#51 rotated scaled rasters have edge errors

[Scott Johnston]

Rasters that have been scaled and rotated have errors
in rendering along their edges. Probably the
application of affine transform has an off-by-one error
when resampling values from the input image, so you
either get a zero-value sample, or you don't sample as
needed, or the output image is to large by one pixel,
or something like that.