canadian permanent resident settings.
https://www.idphoto4you.com
Make sure they are above 60kb. Don't worry about any other settings. ITA photos are like a formality and not meant for any printing purposes. Think of it like a photo stuck on an application.
The photo you need to worry about is the one that you send along with your passport after getting ppr. That should be of right specs and you can get them clicked in Walgreen.