again, a strange argument is being made here.
One thing is to let the user to adjust the images in his library (and of course for his interest and benefit) and free riding to improve your commercial product. Borderline, but acceptable.
Other thing is to ask people to edit images that are of no interest to them, only to your benefit. And dressing this up as a crowdsourcing beauty. This is hardly crowdsorcing. That seems to me downright taking advantage.
At least be straightforward: “we thank you for donating your time and effort for making our product better”