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[martijn at scanner.frw.uva.nl]

The problem described here can be solved in two ways: one is to calculate 
the pixel size from the scales of the original photograph and the scan 
and the resolution of the scan, the other is to rectify the photographs 
so they are georeferenced, then see what the cell size is with the 
g.region command.

P. Martijn van Leusen
Institute of Prehistory, University of Amsterdam   martijn at scanner.frw.uva.nl


On Wed, 29 Jun 1994, CHALLA SRINIVAS REDDY wrote:

> We scanned some aerial photos at different scales,like 100%,120%,150%.
> We know the scale at which the aerial photographs were taken. Is there
> any provision in GRASS to directly get the resolution of each pixel.
> Actually what does the d.measure do. what it represents, I mean which scale, 
> how can we incorporate those, with the actual scale at which the
> photos were taken and the scanned scale.
>        In a crude way we can do like this. We know the #of rows & cols    
> and the scale. we can findout actual measure on the ground since we
> know the scale. If we divede the total measure(rowwise & col wise) by
> the #of rows and #of cols, I think we will get each pixel resolution.
> I'm i in right direction.
> All suggestions and ideas are appreciated, thanks
> srinivas challa
> 99chall2 at lab.cc.wmich.edu
> 
>