remove many small black spots

[Merlin Verdecia]

I would be very grateful if someone could explain to me how to extract the blood vessels from the image of the attachment number 1 because I have tried and I get the image of the attachment number 2 which has many small black
 spots.How I can remove these black spots?
thank you very much

[dscho]

Hi Merlin,

On Sun, 10 Jul 2011, Merlin Verdecia wrote:

> I would be very grateful if someone could explain to me how to extract
> the blood vessels from the image of the attachment number 1 because I
> have tried and I get the image of the attachment number 2 which has many
> small black spots.How I can remove these black spots?

I would suggest to think about the task differently. It is not so much
that the black spots are hurting, but that the structures of interest are
not pronounced enough.

Even after background removal, it seems that you need some algorithm that
pronounces elongated structures. You might want to try the Tubeness
filter:

        http://www.longair.net/edinburgh/imagej/tubeness/

or the Linear Kuwahara filter:

        http://fiji.sc/Linear_Kuwahara


or the Frangi filter:

        http://fiji.sc/Frangi

If none of them works, you might want to give Curvelets a try.
Unfortunately, I am not aware of any implementation in ImageJ, but there
is a Matlab toolbox (behind a registration wall) here:

        http://curvelets.org/

Ciao,
Johannes