bug#47043: 27.1; transparent PNG image scaled larger may be blurred

[Lars Ingebrigtsen]

ynyaaa@gmail.com writes:

> When a transparent PNG image is scaled larger, it may be displayed as a
> blurred image.
>
> The attached image transparent3.png is a green square with red dots.
> Its alpha values change one by one from left to right with step 1.
> transparent4.png is a similar image whose alpha values are floored into
> multiples of four.

In Emacs 27.1, scaling images upwards always blur them.  This has been
changed in Emacs 28.

There's further work being done in this area, though -- blurring may be
reintroduced in some use cases, but this specific problem has been
fixed, so I'm closing this bug report.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no