I concur that Image J or the old Image-tool from NIH will do this very well.
Most histology folks have used this, it was popular among some of us who did fluorence. Also, you can use basically any histo program at your university. :) You can also do it the old fashioned way. Print out the pictures and use calipers, rulers, or other drafting equipment to make the same comparisons. HARDLY ANYONE DOES THIS ANYMORE, but it works very well if you print the stuff out large enough! Malcolm McCallum On Tue, Jun 22, 2010 at 7:26 AM, Geoffrey B. Steinhart <gsteinh...@lssu.edu>wrote: > I like to use the program ImageJ for analyses like this. You do need some > sort of scale to establish area or distance, but this can be done with an > object of known length that appears in the image. I have done this for > pictures in which there was not a true scale (e.g., a ruler) in the image. > You just need something that you are confident of the length. In my case, > I used eggs that appeared in the image since I had good data on average egg > diameter. You can then scale the number of pixels to a known length and, > then, calculate area of the entire photo or sections of the photo. > > ImageJ is a free download here: http://rsbweb.nih.gov/ij/ > > > Geoffrey B. Steinhart > > Assistant Professor and Co-director of the Aquatic Research Lab > President-Elect, Michigan Chapter of the American Fisheries Society > Lake Superior State University > School of Biological Sciences > 650 W. Easterday Avenue > Sault Ste. Marie, MI 49783 > phone: 906.635.2093 > web: http://www.lssu.edu/faculty/gsteinhart > > > > > On Jun 22, 2010, at 12:00 AM, ECOLOG-L automatic digest system wrote: > > > Date: Mon, 21 Jun 2010 15:31:10 +0100 > > From: Beth Strain <strain.b...@gmail.com> > > Subject: Photo analysis question > > > > Dear Ecology List Server > > I have recently been given a set of photos which I would like to > > convert into densities of species. The photos were taken haphardly but > > do not contain a quadrat or transect. The photos cover a 1-2 m area. I > > wanted to ask if anyone had any suggestions about how to calculate the > > area of the photo. > > Thanks for your help > > Beth Strain. > -- Malcolm L. McCallum Managing Editor, Herpetological Conservation and Biology 1880's: "There's lots of good fish in the sea" W.S. Gilbert 1990's: Many fish stocks depleted due to overfishing, habitat loss, and pollution. 2000: Marine reserves, ecosystem restoration, and pollution reduction MAY help restore populations. 2022: Soylent Green is People! Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message.
