Ring Shaped ROIs

Posted by Carl Sebeny on Mar 14, 2006; 5:42pm
URL: http://imagej.273.s1.nabble.com/Ring-Shaped-ROIs-tp3703395.html

A ring shaped ROI can be defined manually by using the Oval selection
tool twice: once to create an outer circular selection and again to
subtract an inner Oval selection ("alt" key down) from the outer circle.
Processes such as "clear" and "invert" affect the pixels within the ring
shaped region bounded by the two oval selections without affecting
pixels interior to the smaller oval (the donut hole). .

 

The macro language does not seem to provide the capability to define
such a ring shaped ROI. The following statements always result in the
creation of a single oval selection corresponding to the second
"makeOval" statement:

 

            makeOval(x1, y1, width1, height1);

            setKeyDown("alt");

            makeOval(x2, y2, width2, height2);

 

The second "makeOval" statement is not affected by the "setKeyDown"
statement. The same result is obtained with and without the "setKeyDown"
statement.

 

Is there a way to define a ring shaped ROI with the macro language?

 

Carl Sebeny,

Applied Vision Company