© 1998 by British Computer Society
Fractal Compression and the Jigsaw Property I
Department of Mathematics, Glasgow University, Glasgow G12 8QQ, UK Email: s.hoggar{at}maths.gla.ac.uk
We speed up the screening of a computer image compressed as an iterated function system (IFS) of affine transformations w1,...,wN. The idea is to avoid applying a given map to a given point if nothing new would be obtained.
Let w(x, y) be the result of applying transformation w to pixel coordinates (x, y) then rounding to the nearest integer pair, say (u, v). Then the w-jigsaw pieces w1(u, v) tile the plane. We develop a foundation of results about such jigsaws based on the coefficients defining the transformations w, and apply them to a collection of 50 IFSs. Much time is indeed saved and the method is to be pursued further.
Received March 11, 1998. revised August 4, 1998.