Thresholding on gray image

I am struggling with a special thresholding problem. I have some
scanned images of randomly distributed black spots. Those spots may be
isolated or grouped, in other words, each black spot may have 0 to 6
black spots neighbors. Due to possible heavy blur during the scan,
some isolated black spots may even have gray values higher than a
white area surrounded by all black spots. This causes a headache in
thresholding. A universal threshold value could identify an isolated
black spots as bright, while mistreating a white space enclosed by
black spots as black. I am wondering if there is any effective dynamic
thresholding method could be applied to solve the problem.

Thanks,

Cindy
.

Relevant Pages

  • Re: Thresholding on gray image
    ... > I am struggling with a special thresholding problem. ... > scanned images of randomly distributed black spots. ... That is, place down a disc, ... What you have described is not Hogboms CLEAN algorithm and would not work. ...
    (sci.image.processing)
  • Re: Thresholding on gray image
    ... scanned images of randomly distributed black spots. ... A universal threshold value could identify an isolated ... Maybe an edge detection followed by a hole-fill. ...
    (sci.image.processing)