Thank you, Stéfan and Emma!
It really helped me to extract the objects after segmentation! (skimage.measure and other subpackages) I'm trying to perform indirect georeferencing of image where the object of interest will be the markers which represent GCP (Ground Control Point). These markers will be segmented and then the centroid of the segmented markers will correspond to the position of GCP in image. Right now, I'm using SLIC algorithm (Simple Linear Iterative Clustering) (skimage.segmentation.slic). According to your opinion, which segmentation algorithm would give better result. (even though the segmentation algorithm to be used depends upon the type/quality of the image) Again, thank you very much! waiting for your response!