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Comments

Author Comment Last activity Moderation
nedhorning "Hi Suman - Using Analyze => Measure should work. It's not uncommon to have high pixel values for bright targets. In fact if the exposure isn't s..." | Read more » about 4 years ago
nedhorning "Hi Suman - The values from 0 - 1 have been scaled from the original image. The reason I do this is that some image pixel values range from 0 - 255 ..." | Read more » over 4 years ago
nedhorning "Take a look at Open Data Kit: https://opendatakit.org/. I haven't used it in a couple year but know it's still being supported. " | Read more » over 4 years ago
nedhorning "How about testing it on subsets of satellite imagery? You can pick the 3 bands and the band order you want for the testing and can compare that to ..." | Read more » over 4 years ago
nedhorning "Hi Jeff - I think I might be able to help with this but I'm not sure what you are looking for. NDVI is simply an algorithm applied to two bands so ..." | Read more » over 4 years ago
nedhorning "For calibration I think the most important factor with white balance is that you keep it the same for an entire mission. An advantage to using the..." | Read more » over 4 years ago
nedhorning "Hi Suman, I haven't tried applying calibration coefficients in any sort of rigorous way to adjust white balance. All of my calibration work has bee..." | Read more » over 4 years ago
nedhorning "Hi Suman, I do not have a peer reviewed manuscript about this work so suggest citing this web page using a style appropriate for websites or blogs...." | Read more » over 4 years ago
nedhorning "Hi sujayj - I uploaded files with the target descriptions and reflectance information to my Google Drive: https://drive.google.com/drive/folders/0B..." | Read more » over 4 years ago
nedhorning "Hi jenjimah, Testing any of these and reporting back would be worthwhile from my perspective. One word of caution is that these are very bright re..." | Read more » over 4 years ago
nedhorning "I do not have any peer-reviewed papers related to this work - sorry. Ned " | Read more » over 4 years ago
nedhorning "The CSV file for the R script is different form the table in the "Improved DIY NIR camera calibration" post. The CSV file has the reflectance value..." | Read more » over 4 years ago
nedhorning "Hi Jeff - This should be the image. Let me know if this is ok or if I need to post it some other way Ned " | Read more » almost 5 years ago
nedhorning "Hi kaushalsingh – The three target reflectance values you note seem like a good choice to me. At this point I do not have study material in additi..." | Read more » almost 5 years ago
nedhorning "Hi kaushalsingh – Ait seems as if you are trying to calibrate the image using a reference target before you calculate NDVI? If that assumption is a..." | Read more » almost 5 years ago
nedhorning "Hi - Using 440nm seem reasonable but I'd probably increase the NIR value to 760nm or beyond or something like that since the peak is probably beyon..." | Read more » about 5 years ago
nedhorning "Hi David - This is an interesting project. The reflection of the glass should affect the results as long as the reflection is not in the area of yo..." | Read more » about 5 years ago
nedhorning "Hi LaPa - You can contact me at horning@amnh.org and I will send you the spectra. You can also look at this research note for links to sites with ..." | Read more » over 5 years ago
nedhorning "I have the reflectance spectral for these materials and can provide a PDF, Excel, or CSV file of the spectra if someone lets me know a good way to ..." | Read more » over 5 years ago
nedhorning "Hi Gianni, - We are working on a new python-based version of the plugs and that will have the ability to correct dual-photo setups like yours. It w..." | Read more » over 5 years ago
nedhorning "Do you know the file format of your images? I appears that ImageJ can't read them. If you send me one pair of images and I'll see if I can find the..." | Read more » over 5 years ago
nedhorning "Hi peppepegasus - I don't have a package for the Mac at this point since I don't have a Mac. You can try to follow these instructions from a prev..." | Read more » over 5 years ago
nedhorning "Here are a couple links that should help you get started: https://publiclab.org/wiki/infragram https://publiclab.org/notes/mlamadrid/12-08-2015/pho..." | Read more » over 5 years ago
nedhorning "A good way to get feedback about processing your infrared photos is to post the question with a sample image to the Public Labs Infrared Google Gro..." | Read more » almost 6 years ago