Hello, I am new to NDVI but am trying to figure out what the difference is between an NGB and NRG...
Public Lab is an open community which collaboratively develops accessible, open source, Do-It-Yourself technologies for investigating local environmental health and justice issues.
Are you interested in the difference between a blue filter and a red filter? A blue filter could be referred to as NGB (red is blocked and NIR replaces red in RGB). A red filter could be referred to as RGN (blue is blocked and NIR replaces blue in RGB). Ned has a note about why a red filter can be better for vegetation analysis: https://publiclab.org/notes/nedhorning/11-01-2013/why-a-red-filter-should-work-well-for-ndvi. Also, blue filters don't seem to work very well with small CMOS sensors which most webcams and small cameras have.
There can be a lot of NIR contamination in the red channel when using RGN filters, especially in bright tropical sun at midday. To get higher NDVI contrast, I usually subtract the blue NIR channel from the red visual channel in Fiji/ImageJ before running the NDVI calculation.
This is on a cheap action camera, maybe compact and DSLR cameras have cleaner sensors.
Are you interested in the difference between a blue filter and a red filter? A blue filter could be referred to as NGB (red is blocked and NIR replaces red in RGB). A red filter could be referred to as RGN (blue is blocked and NIR replaces blue in RGB). Ned has a note about why a red filter can be better for vegetation analysis: https://publiclab.org/notes/nedhorning/11-01-2013/why-a-red-filter-should-work-well-for-ndvi. Also, blue filters don't seem to work very well with small CMOS sensors which most webcams and small cameras have.
Chris
Is this a question? Click here to post it to the Questions page.
Reply to this comment...
Log in to comment
There can be a lot of NIR contamination in the red channel when using RGN filters, especially in bright tropical sun at midday. To get higher NDVI contrast, I usually subtract the blue NIR channel from the red visual channel in Fiji/ImageJ before running the NDVI calculation.
This is on a cheap action camera, maybe compact and DSLR cameras have cleaner sensors.
Reply to this comment...
Log in to comment
Wapmon is a wap portal where users can get access to trending videos on the internet. This is a platform that has millions of videos up for users to download.
Reply to this comment...
Log in to comment