Written by Paul Bourke
The following describes and shows examples from a speckle painting technique simulating images composed of small painted pieces of tile or blobs of paint. The basic idea is to start with any computer image and recreate it using small coloured circles or randomly shaped polygons. Whatever 2D primitive is used they shouldn't overlap. The colour is derived by sampling or averaging the pixel colours within the primitives interior in the original drawing.
The results can be made to look similar to the paintings done on bark by Aboriginal Australians. The paints were mostly ochre, a clay and hydrated ferric oxide. The range of pigments were limited to light yellows to brown and red. Rare pigments such as purples were sometimes collected from the Elcho Island. Whites were recreated with huntite, calcium magnesium carbonate. Charcoal and magnesium ore were used for black. The bark was usually that of the plentiful eucalyptus tetradonta tree. The paintings were fixed using various saps but these didn't normally have any effect on the colouring.
In the next examples the original image is on the left and the computer generated image on the right. The first example uses circles and the second uses randomly sized and shaped polygons.