Potentially yes. A painting made directly from a recognizable photograph can be considered a derivative work, and copyright law may restrict making or publishing derivative works without the copyright owner’s permission. Based on the answers, if the painting clearly reproduces important elements of your photo, that strengthens your position.

Because copyright rules vary by country, the exact outcome depends on Canadian law. A practical first step is to review Canadian guidance on derivative works and then contact the instructor. You could ask them to stop using the photo, remove posted images based on it, or discuss licensing/fees. If needed, you could pursue legal action, but that usually means researching local law carefully and possibly speaking with a lawyer.

In short: if the paintings are clearly recognizable as being based on your photograph and no permission was given, there may be infringement, but Canadian-specific legal advice is the safest next step.