performance problems and possible remedies?
by Yale Zhang
Hi. I'm using Inkscape to author a comic and the slow speed for certain
things is very annoying. I'm already have OpenMP turned on and using 4
1. *large blurs are slow* - I'm an expert with writing SIMD code, so I was
thinking about vectorizing the Gaussian IIR filter with SIMD intrinsics,
even though it's harder than for a FIR. But I noticed there isn't any SIMD
code in Inkscape so does that mean it's something to avoid.
I'm pretty sure no current compiler is smart enough to vectorize it, and
besides, Inkscape is compiled with -O2, meaning -ftree-vectorize isn't on
2. *when there's a large image (raster based) background - scrolling in a
zoomed region is very slow*
I compiled the latest 0.49 code with GCC profiling and it shows this:
33.98 22.47 22.47 exp2l
21.29 36.55 14.08 log2l
17.57 48.17 11.62 pow
7.12 52.88 4.71 658 0.01 0.01
6.72 57.32 4.44 563 0.01 0.01
5.51 60.96 3.64 1216 0.00 0.00
5.23 64.42 3.46 internal_modf
0.59 64.81 0.39 _mcount_private
0.41 65.08 0.27 __fentry__
0.12 65.16 0.08 GC_mark_from
0.09 65.22 0.06 5579 0.00 0.00
Geom::parse_svg_path(char const*, Geom::SVGPathSink&)
0.06 65.26 0.04 35320 0.00 0.00
std::allocator<Geom::Path> > const&, Geom::Affine const&)
0.06 65.30 0.04 8 0.01 0.01
0.05 65.33 0.03 885444 0.00 0.00
std::vector<Geom::Linear, std::allocator<Geom::Linear> > >, unsigned long
long, Geom::Linear const&)
The cost is absolutely dominated by ink_cairo_surface_srgb_to_linear() and
ink_cairo_surface_linear_to_srgb(). My first instinct was to optimize
those 2 functions, but then I thought why are those even being called every
time I scroll through the image?
Why not convert the images up front to linear and stay that way in memory?
If that can't be done, then my optimization approach is:
1. replace ink_cairo_surface_srgb_to_linear() with a simple 3rd degree
polynomial approximation (0.902590573087882 - 0.010238759806148x +
0.002825455367280x^2 + 0.000004414767235x^3) and vectorize with SSE
intrinsics. The approximation was calculated by minimizing the square error
(maxError = 0.313) over the range [10, 255]. For x < 10, it uses simple
2. replace ink_surface_linear_to_srgb() with a vectorized implementation
of pow(). Unlike srgb_to_linear(), a low degree polynomial can't be used
due to the curve having larger high order derivatives. An alternative would
be piece wise, low order polynomials.
The main question I have is what degree of accuracy is desired? Certainly,
it doesn't need double precision pow() since the input is only 8 bits! Is
+- 0.5 from the true value (before quantization) OK or do people depend on
getting pixel perfect results?
6 years, 5 months
Quality of gradients.
A few weeks ago, Tavmjong added a comment to bug #180693, asking if the
reported issue was still present with the new renderer.
I'm answering here, as I'm adding some personal comments that probably
don't belong to the bug report.
Please tell me if it's is worth that I add some of this information to
the bug report, or feel free to do it if anyone wants to.
Regarding the question,
As long as Inkscape renders at 8bpc, yes. It will still be a problem.
It's possible that some sizes and colors hide the problem more than
others, but banding will still be a problem unless images are rendered
in higher precision.
The easiest way to check this is to draw a grayscale gradient.
At 8bpc, you can't paint more than 256 shades of gray. So a 256px-wide
gradient will look ok, but as soon as you stretched that gradient to a
larger size, banding will appear.
An even more extreme example (but not less frequent) is when you also
have a grayscale gradient, but instead of going from black to white you
go from a middle gray to a lighter gray. If your gradient takes, say 50
levels out of those 256, stretching the gradient will result in severe
I don't think it's possible to address banding in 8bpc without some
form of dithering, and it looks that the current renderer doesn't apply
As I mentioned in an older comment, the best way I could find to work
around this was using the "spread" filter in GIMP, which jitters the
edges of each step of the gradient making it look smoother.
There are existing dithering algorithms that could be used too, like
floyd-steinberg, bayer, a-diher (http://pippin.gimp.org/a_dither/),
etc. but I wonder how effective would they be as we don't have a smooth
gradient as a starting point, but a stepped one.
Those dithering algos could be useful if inkscape rendered at 16bpc, to
bring down the display to 8bpc though.
At any rate, rasterizing a vector shape and applying a filter would be
prohibitively slow for large sizes so this dithering, if applied,
should be probably applied only to export, making this solution
unsuitable for on-screen representation.
Anyway, I don't think banding is too much of a problem (it is, but it's
not as severe) for screen as it is for printing.
For printing it becomes a critical issue, as other commenters pointed
Inkscape is a valuable tool for large format printing which I use
daily, and time to time I have to apply some nasty workarounds because
of this limitation.
