Preparing a set of counters
Adding a border to the image
convert -bordercolor black -border 2 image_sin.png image_con.png
Turn the counter and adding a 5 pixel blue band
convert -rotate 180 -gravity north -background blue -splice 0x5 contadorA.png contadorA_r.png
Mounting the 2 images as a single one
montage -tile x2 -geometry ...