Classification result and calculate area of diiferent coverage

I have done binarisation to sepate flood water with non flood area.

  1. How to calculate total flooded area in my scene?
  2. Can it be possible to demarcate specific area of my imagery and calculate the total flood affected area within that boundary?
  3. If not, how to export this file so that it can be opened in other software and do calculation?

Please reply

on the calculation of the area, please have a look here: Classified image frequencies

If you created a BEAM DIMAP product, you can go inside the data folder and directly use any img raster in a GIS software.