As long as they are all in a single field of view and well separated, it shouldn't be too difficult.
I would first create a binary image by thresholding the original image at an appropriate level to separate the particles from the background. You can use IMAQ BasicParticle to count the particles and get their locations. Then you will have to go back to the original image to figure out what the intensity of each particle is. The method for measuring the intensity will depend on what you need it for. You can take the brightest, or average, or center, etc. It might be useful to use the binary image as a mask when measuring intensity.
Bruce
Bruce Ammons
Ammons Engineering