I meant 2R,2G,2B,2A images, i.e. 8 bit per pixel. That was my misreading - it is actually 2 bytes per channel, (I'm used to image color depths being quoted in b

I meant 2R,2G,2B,2A images, i.e. 8 bit per pixel. That was my misreading - it is actually 2 bytes per channel, (I'm used to image color depths being quoted in bits.) I need to read more carefully, sorry.