"Select Wizard"

[cailadd]

Hi,
   I'm doing a science project on saltmarshes. I want to see how they change over time. To help me do this, I was hoping to use ImageJ.

What I'll do is open a photo on ImageJ, then contrast the image so the 'green' plants stand out from the 'white' sand as strongly as possible. I then want to select all the 'green' pixels, and create a polygon (and eventually shapefile for ArcGIS).

Any ideas on how to select all the 'green' pixels like this? I know something similar can be done on Photoshop, and I think the tool is called 'select wizard'.

Thanks,
   Cai