GNOME Bugzilla – Bug 496306
gdk_pixbuf_scale_simple() resizes when it shouldn't
Last modified: 2014-10-22 17:10:00 UTC
A call to gdk_pixbuf_scale_simple() with the GDK_INTERP_HYPER parameter for some reason ends up resizing an image, even if the size requested matches the size of the pixbuf I give it.
It's not very hard to check for it myself - but I wasted some of my time figuring out why the images look fuzzy, and I suspect I'm not the only one.
Would be good if gdk_pixbuf_scale_simple() would do a check itself.
Created attachment 111791 [details]
Contains an example of fuzziing image while 1:1 scale.
The GDK_INTERP_HYPER filter is described as follows in the documentation for gdk-pixbuf scaling functions:
This is the slowest and highest quality reconstruction function. It is derived from the hyperbolic filters in Wolberg's "Digital Image Warping", and is formally defined as the hyperbolic-filter sampling the ideal hyperbolic-filter interpolated image (the filter is designed to be idempotent for 1:1 pixel mapping).
It appears from the note in the brackets that if an image is scaled 1:1 with this filter applied, the image should remain the same.
So current behaviuor of this filter contradicts not only to the user's expectations, but also to the documentation.
look as duplicate for #80927
Yes, it seems that 80927 is origin of this bug
And bug 80927 was finally fixed today :)
*** This bug has been marked as a duplicate of bug 80927 ***