Using Imagemagick, add watermark outside the image eg. using padding, in bulk? - imagemagick

Question

I am trying to add a watermark outside the image, creating firstly a padding place.
a) How can I do that? My imagemagick command have problem. Do not
cover all my image files eg. "DSC_5568 - DSC_5588_fused.jpg" did not add padding.
b) I can combine the two separate commands?
c) I want to do that in bulk
My imagemagick commands:
for pic in DSC*.*; do convert -background black -extent 0%x0%+0+100 $pic ${pic//.*}-padded.jpg; done
for pic in DSC*padded.*; do composite -dissolve 100% -gravity SouthEast watermark.png $pic ${pic//.*}-marked.jpg; done
example filenames:
"DSC_5568.JPG, DSC_5568 - DSC_5588_fused.jpg.... etc."

Answer 1

You really should provide sample input and expected output images, but I think you want this:
convert INPUT.JPG -background black -extent 0%x0%+0+100 -gravity southeast watermark.png -compose dissolve -composite RESULT.JPG
You may need to add this -define:
... watermark.png -define compose:args=100 -compose dissolve -composite ...
If that works, I would make a COPY of all your files in a spare directory and do the whole lot in parallel with GNU Parallel:
parallel 'convert {} -background black -extent 0%x0%+0+100 -gravity southeast watermark.png -compose dissolve -composite {.}-marked.jpg' ::: *.jpg
Or, if you prefer a simple bash for loop:
for f in DSC* ; do
convert "$f" -background black -extent 0%x0%+0+100 -gravity southeast watermark.png -compose dissolve -composite "${f//.*}-marked.jpg"
done

Answer 2

I found out how to process all my image files, using "" on the specified filenames.
for pic in DSC*.*; do convert -background black -extent 0%x0%+0+100 "$pic" "${pic//.*}-padded.jpg"; done
for pic in DSC*-padded.*; do composite -dissolve 100% -gravity SouthEast watermark.png "$pic" "${pic//.*}-marked.jpg"; done