Re: Backend and non-backend (was Re: Stencil bounding box)

[Han-Wen Nienhuys]

David Feuer schreef:
> On 5/1/06, Johannes Schindelin <address@hidden> wrote:
>
> > You cannot just compare PNGs. The really important information is: where
> > is the object, not: what color is that pixel. Just think about the
> > consequences of a small adjustment of the position. The difference of the
> > PNGs is potentially quite large, even if the difference of the 
> > location is
> > quite small.
>
> I'm not convinced.  What if you apply a slight blur to both images and
> then subtract them?

How will you deal with two images that have different sizes? What will 
happen if the entire 2nd image is shifted vertically and horizontally by 
two pixels. This typically gives a huge difference (all staff lines and 
stems will no longer overlap), but there really is (almost) no change in 
formatting.


--

Han-Wen Nienhuys - address@hidden - http://www.xs4all.nl/~hanwen

LilyPond Software Design
 -- Code for Music Notation
http://www.lilypond-design.com