To generate 100 images, containing numbers 0 to 100:

for f in `seq 0 100` ; do convert -size 25x25 xc:transparent -font /usr/share/fonts/truetype/ttf-dejavu/DejaVuSansMono-Bold.ttf \ -fill $COLOR -pointsize 19 -draw "text 1,20 '$f'" res/drawable/notify\_$f.png done