Imagine a hypothetical scenario where the image of interest contains a person and sky in the background. Furthermore, for this scenario, let's assume that there is little change in pixel intensity of the background (sky) and that there is a considerable change in pixel intensity of the foreground (the person).
Just from the preceding description itself, we can conclude that there are two primary regions here – one is of the person and the other is of the sky. Furthermore, within the region of the image of a person, the pixels corresponding to hair will have a different intensity to the pixels corresponding to the face, establishing that there can be multiple sub-regions within a region.
Region proposal is a technique that helps in identifying islands of regions where the pixels are similar to one another.
Generating a region proposal comes in handy for object detection where we have to identify the locations of objects present in the image....