Login  Register

Re: ROI defined by two parallel lines

Posted by dscho on Jan 12, 2013; 3:41pm
URL: http://imagej.273.s1.nabble.com/ROI-defined-by-two-parallel-lines-tp5001382p5001384.html

Hi Oleg,

On Fri, 11 Jan 2013, Oleg Broytman wrote:

> I have 2 questions:
> - When I draw the first freehand line, and click the cursor somewhere
> else to draw the second line, the first line disappears.  How can I
> avoid this?

Usually, holding down the Shift key adds to the current ROI. But since you
are talking about *line* ROIs, that would not do what you want to,
since...

> - Once I have the two lines drawn, how do I define an ROI bound by lines
> that don't connect to one another?

ImageJ 1.x has no notion about line ROIs with gaps...

The closest you can get is to add the individual ROIs to the ROI Manager
(using the "t" key) before drawing the next one. If you click "Show all"
in the ROI Manager, you will see the previous ROIs in another color.

To use the ROIs for analysis, you can either select them individually in
the ROI Manager and then process the individual ROI (you can automate this
with a macro), or you can select them all and use ROI Manager's "Measure"
if that provides the analysis you seek.

Ciao,
Johannes

--
ImageJ mailing list: http://imagej.nih.gov/ij/list.html