Possible bug when a band created by bandmaths is deleted?

s2tbx
#1

hi,
I created a number of bands using bandmath. I then deleted one of them and saved my image. I am opening it again now, but I cannot open any band in SNAP anymore. I tried the same thing again with another image to test this issue, and it does the same thing and gives me an error referring the the deleted band
“Failed to open image view”, "undefined symbol "

Is there something I can do to use the image again??
Thank you
Elsy

#2

if you create a new raster band that uses the values of another, you must not delete the original raster because, by default, band maths are only stored as virtual rasters. That means that only the logical expression is saved but not the new raster itself. If you want to create a new band which is permanently independent from the other one, you have to un-check “create virtual band” in the band maths. Then save your product with File > save. Only then the raster is physically written on your hard drive and you can later remove the one it was based on.

#3

ok thank you for this important info. But, this is a big problem for the users. I understand that I might lose the new band I created if not saved as per your explanation, but not to be able to open any band of the image nor be able to use the image all together is not OK. I hope this could be considered for future versions of SNAP.

#4

In general, it is possible to open the other bands. Only if you use the virtual band in a valid expression of another band. Then opening the images will not work.

#5

I am trying SNAP 6.0, and now it is ok. If I delete a virtual band, I can still reopen the image. But, it was not possible with the previous version. I was simply losing the images.

thx for your answer.