[R-sig-Geo] Problem with ignoring background value

[Ophelia Wang]

Hi all,

Thanks for all the responses. I finally fixed the problem by creating a binary
mask that sets the aerial photos as 1 and the white background (layer 1=255,
layer 2=254 and 255, layer 3=255) as 0. I then used the mask function in Erdas'
utilities to mask out the unwanted background.

Ophelia