Add a scale-bar to images via command line (with Ubuntu and eg ImageJ)

Question

at the moment I am using ImageJ (with my Ubuntu 14.04) to manually add Scale-Bars to Images (semi-manually to be precise as I'm using „File → Import → Image Sequence…“). I have recorded a macro (in ImageJ via: Plugins → Macros → Record...) that looks as follows:

run("Blobs (25K)");
run("Set Scale...", "distance=500.5 known=200 pixel=1 unit=µm");
  <<warning: the options string contains one or more non-ascii characters>>
run("Scale Bar...", "width=200 height=8 font=28 color=Black background=None location=[Lower Right] bold overlay");

How would the complete command look like when I want to add a scale bar to hundred images (eg /home/$USER/test/*.tif)

Actually I don't necessarily have to use ImageJ. If that was also easily possible with ImageMagick for example that would be totally fine as well.

Answer 1

It's hard to tell what your images look like or your scale bar. Let's suppose your image looks like this:

and that you can create a scale-bar on a transparent background using a drawing package like this:

You can then composite that scale-bar onto your chart like this with ImageMagick:

convert -gravity southeast chart.tif scale.png -composite result.png

If you want to move it up 30px and across 40px, do this:

convert -gravity southeast chart.tif scale.png -geometry +40+30 -composite result.png

Obviously change the -gravity to southwest if you want it bottom-left.

If you have a load of images to do - FIRST MAKE A COPY OR BACKUP, then try this

#!/bin/bash
mkdir annotated
for f in *.tif; do
   convert -gravity southeast "$f" scale.png -geometry +40+30 -composite  annotated/"$f"
done