No subject

in the image to be covered by the watershed labels. In other words,
you want the labels to exactly cover pixels that lead to a mimina. Is
that right?

Kishore



On Wed, Feb 17, 2010 at 6:34 PM, Luis Ibanez <luis.ibanez at kitware.com> wrot=
e:
> Lynx,
>
> Could you post in a public web site a graphical illustration
> of the image process that you are looking for ?
>
> Your description of the problem is not yet clear enough for
> us to be able to give you a good advice.
>
> It will be useful to see a screenshot of your input image,
> and also a diagram of what you would like the output image
> to be.
>
>
> =A0 =A0Thanks
>
>
> =A0 =A0 =A0 =A0 =A0 Luis
>
>
> -------------------------------------------------------------------
> On Wed, Feb 17, 2010 at 3:08 AM, =A0<lynx.abraxas at freenet.de> wrote:
>> On 17/02/10 08:37:54, Richard Beare wrote:
>>> I don't think I understand your problem fully, but here are some
>>> things you could try.
>>
>> Thanks =A0Richard =A0for =A0Your =A0answer. =A0I =A0know =A0about the ge=
neral way of doing a
>> watershed separation. The thing is I have a fully computed image =A0with=
out =A0any
>> nois.
>> And =A0now I'm looking for a filter result that not only labels but also=
 acts as
>> a mask. I have local minima in my image and I need to label =A0the =A0re=
agions =A0in
>> which =A0each =A0minimum =A0is =A0the =A0only =A0and a global one. I wan=
t those regions to
>> extend as far as the "depth" of the point from which =A0on =A0a =A0pool =
=A0of =A0another
>> minimum =A0would =A0start flowing into the other. If I'm not mistaken th=
ose points
>> would be saddle points.
>> From my unterstanding of water shed the filter floods each individual po=
ol and
>> introduces =A0water =A0sheds =A0as soon as the pools would flood another=
. I want the
>> watershed filter to stop flooding those pools at that point and just kee=
p =A0the
>> so far labeld ragion in which only one definit minimum exists.
>>
>> Is =A0it =A0possible =A0to =A0introduce =A0this flood-stop-condition int=
o the water shed
>> filter?
>> Or can the same result be achieved with the fill holes filter as =A0I =
=A0discribed
>> in my previous mail?
>>
>> Many thanks for any help or hints about this.
>> Lynx
>>
>>
>>
>>>
>>> It sounds like you are trying to label darker regions. A standard
>>> morphological watershed (in review section of ITK, otherwise on IJ)
>>> will do this. Watershed labels don't overlap, due to the method of
>>> construction. However if you simply apply the watershed to the raw
>>> image then you'll get a label for each minima, including all the
>>> noise. Usually you'll want to do some preprocessing to reduce the
>>> number of minima or find markers somewhere in the basins that you're
>>> actually interested in. If you can reliably find such markers then you
>>> can use a marker based watershed, which will only produce as many
>>> labels as you have markers.
>>>
>>> On Wed, Feb 17, 2010 at 12:45 AM, =A0<lynx.abraxas at freenet.de> wrote:
>>> > Hello!
>>> >
>>> >
>>> > I'm =A0looking =A0for =A0a =A0filter =A0who's result is that of a wat=
er shed filter that
>>> > would stop filling basins as soon as a water shed =A0would =A0be =A0i=
ntroduced. =A0The
>>> > result =A0would =A0be =A0a =A0label =A0for each marker (eg. local min=
imum) but the label
>>> > would only be as big as the "natural" basin. So the =A0labels =A0woul=
d =A0only =A0just
>>> > touch each other.
>>> > From =A0the =A0description =A0of the fill-holes-filter I'm not sure i=
f that is doing
>>> > what I'm looking for. I tried:
>>> > HMinimaImageFilter(float-image)
>>> > GrayscaleFillholeImageFilterr(Hminima-result)
>>> > SubtractImageFilter(Hminima-result,fillholes-result)
>>> > BinaryThresholdImageFilter(Substract-result) #bg=3D=3D0 fg everything=
 except 0
>>> > ConnectedComponentImageFilter(threshold-result)
>>> >
>>> > But the result is not as expected.
>>> > For one I wonder how I can achieve a threshold as fg is everything ex=
cept 0.
>>> > Second the subtraction does not yield 0 any where. Why that? Is this =
a rouding
>>> > error problem?
>>> >
>>> > Is there a better way to achieve this goal?
>>> >
>>> > Many thanks for any help or hints
>>> > Lynx
>>> >
>>
>>
>> _____________________________________
>> Powered by www.kitware.com
>>
>> Visit other Kitware open-source projects at
>> http://www.kitware.com/opensource/opensource.html
>>
>> Kitware offers ITK Training Courses, for more information visit:
>> http://www.kitware.com/products/protraining.html
>>
>> Please keep messages on-topic and check the ITK FAQ at:
>> http://www.itk.org/Wiki/ITK_FAQ
>>
>> Follow this link to subscribe/unsubscribe:
>> http://www.itk.org/mailman/listinfo/insight-users
>>
> _____________________________________
> Powered by www.kitware.com
>
> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
>
> Kitware offers ITK Training Courses, for more information visit:
> http://www.kitware.com/products/protraining.html
>
> Please keep messages on-topic and check the ITK FAQ at:
> http://www.itk.org/Wiki/ITK_FAQ
>
> Follow this link to subscribe/unsubscribe:
> http://www.itk.org/mailman/listinfo/insight-users
>