This entry is associated with using ImageJ.  Using google I found an image of a flock of birds:

I then loaded this image into ImageJ and transformed it into a black and white 8-bit version (trimming out erroneous bits).  After which I analyzed particles which produced the following image:

The above image came along with data.  The relevant data being the count which was 15.  Counting birds within a flock can become relatively more difficult when multiple birds are grouped together.  When information is taken away from the image multiple birds would get grouped into the same pixel set.  There are likely tools available to address this sort of issue within ImageJ.

I decided that I didn’t really much care for the bird one… so following the same procedure I did this again except for something that I hate doing manually.  Counting E. coli colonies.

The first image below is the original and the second is the analyzed image 185 colonies in total: