I have an app that needs to generate hundreds and eventually thousands of images. What tools can I use to generate these images at scale. After I figure that out, then I will be looking at Rubbrband for quality control.

If you've got an nvidia graphics card with 8GB of vram made in the last decade, AUTOMATIC1111's stable diffusion web ui [1] will crank out a few thousand images every 24 hours. Depending on settings and how fast your card is, naturally.

And there's a large ecosystem of downloadable models available online for specific looks and concepts, like models trained for photorealism.

[1] https://github.com/AUTOMATIC1111/stable-diffusion-webui