measure density in ribbon-like structure

[Edgar Rivedal]

Dear all
In a grey-tone image I want to draw a freehand circlular line. Then I want ImageJ to create two lines, one on the inside and one on the outside of the first line, both having the same distance from the first line. The two last lines would then create a ribbon of fixed width with the same form as the first line. Then I would like to measure integrated grey-tone density in the area (ribbon) made up by the two last lines, as well as the integrated density inside of the ribbon.

Best regards
Edgar  

[Thomas Pengo]

Hi,

have you tried:
- make your freehand selection
- Edit / Selection / Make Band: select how wide the band should be, in
pixels.
- Analyze / Set measurement: add "Integrated Intensity"
- Analyze / Measure

Is this what you're looking for?

Cheers
Thomas

On 28 June 2011 08:48, Edgar Rivedal <[hidden email]> wrote:

> Dear all
> In a grey-tone image I want to draw a freehand circlular line. Then I want
> ImageJ to create two lines, one on the inside and one on the outside of the
> first line, both having the same distance from the first line. The two last
> lines would then create a ribbon of fixed width with the same form as the
> first line. Then I would like to measure integrated grey-tone density in the
> area (ribbon) made up by the two last lines, as well as the integrated
> density inside of the ribbon.
>
> Best regards
> Edgar
>

[Edgar Rivedal]

Thank you!

Very close. However, the band is created on the outside of the selection. Is there a way to have the band appearing on the inside?

Edgar

[melkor2.0]

You could use "enlarge" selection using first a positive value, then the
same but negative, adding both to the roi manager, use the option XOR and
measure that. My problem is how to measure the perimeter of these "rings"
once you have cleared the part of the image you don't need, and remain only
that ring...
On 28 Jun 2011 09:53, "Edgar Rivedal" <[hidden email]> wrote:

[Thomas Pengo]

Well, one quick way is to first enlarge (Edit/Selection/Enlarge) by a
negative value, half the band size, then make a band with the full width.

Cheers
Thomas


On 28 June 2011 09:48, Edgar Rivedal <[hidden email]> wrote:

> Thank you!
>
> Very close. However, the band is created on the outside of the selection.
> Is there a way to have the band appearing on the inside?
>
> Edgar
>

[Edgar Rivedal]

Excellent!
Just what I wanted, thank you so much!

Edgar