imaging - Automatic cropping of collimated digital X-ray images

Do you have any suggestions for a library which offers an algorithm to crop digital X-ray images automatically?

We receive full-size images (43x43cm) from a detector, independent of the collimator settings. If the collimator has been closed to 10x15cm, we need to crop this area. This should be done automatically, so that the user does not even see the full-size image because it contains a lot of information which is not needed.

Now we are looking for a good library which offers such an algorithm. This sounds like a simple task, but depending on the dose and the collimation, it can be pretty hard to detect the collimated area of the image. Therefore, we are looking for a professional solution rather than implementing it ourselves.

Any suggestions?