A Region of Interest (ROI) is a selected portion of an image that you want to focus on for a particular task or analysis. It’s essentially a way to tell a computer, “Hey, pay special attention to this part!”
For instance, if you’re analyzing an image of cats, your ROIs are the bounding red boxes, as shown in the example image. if your goal changes to studying the grass in the same image, then the ROIs would shift to encompass the grassy areas.
So, even if the base image remains the same, the ROIs will vary depending on what you’re trying to achieve with your experiment or analysis.
Bibliography
https://en.wikipedia.org/wiki/Region_of_interest
https://erdem.pl/2020/02/understanding-region-of-interest-ro-i-pooling