Extract black and white image from android camera's NV21 format

Question

I have done some google-ing around and couldn\'t find enough information about this format. It is the default format for camera preview. Can anyone suggest good sources of i

Answer 1

The data is in YUV420 format.
If you are only interested in the monochrome channel, i.e. "black and white", then this the first width x height bytes of the data buffer you already have.
The Y channel is the first image plane. It is exactly the grey/intensity/luminosity etc. channel.