Re: MID proposal

On Sat, Nov 01, 2003 at 11:50:06PM +0100, Arpi wrote:
> > > Probably you will ask about the sense of this whole partial mpi stuff:
> > > it has not much sense currently, but we could have some filters/decoders
> > > which will support partial decoding / filtering.
> > 
> > This is NOT a clean way to do it. It's very limited (forces you to
> > only have one rectangle) and also forces all filters to support this
> 
> agree. x,y must go, it's unused in g1 too
> in my original plans (for g1's vf) it was for crop/expand stuff, i wanted
> to implement crop/expand by just changing those fields... was bad idea
> 
> > bloated ugliness of working on partial images explicitly. I have a
> 
> sure. we need well working slices, with x and w parameters (not y-only as in
> g1)

Yes, perhaps. I don't see how slices will help performance much if you
do them in a strange order tho. Anyway slices aren't really related to
this mess in mp_image.

> > much better design for new vp layer:
> > 
> > Let's say you want to blur a small rectangle of your picture. Here's
> > how the filter chain works:
> > 
> > 
> > vd ----> vf_subfilter ----> vo
> >             |   ^
> >             |   |
> >             V   |
> >            vf_blur
> 
> huh

Just a cool example of nonlinear filter chains. The (hypothetical)
vf_subfilter attaches an entire chain to itself at both ends to allow
you to apply filters to just a part of an image.

Rich