I can't do ndvi for Landsat8 satellite image

Good day to everyone. I just started Matlab and I am facing NDVI problem.ndvi = (NIR - R) ./ (NIR + R) I know the code but I can't define R and NIR I will be working on the Landsat8 image. Please help. Thanks in advance.

Answer 1

[Image Analyst]

Somehow you need to read in the band images. For example, can you use multibandread()?

[Yavuzhan Çepni]

honestly i don't have much idea ...

[Yavuzhan Çepni]

I downloaded an image for a specific date from USGS. 12 photos were downloaded. Then I read 1 picture. I read the tapes I should do and know (NIR-R) ./ (NIR + R) but I can't find anything about the rest.

[Yavuzhan Çepni]

[Image Analyst]

So did you extract them from the archive into individual TIF images on your drive? They look really big so they may be multi-page TIFF images that you have to use read(frameNumber) with, instead of imread() like would work with a single image.

[Yavuzhan Çepni]

sorry for writing late I looked again and the red band 4 for Landsat8 and 5 for nir but when I do this it gives error (:,:, 4) or (:,:, 5) what could be the reason for this?

[Image Analyst]

It's not a 3-D image. Try

grayImage = imread(fullFileName);
[rows, columns, numberOfColorChannels] = size(grayImage)

What do you see in the command window?

[Image Analyst]

Maybe the txt file will tell you what band/image is what wavelength. What's in it? Can you attach the txt file? Or else ask the owners of the site.

[Yavuzhan Çepni]

Thank you very much, you took your time, but I took care of it. There are already 12 tapes in the folder, all completed one by one. Thank you so much.

Answer 2

[Yavuzhan Çepni]

Answer 3

[Yavuzhan Çepni]

[Yavuzhan Çepni]

it happend like that

[Image Analyst]

It's just a regular gray scale image. So my answer above should work.

[Yavuzhan Çepni]

'For example, can you use multibandread()?' is this?

[Image Analyst]

No - just use

grayImage = imread(filename)

[Yavuzhan Çepni]

Yes I did this, but it still fails when defining tapes. Sorry, I wasted your time but I couldn't figure it out.

[Image Analyst]

What does defining tapes mean? You used imread() to read it in to a variable and that worked. So what is failing?

[Yavuzhan Çepni]

I have to calculate Ndvi (NIR-R) / (NIR + R) but I cannot define these two bands. I also researched and found the group values ​​4 nir 5 for red, but it does not work.

[Image Analyst]

You need a dot before the slash:

Ndvi = (NIR - R)  ./ (NIR + R);

[Yavuzhan Çepni]

yes, but the real problem is I can't identify the R and NIR bands, so I can't do that.I tried it many times but it does not.