I am using mobius point and shoot camera and customized white balance setting (R-250, G-...
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by Muneeswaran |
August 26, 2019 10:20 |
I am using mobius point and shoot camera and customized white balance setting (R-250, G-500, B-900). It it still shows blue values ( see the rooftop of the shops). What could be the problem here. How to reduce the blue from the image?
I think this is appropriate for red-filtered #Infragram imaging -- if you upload to https://publiclab.github.io/infragram/, you get:
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@Warren Thanks for the quick reply. A person under the tree and the rooftops also falsely classified. How to reduce the noise? Is there a way to improve the results?
Ah, well, the NDVI algorithm only compares infrared and visible light, so there are plenty of materials that have high NDVI values, but aren't productive vegetation. Plastics, nylons, etc can have such colors, which is probably what we're seeing in your photo - plastic tarps or roofing materials and people wearing synthetic textiles. You can read more at #ndvi - i hope that helps!
@warren is correct that some synthetic materials reflect a lot of NIR and not much red, so NDVI computes to a high value (NIR-red will be similar to NIR+red so NDVI will be close to 1.0).
How did you decide to use the setting (R-250, G-500, B-900)? I used 310, 500, 700 with a red filter (Wratten 25, see https://publiclab.org/notes/cfastie/04-26-2014/mobius-ndvi). What filter are you using?
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Thank you so much @warren @cfastie !
@cfastie I am using mobius actioncam. So I am using modified mobius camera from public lab. i have read some manuals here and experimented myself and finally settled with (R-250, G-500, B-900). Do you have any suggestions?
Can I use the infragram.org for my thesis? Thanks!
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