When using a magnifying glass, the display quality decreases with the zoom level. The image becomes increasingly blurry. This is very problematic because, for someone with a severe visual impairment, every improvement in readability is crucial.
Plasma desktop will offer an option to make the display sharper at these high zoom levels, it would be great to have something equivalent for Gnome.
This feature is now available with plasma, and it works very well (at the cost of a minor and acceptable GPU usage increase). It really helps having a sharper, more readable, display when zooming, and thus reduce visual fatigue.
Here’s the issue for it
In my understanding, this is not exactly the same problematic. In the ticket you cite, the accessibility zoom feature is used only for color filtering, and this is the positioning of certain values of fractional scaling that leads to blurry display.
In my case, this is the magnification feature of the accessibility zoom that is at stake (I use a 200% factor that avoid some kind of problems). This feature use an algorithm that alter the quality of the resulting image, whatever the magnification factor.
I opened a discussion around this 2 years ago Zoom quality vs fractionnal sclaing . Jonas Ådahl proposed a solution that would produce a 100% perfect zoom and would be the ideal one: let the a11y zoom feature affect the resolution clients. That’s what Nourish OS seems to have done, and it would be fantastic to have it in Gnome. Another solution would be to rework the resulting image in order to sharpen it and make it more readable: that’s what KDE has done, and this is clearly something that would be very good to take.
