Use imagemagick to resize an image using a percentage:

mogrify -resize 21% *.jpg

resizes all jpegs in a directory
*WARNING* replaces original files

This next converts all the Gifs in a directory to jpegs:

mogrify -format jpg *.gif

convert -size 62×62 xc:white -font Candara-bold -pointsize 21 -fill black -annotate +15+38 “ant” ant.png

adjust the last two numbers to position the word in the space.