Subject: Complex object length quantification - msg#00172

Happy holiday to everyone,
I am trying to measure the number of and individual lengths of spikes
growing out of a central bead (sphere). In particular, I would like to
draw 3 progressively larger circles (100 microns, 200 microns, and 300
microns in diamenter) around the bead and have ImageJ count the number
of points crossing a particular circle. This way we could see the
number of spikes crossing the 100 or 200 or 300 micron circles to
determine how many spokes are larger than 300 microns, 200-300 microns,
and finally 100-200 microns in length. Finally, I would like the data
to be dumped into an excel spreadsheet.

Assumptions:
1) all spokes radiate from the central bead.
2) the bead can be photographed so that it is in the center of the
field.
3) one bead per image

Note: if it makes life significantly easier, I can take flouresent
images so that the contrast is significantly improved and the program
may be able to identify "spokes" more easily.
Thanks to everyone for their help

Anil