[softwarelist] Re: Halftone scanning

> A halftone b/w picture that I am trying to scan (DPlngScan 1.24) ends 
> up with a mottled appearance. 

I've had this problem, and usually manage to get a reasonable result using
the processing in DPlngScan (median or average, I forget which) sometimes
applied twice.  It loses resolution (but it's arguable whether the picture
information, as opposed to the quantisation noise, had that much anyway). 
I recall having to fiddle with the scanner resolution as well to get the
best results - probably to avoid any low spatial frequency fringing.  

The cases where I have failed have been very small images where the whole
picture was no more than 100 pixels wide.

John

-- 
John Harrison -  http://www.jaharrison.me.uk
Message sent from a British built Iyonix PC running RISC-OS 5

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