ffmpeg: Placing an overlay over multiple images
If all TIFFs have the same properties, and are named sequentially like image0001.tif, then you can use
ffmpeg -i image%04d.tif -i my.png -filter_complex &quot;[1][0]scale2ref[i][m];[m][i]overlay&quot; out%04d.tif

This will generate images with the overlay named as follows
out0001.tif
out0002.tif
...