Sentence:  Here we use the position of each region inside the image, its size, structure and adjacency relations to the other prominent regions or to the background. First we apply a so-called preprocessing step, in which we separate <WSD>objectable</WSD> images from non-objectable ones with the meaning of whether or not the given image contains prominent regions. 
Meaning of the word marked with <WSD> tags:  Capable of being made into or treated as an object (especially by a computer program or programming language).