A Blob is a group of connected pixels in an image that share some common property - Finding the Connection!

• Blob Detection Using OpenCV ( Python, C++ )
• The Hessian Blob Algorithm: Precise Particle Detection in Atomic Force Microscopy Imagery

see also:

• Detect and Measure Circular Objects in an Image
• Detecting Circular Objects in Images
• Fit ellipse with most points on contour (instead of least squares)
• Ellipses detecting at the image