Re: [ubuntu-art] Inkscape export and resizing
On Tue, 2009-04-07 at 14:22 -0700, Chris Tooley wrote: > For instance, I can draw a box in a 16x16 working area 15 pixels wide, > and center it, but the edges will look like crap - even though it's a > straight line, the antialiasing will blur the lines - due to the 15 > pixel box being defined on "half pixels". However, if I draw a 14 > pixel wide box and center it, then the icon is much cleaner. > > > i.e. at 16 pixels, with a 14 pixel box, there is a well defined pixel > on either side. So I get a clean white full pixel, instead of being > half a pixel, which inkscape then proceeds to "dirty" up with it's > valiant attempts at antialiasing. At least some of us are very aware of the importance of placing things exactly on the pixel-grid whenever possible. Still good to have an explicit description of this issue as reminder. In my example, I used rotated text and ovals to trigger anti-aliasing issues and didn't care about the grid in the few places where I could have. Things that line up with grid are less likely to gain anything from exporting to larger size and down-sampling. -- Thorsten Wilms thorwil's design for free software: http://thorwil.wordpress.com/ -- ubuntu-art mailing list ubuntu-art@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-art
Re: [ubuntu-art] Inkscape export and resizing
This is probably something completely different from this discussion, but it's something I think might be helpful...(maybe everyone already knows this) If you're working on something at 16x16 pixels, and output to 16x16, the antialiasing looks better depending upon the dimensions of your vectors and where you place them. For instance, I can draw a box in a 16x16 working area 15 pixels wide, and center it, but the edges will look like crap - even though it's a straight line, the antialiasing will blur the lines - due to the 15 pixel box being defined on "half pixels". However, if I draw a 14 pixel wide box and center it, then the icon is much cleaner. i.e. at 16 pixels, with a 14 pixel box, there is a well defined pixel on either side. So I get a clean white full pixel, instead of being half a pixel, which inkscape then proceeds to "dirty" up with it's valiant attempts at antialiasing. One could conceivably apply similar thoughtfulness to other vector/image size combinations in order to suppress "dirty" pixels. Hope I'm not blowin' smoke! ~Chris On Tue, Apr 7, 2009 at 9:43 AM, Oliver wrote: > Am Dienstag 07 April 2009 17:23:00 schrieb Thorsten Wilms: > > Hi! > > > > Some say that higher quality output can be obtained by exporting from > > Inkscape with the desired size x a-power-of-2, e.g double, fourfold or > > eightfold. > > > > It seems that is the case, but not always. > > > > I did an experiment with just black text on white: > > http://www.piccdrop.com/images/1239116989.png > > > Inkscape-Bitmapexport (180dpi) and resize it with gthumb is always the best > result. It's a harmony between sharp and smooth and craps better with one > colour to the next one. Think this is an argument for this method. Only > Inkscape in Bitmapexport fails a little bit in round things (light smooth > is > missing). > > Oliver > > > The GIMP and gThumb examples are scaled down from an Inkscape export of > > eightfold size, using Cubic interpolation in GIMP and "High-Quality" in > > gThumb, which is likely to be cubic, too. > > > > For the difference images, I used GIMP's Difference layer mode. The > > gThumb/GIMP difference is not entirely black, there are pixels with a > > minimal value, but visually, this difference is pretty much > > non-existent. > > > > > > I would like to see suggestion for how to get the worst case for > > Inkscape, where this method could shine the most. > > > > > > -- > > Thorsten Wilms > > > > thorwil's design for free software: > > http://thorwil.wordpress.com/ > > > > -- > ubuntu-art mailing list > ubuntu-art@lists.ubuntu.com > https://lists.ubuntu.com/mailman/listinfo/ubuntu-art > -- ubuntu-art mailing list ubuntu-art@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-art
Re: [ubuntu-art] Inkscape export and resizing
Am Dienstag 07 April 2009 17:23:00 schrieb Thorsten Wilms: > Hi! > > Some say that higher quality output can be obtained by exporting from > Inkscape with the desired size x a-power-of-2, e.g double, fourfold or > eightfold. > > It seems that is the case, but not always. > > I did an experiment with just black text on white: > http://www.piccdrop.com/images/1239116989.png > Inkscape-Bitmapexport (180dpi) and resize it with gthumb is always the best result. It's a harmony between sharp and smooth and craps better with one colour to the next one. Think this is an argument for this method. Only Inkscape in Bitmapexport fails a little bit in round things (light smooth is missing). Oliver > The GIMP and gThumb examples are scaled down from an Inkscape export of > eightfold size, using Cubic interpolation in GIMP and "High-Quality" in > gThumb, which is likely to be cubic, too. > > For the difference images, I used GIMP's Difference layer mode. The > gThumb/GIMP difference is not entirely black, there are pixels with a > minimal value, but visually, this difference is pretty much > non-existent. > > > I would like to see suggestion for how to get the worst case for > Inkscape, where this method could shine the most. > > > -- > Thorsten Wilms > > thorwil's design for free software: > http://thorwil.wordpress.com/ -- ubuntu-art mailing list ubuntu-art@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-art
[ubuntu-art] Inkscape export and resizing
Hi! Some say that higher quality output can be obtained by exporting from Inkscape with the desired size x a-power-of-2, e.g double, fourfold or eightfold. It seems that is the case, but not always. I did an experiment with just black text on white: http://www.piccdrop.com/images/1239116989.png The GIMP and gThumb examples are scaled down from an Inkscape export of eightfold size, using Cubic interpolation in GIMP and "High-Quality" in gThumb, which is likely to be cubic, too. For the difference images, I used GIMP's Difference layer mode. The gThumb/GIMP difference is not entirely black, there are pixels with a minimal value, but visually, this difference is pretty much non-existent. I would like to see suggestion for how to get the worst case for Inkscape, where this method could shine the most. -- Thorsten Wilms thorwil's design for free software: http://thorwil.wordpress.com/ -- ubuntu-art mailing list ubuntu-art@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-art