For my professional work, the way inkscape renders gradients is a show-
stopper. The quality of my work suffers if I don't apply one of those
tedious workarounds discussed in this thread.
This bug has been reported about 8 years ago, and a lot happened since.
Maybe this time, with a new renderer there's something that can be done
to get it fixed?
Re: [Inkscape-devel] inkscape text alignment icons
by Martin Owens
Dear Claus Staedtler,
Thank you for emailing me :-) I think it's a good idea to harmonise
where possible. Inkscape's icons are a mix between our icon packs (a
tango theme and a symbolic mono-color) none of our themes have text
alignment icons (only object alignment icons).
In order to use the proposed icons they would have to be installed into
the system's icon theme.
What is the status of gimp and libreoffice regarding using system icons?
Best Regards, Martin OWens
P.S. I've forwarded this conversation to the inkscape developer's
mailing list (without attachment) we can sort that out later.
On Sun, 2016-01-03 at 11:44 +0100, staedtler-przyborski wrote:
> Dear Martin Owens,
> first a happy new year
> I recently added to the new gimp symbolic icon theme some icons.
> As my idea is that inkscape/gimp/libre-office .... use the same symbolic
> icons whenever they do the same (which is quite often not the case)
> I've made additionally made some text-alignment icons for gimp (it uses
> currently system-icon-theme, like inkscape).
> I thought inkscape might want to use these icons too (so they would be
> identical in gimp and inkscape and libreoffice).
> I've added symbolic and colored icons as svg. The symbolic icons are
> derived from libreoffice, you might want to correct the color (for what
> reason ever, inkscape uses different gray than libreoffice and
> libreoffice a different than gimp in their symbolic icon theme ...,
> maybe someday in future this will be harmonized too).
> It's up to you to make use of them or put them into trash.
> Klaus Staedtler
7 years, 1 month
by Jabiertxo Arraiza Cenoz
Hi any one could tell me if a SVG tag could contain a transform inside?
I try it on 0.91+devel, the elements are transformed but the controls
of items and the rubberband is not transformed.
To get more on the idea to know if could be done, the tool is a
rotation tool that rotate the draw from the cursor betweeen 360
degrees. There is also a angle constrain modiffier and a reset button.
Basicaly need to know if is svg compilant the transform on svg tag. And
if yes, how rotation and other trannsforms -only for info- affect to
7 years, 1 month
Create releases more regularly
by Sebastian Zartner
I initially asked at
was told to better post my request to this mailing list.
I wonder if it wouldn't be possible to create releases more regularly.
Currently there are many months or even years between each release of
Bug fixes should get out more quickly and it should be possible to try out
new features of upcoming versions. Most users don't have the possibility to
build Inkscape by their own, so they have to wait for the next release.
Unfortunately the provided development downloads are not synchronized,
hosted on different third-party web sites and out of date (currently
especially the Windows version).
So I suggest to create a (more or less) fixed fast release cycle for normal
releases (e.g. every two or three months) and periodically (e.g. every one
or two weeks) create alpha versions.
Alpha versions should be built (maybe even automatically) for all supported
OSes and hosted directly on inkscape.org.
7 years, 1 month
Impressions on Inkscape after extended usage
by Michael Grosberg
In the past several months - closer to a year, actually - I've used Inkscape
in a tight production environment almost daily. I have produced hundreds
of illustrations for a computer-based technical course. During that period
I used Inkscape 0.48.5 and lately switched to test builds and release
candidates of 0.91. All of this time I have kept a list of the problems I ran
into using Inkscape. Some are plain bugs, some are more complex problems for
which I have no idea for a solution. After testing the new version to see
whether some of these problems have gone away, I thought I might share this
document with you.
Before I go on, I just like to say that these are mostly minor points. I am
an avid user and promoter of Inkscape even though my workplace has provided
me with a legal copy of Adobe Illustrator, which I think is inferior in
ease of use. I think Inkscape on the whole is a brilliant piece of software
and I'm thankful for all your efforts. But some problem just kept popping up
again and again.
So without further ado, here's the document (it's a google doc):
Thank you for any comment or feedback you might have.
- Michael Grosberg
7 years, 1 month
Re: [Inkscape-devel] Devlibs 46 too slow
by Mark Titchener
I tried your modified build with an NVidia Quadro 1000M on Windows 7 and it
seemed okay to me.
> Le Jeudi 21 novembre 2013 9h09, Nicolas Dufour <nicoduf@...48...> a ?crit
> > I'm still investigating the issue, and just found out that the computers
> > used to reproduced the bug were all using an Intel GPU. Tests with an
> > GeForce 210 (GT218) show no slowness at all.
> Could some Windows users help me? I'd like to confirm the slowness only
> affects Intel graphics cards. Could you test a modified Inkscape binary
> (from ftp://download.tuxfamily.org/inkscape/inkscape-12282-cairo-220.127.116.11z),
> give your graphic card model and tell me if it's slow or not? IMHO it could
> be a blocker for 0.49 on Windows.
7 years, 1 month