Running: for i in *.png ; do convert -liquid-rescale 'x40' $i png8:`basename $i .png`.small.png ; done does NOT preserve alpha channel
for i in *.png ; do convert -resize 'x40' $i png8:`basename $i .png`.small.png ; done does preserve alpha channel
Running:
for i in *.png ; do convert -liquid-rescale 'x40' $i png8:`basename $i .png`.small.png ; done
does NOT preserve alpha channel
for i in *.png ; do convert -resize 'x40' $i png8:`basename $i .png`.small.png ; done
does preserve alpha channel