[GRASS5] resampling method

[Glynn Clements]

Helena wrote:

> > can someone (quickly) explain how raster resampling is done when the
> > region's resolution changes? 
> 
> This is from the GRASSbook p. 98
> 
> When resampling from lower to
> higher resolution, the high resolution cells are assigned the same
> values as the cell within which they are located. When
> resampling from higher to lower resolution, the low resolution cell is
> assigned the value of the high resolution cell which is located the
> closest to its center (nearest neighbor). 

The first part of the above could be omitted. Resampling works the
same way regardless of whether the destination resolution is higher or
lower than the original resolution. I.e. the source cell which is
chosen is that which contains the centre of the destination cell.

Note that, when resampling from lower to higher resolution, a
destination cell isn't guaranteed to be entirely contained by a single
source cell unless the scale factor is an integer.

-- 
Glynn Clements <glynn.clements at virgin.net>