my company has recently started to get problems with the image handling for our websites.
We have several websites (adult entertainment) that display images like dvd cov
In the time that this question has been asked, a few companies have sprung up to deal with this exact issue. It is not an issue that's isolated to you or your company. Many companies reach the point where they need to look for a more permanent solution for their image processing needs.
Services like imgix serve as a proxy and CDN for image operations like resizing and applying overlays. By manipulating the URL, you can apply different transformations to each image. imgix serves billions of requests per day.
You can also stand up services on your own and put them behind a CDN. Open source projects like imageproxy are good for this. This puts the burden of maintenance on your operations team.
(Disclaimer: I work for imgix.)
This exact same problem is now being solved by image resize services dedicated to this task. They provide following features:
One such service is Gumlet. You can also try some open source alternative like nginx plugin which can also resize image on the fly.
(I work for Gumlet.)