[Paraview] Gray scale image & calculating area with ParaView

[Gita Das]

Hallo,

I am new to ParaView & got a few questions. Any help would be greatly
appreciated.

1. When I download a 3D .mhd gray scale image with ParaView 3.2.1, it
appears in colour. The option "Map Scalars" under Display option can be
turned off with a .png image to have a grayscale one but this option
does not work (i.e. remains inactive) with the .mhd image. How can I
view my image in gray scale?
2. I need to measure/calculate different areas of a slice of a 3D mesh.
I found a filter called 
"Integrate Variables" which does something but I am not sure exactly
what it does. Can anybody give me more information on this (e.g. how it
calculates the area, the unit of measurement etc etc.).

Thank you.
 
Gita Das
Monash University
Australia