On Thu, 6 Sep 2018 at 11:40, Emmanuele Bassi via gtk-devel-list <gtk-devel-list@gnome.org> wrote: > On Wed, 5 Sep 2018 at 19:25, Magnus Bergman <magnus.berg...@snisurset.net> > wrote: >> Gegl is great for image editing. But not as much for simple viewing. > > This is debatable. If I'm viewing a 4000x4000 RGB image on a hidpi display > I'm already pushing gdk-pixbuf and cairo to their limits because of the > scaling factor applied to the window — not only the buffer gets loaded > uncompressed to allow for zooming, but the image viewer needs to render a > CPU-scaled down copy of the image.
It doesn't have to be gegl, of course, you could use any image processing library to load and scale down the images. I made a tiny image viewer based on libvips: https://github.com/jcupitt/vipsdisp-tiny It's 300 lines, but does multi-threaded, asynchronous painting of many image formats. It can display gigapixel images on very modest hardware, and it should be quick. There's a more complete image viewer here: https://github.com/jcupitt/vipsdisp That adds most of the usual navigation stuff, though it's not quite done, I must get back to it. The image display part is a widget you could easily cut out and paste into other applications. It's in C, but libvips is a GObject-based library, so it'd be easy to write in any language. Here it is displaying a 18k x 8k 16-bit TIFF: http://www.rollthepotato.net/~john/summer.png That image takes about 8s to load on this laptop. Here it is displaying a 120k x 100k pixel ndpi slide image: http://www.rollthepotato.net/~john/slide.png That image loads instantly, since ndpi supports random access and vipsdisp can just load the parts it needs to paint the screen. John _______________________________________________ gtk-devel-list mailing list gtk-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-devel-list
