Create Image drawable for all resolutions

converter.sh

if [ $# -eq 0 ]; then
	echo "No arguments supplied"
else if [ -f "$1" ]; then
	echo " Creating different dimensions (dips) of "$1" ..."
	mkdir -p drawable-xxhdpi
	mkdir -p drawable-xhdpi
	mkdir -p drawable-hdpi
	mkdir -p drawable-mdpi

	if [ $1 = "ic_launcher.png" ]; then
	    	echo "  App icon detected"
		convert ic_launcher.png -resize 144x144 drawable-xxhdpi/ic_launcher.png
		convert ic_launcher.png -resize 96x96 drawable-xhdpi/ic_launcher.png
		convert ic_launcher.png -resize 72x72 drawable-hdpi/ic_launcher.png
		convert ic_launcher.png -resize 48x48 drawable-mdpi/ic_launcher.png
		rm -i ic_launcher.png
	else
		convert $1 -resize 67% drawable-xhdpi/$1
		convert $1 -resize 50% drawable-hdpi/$1
		convert $1 -resize 33% drawable-mdpi/$1
		mv $1 drawable-xxhdpi/$1
	fi
	echo " Done"
else
	echo "$1 not found."
fi
fi

@matkoniecz Thanks for the suggestion.
https://github.com/Kishanjvaghela/drawable-converter
Please check it. Let me know its working or not for you.

Thanks for sharing this. It works great.
I've forked this gist and added xxxhdpi drawable generation. Also, added better documentation.
Here's my fork: https://gist.github.com/Abdallah-Abdelazim/af99647e1f9542fd4b4fa770c508c335