Bad png export of some svg filters at high resolution

[ivan louette]

Exporting filtered images to png at 96 dpi works right, but at highest resolutions some details are lost for some filters apparently because of an unuseful or wrong resampling.

I join an svg file including a filter intended to draw the edges of an image and the three exported results at 96, 150 and 300 dpi.

The problem could be caused by the use of Convolve matrix or a combination of it with some other primitive.

ivan

[ivan louette (ivan-louette)]

I noticed the same lost of quality while creating bitmap copy or even while zooming in the filtered image.

[ivan louette (ivan-louette)]

This issue is specific to filtered objects. If you create a 96 dpi bitmap copy of a filtered object and then create a new copy of the copy at higher resolution or export it at high resolution or zoom in, no problem.

[jazzynico (jazzynico)]

Confirmed on Windows XP, Inkscape build 21236 and 0.46.
I've removed the blur primitives, and it appears that the details are very thin at high resolution. So thin that they seem to be completely smoothed by the blur primitives.

[jazzynico (jazzynico)]

I've just found this link: http://wiki.inkscape.org/wiki/index.php/Filter_Effects
feConvolveMatrix has a "produce resolution-independent results" TODO item. Probably the cause of this bug.

[Beluga (buovjaga)]

Still repro.

Arch Linux 64-bit, KDE Plasma 5
Inkscape 0.92pre1 15054 (GTK3)