midopt
midopt


Author Comment Last activity Moderation
Corymbia " Hi Chris, Thanks for your answer! Very helpful. 1) Regarding the reflectance targets. I bought a dozen of ceramic tiles in different colours (inc..." | Read more » over 5 years ago
cfastie " You are correct that your multi-day observation will present some problems. It is possible that doing a custom white balance on each day will comp..." | Read more » over 5 years ago
Corymbia " Hi Chris, Many thanks. I managed to get a DB660/850 filter and should have my camera (Olympus E-M10 Mark II) converted this week. It did cost an a..." | Read more » over 5 years ago
cfastie "The primary advantage of dual band filters is that they pass much narrower bands of wavelengths than red or blue filters (which also pass NIR). Th..." | Read more » over 5 years ago
Corymbia "Hi, thanks for the post. I'm planning to re-convert my NIR-adapted camera (currently with a blue filter) due to its rather poor performance in dete..." | Read more » over 5 years ago
nedhorning "For the most part I am not able to reliably and accurately validate NDVI calculations. To validate results you would need to have targets with know..." | Read more » about 6 years ago
Aman007 "How you are validating the NDVI calculation " | Read more » over 6 years ago
suman "Hello Ned, I tried using different exposure settings now, and its working, the pixels aren't saturated anymore. Thank you so much for your prompt ..." | Read more » almost 7 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 » almost 7 years ago
suman "Thank you so much for your prompt response Ned... " | Read more » almost 7 years ago
suman "Ohh I get it now. Actually the data has 3 calibration target, but i plan to increase it to 5 targets. I also wanted to know, how i can manually me..." | Read more » almost 7 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 » almost 7 years ago
suman "Dear Ned Horning, I calculated image calibration coefficients, using the reflectance data from department's spectrometer and 3 calibration targets..." | Read more » almost 7 years ago
cfastie "The photos were processed with the Photo Monitoring plugin for FIJI which has a complete users guide. If you have any questions you can describe an..." | Read more » almost 7 years ago
saangpe "You could give more details about how to process the images with Fiji and tried to replicate this but I can not make the results conform to the sca..." | Read more » almost 7 years ago
rs806 "Okay thanks Ned! I had been wondering about the structure of the csv file since, judging from the script, it had quite a few columns of information..." | Read more » over 7 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 7 years ago
rs806 "@nedhorning Hello Ned thank you for posting the R script. I'm finding it helpful to understand the process by going through the script itself. I wa..." | Read more » over 7 years ago
cfastie "In single-camera NIR systems with a filter that blocks all red or blue, the camera can be adjusted to emphasize the color channel capturing NIR. Th..." | Read more » over 7 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 » almost 8 years ago
carolccarvalho "Hello, @nedhorning, for the Rosco Roscolux #2007 Storaro Blue Gel Filter, with the following datasheet Could I just use the visible reflectance ..." | Read more » almost 8 years ago
Davidkao "Thank you very much for the advice Chris and Ned, I have learned a lot. I will continue to this research, so if possible if I encounter any problem..." | Read more » almost 8 years ago
cfastie "David, When using a blue (#2007) filter, the red channel records NIR and the blue channel records visible blue light which is used to compute NDVI...." | Read more » almost 8 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 » almost 8 years ago