Re: An alternative to gdk-pixbuf

On Mon, 10 Sep 2018 07:02:23 +0000
Debarshi Ray <rishi is lostca se> wrote:

On Sun, Sep 09, 2018 at 02:57:30AM +0200, Magnus Bergman wrote:
Many fields of science deal with images of multi
gigabyte sizes. Ideally any image viewer should be able to handle
these too with the right plugin (probably using GEGL in that case).
But I think the problem with large images (say 12000x12000 or so)
is giving it to the application as a pixmap. From my own tests it
seams it's fine at least as long as the images are no bigger than
the screen. So if the drawing (and implicitly also scaling) is
handed over to the loading library (which in turn might hand it
over to the plugin), this problem can be avoided.  

Even if one does decode the entire full resolution image into a tiled
data structure (say, GeglBuffer), there's no need to create a Cairo
surface for the entire image at 1:1 zoom. All that's needed is a
surface to represent the visible area at the visible zoom. That's a
lot more manageable.

Yes, exactly. Using abydos_render() that's very possible to implement by
the back end. Then trying to view larger images using gdk-pixbuf, I
didn't experience any particular problems then the image was at normal
size or zoomed in. The problem was zooming out. So I think just
creating one or two prescaled versions will get you quite far (as long
as there is no problem fitting the image into memory that is).

[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]