Comments

Author Comment Last activity Moderation
nedhorning "I do not have any peer-reviewed papers related to this work - sorry. Ned " | Read more » almost 6 years ago
nedhorning "This error will occur if you run the Create NDVI from Image plugin without having an image displayed in ImageJ. I added an error message to the nex..." | Read more » over 7 years ago
nedhorning "Chris - Thanks for pointing that out. I typically clip the values so anything greater than 1 becomes 1 and anything less than -1 become -1. " | Read more » over 7 years ago
nedhorning "Hi Agustin - Your second equation is one option. Another is: (blue- (red-blue0.8)) /(blue+(red-blue0.8)) You can play around with the factor I add..." | Read more » over 7 years ago
nedhorning "Hi Agustin, The formula you wrote is what I use. I typically use the PhotoMonitoring plugin which can be found here: https://github.com/nedhorning..." | Read more » over 7 years ago
nedhorning "I don't have experience with lens mounted filters but you might get some feedback if you post your question on the plots-infrared list at http://pu..." | Read more » almost 8 years ago
nedhorning "Nice post. It would be neat to characterize some of these cameras. I made a half-hearted attempt a while back to access the necessary equipment but..." | Read more » almost 9 years ago
nedhorning "I just updated the plugin and tested it. I suggest that Andre delete his version of the download Photo_Monitoring.jar and download the fresh versio..." | Read more » about 9 years ago
nedhorning "Hi Adresc4 - I'll try to help you get the plugin working. When you are running Fiji and you click on menu bar Plugins => Photo Monitoring do you..." | Read more » about 9 years ago
nedhorning "Hi Roolark - I don't have a spectral sensitivity curve for the A2200. I've been using LEDs to get a rough idea of spectral sensitivity but that's a..." | Read more » about 9 years ago
nedhorning "Thanks for the suggestion. Maybe a teflon sheet is the way to go although I don't have any experience with these. Some of the thin sheets seem tran..." | Read more » about 9 years ago
nedhorning "I have been making some progress toward standardized calibration targets. Does anyone viewing this know of a source for inexpensive paints/coatings..." | Read more » about 9 years ago
nedhorning "Hi Thorsten, Glad to hear you're making progress. When you run the plugin are you specifying that the channel from the visible image to use for th..." | Read more » about 9 years ago
nedhorning "Chris, So many questions... I think more testing is necessary but I'll take a shot at answering each question. I'd like to hear what other folks th..." | Read more » about 9 years ago
nedhorning "If you use a dual-camera setup I suggest using an unmodified camera and a NIR-pass (visible cutoff) filter for the other camera. Some people use un..." | Read more » about 9 years ago
nedhorning "Hi Thorsten, Sorry for the confusion. Some of the non-linearity between the response of the red and blue filter should be explained in the post I d..." | Read more » about 9 years ago
nedhorning "One drawback of using the red filter is that the red part of the bayer filter passes more NIR than the blue or green parts. I'm looking into ways t..." | Read more » over 9 years ago
nedhorning "I'm curious why you need at least 3 bands for automated classification. I don't have a specific classification task in mind. In general I'm working..." | Read more » over 9 years ago
nedhorning "That's a good observation. The hotspot in these test images would tend to be toward the bottom around the shadow from Chris' head since that's wher..." | Read more » over 9 years ago
nedhorning "If it's sunny tomorrow I'll be out with the wood, tar paper and other things. With a little luck I'll have a research note before the end of the we..." | Read more » over 9 years ago
nedhorning "I got a 3" x 3" Wratten 25A gel filter on ebay for $10. There's a lot left over if you want to try it. " | Read more » over 9 years ago
nedhorning "Chris - It's interesting that you find that the Canon Powershots don't record much NIR in the blue channel. I found just the opposite - that the bl..." | Read more » over 9 years ago
nedhorning "Thanks for your comments. I am rethinking the idea that a blue filter is sensitive to chlorophyll absorption. Blue wavelengths have similar reflect..." | Read more » over 9 years ago
nedhorning "You could try to use some of these for calibration using Landsat imagery to estimate NDVI. " | Read more » over 9 years ago