We've found GLA (free download from http://www.ecostudies.org/gla/) to be very useful. But we have not compared it to other programs. So we'll be interested in replies to this post.
I'd like to add two specific questions: 1) I've had problems choosing a brightness threshold with GLA, using a slider bar (determining what is considered sky vs. vegetation). When I re-analyze the same photo (or someone else analyzes it), the variation due to differences in what threshold is choosen is large relative to the size of the effects we're trying to measure. Do other software programs have an option (e.g., an image categorization algorithm) that provides more consistency? What have other people's experiences been with this issue? 2) With GLA, batch processing is not an option. I can check the specs of other programs for this option (WinScanopy offers it), but wonder how well it works in practice. We want to measure light transmission and gap sizes for hundreds of hemispherical canopy photos. Thank you. - Sara Cairns [EMAIL PROTECTED] Data Manager / Biologist NH Natural Heritage Bureau Division of Forests & Lands (603) 271-2215 x 302 www.dred.state.nh.us/divisions/forestandlands/bureaus Date: Thu, 16 Mar 2006 17:44:19 -0600 From: Luben Dimov <[EMAIL PROTECTED]> Subject: Software for hemispherical photo analyses Dear All: Would anyone recommend me a good software package for analyses of hemispherical photographs? I see a copy of HemiView 2.1 lying around, but it seems rather old. Thanks, Luben [EMAIL PROTECTED]
