Comments

Author Comment Last activity Moderation
nedhorning "Here are a couple ways to do this. One is to use two cameras mounted as close as possible to one another with the shutter release synchronized to b..." | Read more » over 3 years ago
nedhorning "It's worth testing but those cards you link to look promising. From my experience it's the bright target that is more of a problem than the dark ta..." | Read more » about 4 years ago
nedhorning "Hi Jeff - I wasn't sure if you mean varying over time or over the surface. Over time both will vary but from my experience they seem fairly stable ..." | Read more » about 4 years ago
nedhorning "Yes - the author contacted me shortly before posting the blog " | Read more » almost 5 years ago
nedhorning "Setting up and running an integrating sphere is within your reach for a 12 week course as long as the equipment is working and you have access to s..." | Read more » about 5 years ago
nedhorning "Hi dannysmith - I’m glad to hear the note was useful to get you started. I find it helpful to plot both red and blue channel regressions but I expe..." | Read more » about 5 years ago
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 » over 5 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 5 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 5 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 5 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 5 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 » almost 6 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 » almost 6 years ago
nedhorning "I do not have any peer-reviewed papers related to this work - sorry. Ned " | Read more » almost 6 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 » almost 6 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 » about 6 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 » about 6 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 » about 6 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 » over 6 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 » over 6 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 » almost 7 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 » about 7 years ago
nedhorning "Hi - For Fiji installation instruction you should look at the Fiji website: http://fiji.sc/Fiji Keep in mind that you will need to install an older..." | Read more » about 7 years ago
nedhorning "The current version of the plugin only outputs index (NDVI and DVI) images. The plugin only calibrates two bands, a visible and a NIR band and two ..." | Read more » about 7 years ago