Linux - Shrink image size

# Loseless
# Shrink *.png with brute option(try all algo and use the best)
#  Prefix with s.
\ls *.png | xargs -n1 -I{} pngcrush -brute {} s{}
 
# Lossy shrinking: Output filename with suffix.
\ls *.png | xargs -n1 -I{} pngquant -f {}