X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?p=xscreensaver;a=blobdiff_plain;f=hacks%2Fconfig%2Ftessellimage.xml;h=f6e1a3caf4cddf5e860deff65993d33c51def44e;hp=78b44e98f78167634e552a1dedf94dd1a438eebc;hb=refs%2Fheads%2Fmaster;hpb=78add6e627ee5f10e1fa6f3852602ea5066eee5a diff --git a/hacks/config/tessellimage.xml b/hacks/config/tessellimage.xml index 78b44e98..f6e1a3ca 100644 --- a/hacks/config/tessellimage.xml +++ b/hacks/config/tessellimage.xml @@ -24,10 +24,16 @@ - + + + @@ -39,18 +45,21 @@ <_description> -Converts an image to triangles using Delaunay tessellation, and -animates the result at various depths. +Converts an image to triangles using Delaunay tessellation, or to +polygons using Voronoi tesselation, and animates the result at +various depths. -More triangles are allocated to visually complex parts of the image. +More polygons are allocated to visually complex parts of the image. This is accomplished by first computing the first derivative of the image: the distance between each pixel and its neighbors (which is -essentially edge detection or embossing). Then the Delaunay control -points are chosen by selecting those pixels whose distance value is -above a certain threshold: those are the pixels that have the largest -change in color/brightness. +essentially edge detection or embossing). Then the Delaunay or +Voronoi control points are chosen by selecting those pixels whose +distance value is above a certain threshold: those are the pixels that +have the largest change in color/brightness. https://en.wikipedia.org/wiki/Delaunay_triangulation +https://en.wikipedia.org/wiki/Voronoi_diagram +https://en.wikipedia.org/wiki/Tessellation Written by Jamie Zawinski; 2014.