[postgis-devel] [raster] Implementations of rotation and pixel size.

[Bryce L Nordgren]

On Tue, Sep 13, 2011 at 9:58 AM, David Zwarg <dzwarg+postgis at azavea.com> wrote:
> Bryce,
>
> That's a great idea. I had some questions about it, and I think it'll be
> helpful for folks seeking to understand the worldfile and affine
> transformations. I know it wasn't straightforward, and it took me a minute
> to wrap my head around it (even then, I may not have gotten it 100% right,
> as you have noticed).  As a wiki page, it would be a great resource.

I wrote up a page on how to calculate the coefficients given the
"pure" operations: rotation, scaling, shearing, etc. Edit away or ask
questions..

http://trac.osgeo.org/postgis/wiki/DevWikiAffineParameters

Bryce