# Dot shading a.k.a. Stippling effect [duplicate]

I am trying to convert grayscale images to black and white, where I hope to have certain artistic effect, called stippling:

I have tried two methods; dithering (with ColorQuantize)

and a stochastic method, where the probability of a pixel being black is proportional to the darkness of corresponding picture:

The image I applied this to is the following:

So, the dithered image is "too regular" in some sense and seems to be too local, there is too much white on the top.

The stochastic version is too irregular; real randomness can give clusters, which is undesirable in this case. The artistic picture above have much fewer clusters of dots/pixels, and gives a nice uniform distribution in areas of similar shade. So, what I seek is something between the dithered and the stochastic version, where the dots are all somewhat "repelling".

• A related topic you may check is Artistic image vectorization mathematica.stackexchange.com/questions/8507/… – s.s.o Mar 1 '14 at 22:40
• Stippling applied to profile images: 8716. This is a possible duplicate but I can't decide. – C. E. Mar 1 '14 at 22:41
• This would be the actual duplicate, as it's about achieveing the exact same effect: mathematica.stackexchange.com/q/21240/12 I haven't voted to close yet because you seems to have already done something similar to that, but you're looking for better quality dithering. – Szabolcs Mar 1 '14 at 22:45
• Ah, cool! I had some feeling I might have seen it somewhere, so yes, it is perhaps best to close this. Thanks! – Per Alexandersson Mar 1 '14 at 22:54
• This is NOT a duplicate of 21240, which is about 3D geometric figures only. The OP is asking about 2D grayscale images. – Tyler Durden Oct 1 '14 at 5:29