Is it plausible to use NDVI along with other regular bands for image classification related data processing? Recently, I came across a comment that RED and NIR band might interfere with NDVI or vice versa during the processing. I am working on a project where I want to classify healthy and stressed crop patches using satellite imagery, and I am using all four bands (RGB and NIR) along with NDVI to train the model and classify the satellite images. For the classification, I am using the Forest-based Classification and Regression tool.
Hi Muhammad,
not sure if I get this ... but NDVI is a 'derivative' of the red and the NIR band, calculated as : NDVI = (NIR - Red) / (NIR + Red)
This results in values between 0.0 and 1.0 ... and is then often used together with colormaps/colorramps to visualize.
So, as you write above, 'the RED and NIR band might interfere with NDVI and vice versa' ... they are essentially 'dependant variables'.
Regards
Guenter
Hi Guenter
Yes, they are mainly 'dependent variables'. And my question was that if we use those together, i.e., Blue+Green+Red+NIR+NDVI for classification, does that pose any problem in our methodology or interfere with the analysis?
I have used Blue+Green+Red+NIR+NDVI as a combination of training rasters for healthy and diseased plants in the crop field and obtained a high and consistent accuracy (high kappa as well) of the classification. However, when I used NDVI alone and the RGB NIR separately, classification accuracy decreased.
Thanks
Hi again Muhammad,
to reply to this with a sound statistical/mathematical answer is beyond what I remember from those disciplines. If the results you get are consistent and verified by Ground truth ... I'd consider it proof enough
Regards
Guenter
Yes, you are right. Also, as I am using Random Forest, Multicollinearity does not affect prediction accuracy. Thanks, Guenter.