OpenCV 4 with Python Blueprints - Second Edition

Detecting proto-objects in a scene

In a sense, the saliency map is already an explicit representation of proto-objects, as it contains only the interesting parts of an image. So now that we have done all the hard work, all that is left to do in order to obtain a proto-object map is to threshold the saliency map.

The only open parameter to consider here is the threshold. Setting the threshold too low will result in labeling a lot of regions as proto-objects, including some that might not contain anything of interest (false alarm). On the other hand, setting the threshold too high will ignore most of the salient regions in the image and might leave us with no proto-objects at all.

The authors of the original spectral residual paper chose to ...