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.