Re: Clearing text from image

Posted by Rasband, Wayne (NIH/NIMH) [E] on Mar 27, 2010; 4:39am
URL: http://imagej.273.s1.nabble.com/Clearing-text-from-image-tp3688768p3688769.html

On Mar 26, 2010, at 11:09 PM, Benn, Douglas K. wrote:

> Could anybody please tell me if there is a simple way to clear a text string written as a label onto an image using drawString()  ? I tried writing the same string but with 0,0,0 as the color - I am assuming that is black. I cannot find a simple description of how overlay text is represented. I thought of importing the original image slice but this seems very clumsy so I expect there are easier ways. Also is there a description of different colors and their numeric representations?

The drawString() macro function destructively renders the text onto the image. Use makeText() and the Image>Overlay>Add Selection command to display text using a non-destructive overlay. Here is a macro that displays "Hello" in red as an an overlay, clears it two seconds later, and two seconds after that displays "Goodbye" in green.

   requires("1.43p");
   makeText("Hello", 50, 50);
   run("Add Selection...", "stroke=red font=48 new");
   run("Select None");
   wait(2000);
   run("Hide Overlay");
   wait(2000);
   makeText("Goodbye", 50, 50);
   run("Add Selection...", "stroke=green font=48 new");
   run("Select None");

Another example is at

    http://rsbweb.nih.gov/ij/macros/examples/BlinkingText.txt

-wayne