Blank in supervised classification

Optical Toolbox
#1

I’m usint SNAP software but I have met some problems relative to the Supervised Classification.

In particular, I’m working with Sentinel 2 data following these steps:

1- Resampling (output resolution 10)

2- Subset

3- Reprojection (WSG84)

Then, I create a new vector data container using vector polygons function but, when I open them, the style_css column results blank.

Moreover when I run the classification (MLC and/or MDC) the whole output image (Labeled classed) results black and in in frequency column of the Colour Manipolation panel I find a question mark.

Can anyone help me?

#2

just to go sure: You first create the vector data container and then digitize the training areas?

Can you select them as inputs in the classification module?

#3

Thank you for your prompt reply.
Yes, first I create the vector data container and then I add the vector polygons.
To reply to the second question I show you the classification screen:

Immagine1
Immagine11363×768 77 KB

#4

can you please show the VectorData tab and what it contains? You might need to make the column larger to see the full content.

#5

The vector data tab, contains all the selected polygons but the column “style_css” is empty.
I show you my screen:

Immagine1
Immagine11368×770 106 KB

#6

the style_css is not important for the classification.
Are there polygons in the water geometry as well?

#7

Yes, I have created water polygons:

Immagine1
Immagine11368×770 63.8 KB

#8

hm, the only thing that I can think of then is the input bands. Are there also other ones besides B1-B12 in the list of source bands for the classification? Maybe you should try to select only the few bands which contain image information.

#9

Dear Dr. Braun, thank you for your helpful assistance. Following your suggestion I have solved my problem (selecting only few bands…)