Re: Scaling icons

[Owen Taylor <otaylor redhat com>]

On Fri, 2003-05-16 at 02:33, J. Ali Harlow wrote:
> On 2003.05.15 23:44 Owen Taylor wrote:
> 
> [snip]
> 
> > What I'm thinking of doing
> > (image_size = MAX(image_width,image_height):
> > 
> >  - For "fixed" size icons, don't scale
> > 
> >  - For "Scalable" icons, load them at a scale of
> >    desired_size / dir_size. If dir_size isn't set (the icon
> >    theme spec requires dir_size, but I bet some KDE themes will
> >    omit it) load them at a scale of desired_size/image_size.
> > 
> >  - For "Threshold" icons, if desired_size - dir_size > threshold
> >    load at a scale of desired_size / dir_size, otherwise don't
> >    scale.
> > 
> >  - For unthemed icons, adopt the nautilus algorithm: scale
> >    by desired_size / image_size if image_size > MIN_SIZE,
> >    otherwise don't scale. Probably use the nautilus MIN_SIZE
> >    value of 53 for lack of anything better.
> > 
> > Does this make sense?
> 
> All apart from the last one, yes.
> 
> Can you explain the rationale for when scaling is applied in
> unthemed icons? Do we know why nautilus does it this way?
> 
> My first instinct would be to decide when to scale based on
> desired_size / image_size, eg.,:
> 
> don't scale iff 1/n < desired_size / image_size < n
> 
> where n might be something like 2.

Alex may remember better than I do, but I think the reason that
this was added to nautilus was that problems appeared with
small icons being scaled to large sizes, which typically
looks hideous. You can always scale down and things just get
a little bit fuzzy, scaling up is more problematical.

Your probably right that basing on the size rather than scale factor
doesn't make a lot of sense; so perhaps a rule along the lines
scale only if desired_size / image_size < 1.5 makes sense.

Or perhaps we just shouldn't scale unthemed icons at all.

Regards,
					Owen