How to display length on the image

Hi there,

I know how to measure the length in the ImageJ. However, if I want to display the length on the image, how could I do that? I found some answers by searching but none of those methods worked.

Thank you,

Rick

A simple way would be to use the scale bar of ImageJ. Create a line selection from 0 to length and then invoke the scale bar action: Analyze->Tools->Scale bar

Here a short macro example to visualize the width of an example image:

run("Blobs (25K)");
makeLine(0, 59, 256, 60);
run("Scale Bar...", "width=256 height=4 font=14 color=White background=None location=[At Selection] bold");

Result:

See also:

https://imagej.nih.gov/ij/docs/guide/146-30.html#toc-Subsection-30.14