I am writing something in C#/.NET in Visual Studio to find blobs (small white circles on a dark background. I need to translate these center points of the blob to real world coordinates. I would need a calibration capability and a blob detection capability.
I would like to start with a free library to prove the concept and move on to a paid version (if needed) if the proof of concept is successful. Currently speed is not the most important. Ease of use and good documentation would be nice.
Edit
Here is an image that is somewhat similar to the kind of images I am looking to find blobs in: