Public Lab Research note


NDVI Colour Sensitivity

by bc512 | October 09, 2013 04:18 | 38 views | 5 comments | #9425 | 38 views | 5 comments | #9425 09 Oct 04:18

Read more: publiclab.org/n/9425


I am having a bit of trouble getting my end result photo as "colour sensitive" as I would like,

I have seen a few photos uploaded onto here that are very good and you can clearly see separation between Higher Photosynthesis and lower,

example this image..

Screen_Shot_2013-08-24_at_12.09.01_PM.png

my images are ending up a bit different and not as colour sensitive like this..

3.png

Im not sure if its because my image isnt a high enough quality when I export it or Stitch all the photos together. I am wondering if anyone has any advice for me to maybe make my images a bit more sensitive like the first photo I posted?

thanks


5 Comments

The NDVI image looks pretty good to me, but I don't know much about your process or expectations. Fill us in and we might be able to help (guidelines here). Also, There might be more interested eyes looking at the plots-infrared discussion forum, where it is easier for respondents to add images, etc.

It looks like the arbors are lower NDVI than the paths between them (but I am guessing about your color mapping). Is that what you would expect?

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Have you custom white balanced your Infrablue camera?

http://publiclab.org/notes/cfastie/07-17-2013/balancing-act http://publiclab.org/wiki/infrablue-white-balance

That was an issue for me.

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Hi, can you post your raw Infragram image? So we can try?

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Hello,

you can also play with the Digital Numbers focusing on the values you are interested (see histogram and min/max values), you can use many free GIS software like QGIS ( www.qgis.org) .By doing it you might stress the differences in the vegetation.

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hey warren my infragram image is posted right at the top of the page in high quality if you would like to have a go

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