https://bugs.kde.org/show_bug.cgi?id=509770
--- Comment #8 from Ritchie Frodomar <[email protected]> --- (In reply to Jérôme Brenier from comment #7) > (In reply to David Edmundson from comment #6) > > I don't believe it would improve accessibility, if you have impaired vision > > this becomes moot. > > > > >The use of wayland and the advances in fractional scaling seem to open up > > >possibilities for obtaining a lossless zoom, so it would be very important > > >to have it. > > > > In theory, yes. In practice some apps like Telegram that do incorrect things > > with the scaling. > > There's no requirement at a spec level for apps to draw the same contents at > > the newer scale so doing this would just break. > > I HAVE impaired vision and need to zoom in to use my computer, so my request > to improve zoom focus is not an abstract or theoretical request. > Windows or MacOS offer zooms with much higher quality, which allows me to > have less visual fatigue and more pleasant use. I would like to have the > same thing with Linux and Plasma desktops in particular. I also respectfully but wholeheartedly disagree with the "it's all moot if you're impaired enough to need that much zoom" take. The point of desktop zoom is to be able to increase the size of things on-screen until *they are* clear through your vision, that's why I use it over a screen reader. The reason macOS and Windows are able to do it with much higher quality than we are currently, is that they literally do (or, once did) use a shape-aware upscaling filter. They trade off on potential artifacting and blotchiness in images for better text clarity, since text is generally more important for us than realistic-looking photos. It's a viable solution. The problem I've been having in trying to implement it is, ironically, finding blind-accessible documentation on *what the algorithms these magnifiers use* are, and how to implement them. The closest I've found are upscaling filters geared toward pixel art that people use in the emulator scene for retro games. Things like hq4x. I just don't have the math skills to generalize them for a screen magnifier that lets you upscale by a factor of anywhere from _nothing_ to 100x. I have doubts that applying hq4x to a desktop rendered at 100x zoom is going to get us close to what the proprietary screen magnifiers are doing. I got fairly close experimenting with Sobel edge detection with the WCAG contrast measurement formula. This helped me mask out text and icons from the rest of Plasma, but that's as far as I could get. Actually identifying the shapes inside the detected edges, and filling them in with the correct colors, is a different story. The challenging part is anti-aliased text, and diagonal lines, and avoiding introducing halos and checkerboard patterns into the zoomed image. -- You are receiving this mail because: You are watching all bug changes.
