plant-health
plant-health


Author Comment Last activity Moderation
cfastie "kykytos, Sorry, I am out of the business of mailing #2007 filter. We are currently testing several different filters with different cameras to choo..." | Read more » over 11 years ago
kykytos "I'd like some of the Rosco filter too. Thanks! " | Read more » over 11 years ago
cfastie "Hi jaluna, NDVI tells us something about plant health because it quantifies the difference between light that is absorbed by plant pigments and use..." | Read more » over 11 years ago
jaluna "Hello cfastie! I follow your job with interest, but there are a thing that I not understand well. You say "A filter can be used to block all red l..." | Read more » over 11 years ago
nedhorning "Increasing dynamic range will go a long way in improving NDVI results in the shadows. There are some high-dynamic-range image processing methods th..." | Read more » over 11 years ago
cfastie "Ned, your explanation suggests that exposure is critical. The shadow in the close-up is essentially the same as the ones in the gigapan - a shadow ..." | Read more » over 11 years ago
nedhorning "Great shots. The impact of shadows on NDVI will vary with the darkness of the shadow. Lower pixel values (darker shadow) will be more likely to pro..." | Read more » over 11 years ago
liz "@Jeff i really like this NDVI color gradient that replaces violet with black. " | Read more » over 11 years ago
cfastie "This set has the Rosco and the halogen. https://spectralworkbench.org/sets/show/366 " | Read more » over 11 years ago
warren "Can you link to the spectra so I can give it a try? Thanks. " | Read more » over 11 years ago
cfastie "Jeff, Your first question: I subtracted the Rosco spectrum from the halogen light spectrum, but the result made no sense at all. So I just used the..." | Read more » over 11 years ago
warren "I've been modifying lots of cameras with the new superblue filter (using the Rosco filter you sent). For those (like webcams) which don't have cust..." | Read more » over 11 years ago
PlanetenPaultje "When I went to school in 1969 (something) the physics classroom was equipped with a big slide lantern that was installed by Siemens in 1925. It got..." | Read more » over 11 years ago
cfastie "Brother Will, who sent me the lantern slides, asked a good question today: What is a lantern slide? I guess I should have assumed that many folks b..." | Read more » over 11 years ago
patcoyle "Chris, what a thoughtful and informative piece. Delightful that you also had the R. W. Wood, infrared photographs show up in your mail box. " | Read more » over 11 years ago
warren "Wow... he's a character who'd likely have gotten along with us... That's amazing that you have those plates! You said it was probably not the orig..." | Read more » over 11 years ago
warren "Apparently, from my phone, not nearly well enough. There are disadvantages to a mobile friendly website... Using baseline subtraction in Spectral ..." | Read more » over 11 years ago
cfastie "That's an excellent color table for the heat metaphor. This topic of how to display NDVI deserves much more attention. "It'd be neat to test the r..." | Read more » over 11 years ago
warren "I've been messing with different NDVI gradients, and have been trying to get one which shows "cool" colors below zero, and doesn't circle back arou..." | Read more » over 11 years ago
geobduffy "Thanks for the quick response. I'd be happy to be a Low Alt Aerial Photo Guinea Pig for testing :) " | Read more » over 11 years ago
cfastie "Ned's plugin is available under downloads here: https://github.com/nedhorning/PhotoMonitoringPlugin. I still has a bit of a learning curve but offe..." | Read more » over 11 years ago
geobduffy "Do you have a source for Ned's ImageJ plugin? I'm very curious about that. Also, I may have gotten ahead of myself with excitement...Do you think t..." | Read more » over 11 years ago
geobduffy "Thank you for sharing this information. Your results are very promising. I am struggling to come up with a way to capture imagery that can be used ..." | Read more » over 11 years ago
warren "Hi, Chris - i copied this down from YouTube but the version I got was a bit pixellated. Any way you could post the original so we can reduce copyin..." | Read more » over 11 years ago