Difference between revisions of "Advanced stippling"

Revision as of 17:36, 28 September 2010

<<< Generating TSP art from a stippled image || Advanced stippling

Unfortunately, there is very little in the area of ready-to-use software packages or plugins for automatically producing stippled images. While tutorials exist, they largely focus on reproducing a specific style of stippled art work (e.g., Hedcut). Such techniques are not quite appropriate to TSP art: they do not allow much, if any, control over the number of stipples used. Exising software which affords control over the number of stipples seems to be "research grade". That is, the software's primary design goal was not that of ease of use, clarity, nor robustness. With that in mind, OS X and, maybe, Windows users as well, have the option of trying out Adrian Secord's weighted Voronoi stippler [1, 2].

In the course of his researches, Adrian Secord wrote a program for producing weighted Voronoi stipplings of computer image files. Secord's program allows control of the number of stipples used as well as their diameters. See Secord's NYU research website for informtion on downloading this program,

http://mrl.nyu.edu/~ajsecord/stipples.html

What follows are some simple notes on using this program.

1. After you open an image file, it may take a while before any stippled image appears. It sometimes helps to nudge things along by selecting "Relax Points" or "Jitter" under the "Points" menu item.
2. You can control the number of stipples with the "Set num..." item under the "Points" menu.
3. The program will run for quite some time while seeming to not be doing anything. It's actually trying to refine the picture it has drawn. You can go ahead and tell it to save its work while it is working on its refinements.
4. When you have a stippling you like, use the "Save Points" item under the "File" menu. This will write a file containing (x,y) coordinates of each point and their radii. The tspart.py script can read these files as input files. No special options need be set when running tspart.py: it automatically detects the file format.
5. If you start seeing blue stipples, that means that you're allowing more stipples than needed. You can decrease the number of allowed stipples.

Notes

[*] Stippled images generated with Adrian Secord's weighted Voronoi stippler. [1] As sources are available for Adrian Secord's stippler, it's possible that the code can be built on Linux as well. Some very minor changes are needed to appease more recent versions of gcc. Contact the original author of this article for a run-down of the few minor edits needed.
[2] On OS X, when you exit the code it tends to exit ungracefully. The author of this article has rebuilt the software on OS X 10.6 and found the issue to persist.

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