How to change the example Qt5 application "tablet" into 16 bit Grayscale ?

[Ajith_P_V]

Hi all,
Thank you for all your wonderful support here in Qt forum.
After compiling the Qt5 source I got example applications and I took tablet application for my experiments. the example tablet application is in colour mode but I want to do it with 16 bit Grayscale mode.
Could anyone tell me, how I can change the colour tablet application into Grayscale mode quickly?

Looking forward to your support...
Thank you in advance,
Ajith P V