Convert drawable resources from xhdpi to hdpi, mdpi and ldpi

scale_resources.sh

#!/bin/bash

# add desired categories
CATEGORIES=ldpi,mdpi,hdpi
# categories scale in % based on xhdpi
CATEGORIES_SCALE=37.5,50,75

IFS=',' read -a densities <<< "$CATEGORIES"
IFS=',' read -a scales <<< "$CATEGORIES_SCALE"

for index in "${!densities[@]}"
do
    
    echo processig ${densities[index]} resources...      
    if [ ! -d "res/drawable-${densities[index]}" ] 
    then 
      mkdir res/drawable-${densities[index]}
    fi

    for i in `find res/drawable-xhdpi/ -name *.png`
    do
	convert $i -resize ${scales[index]}% res/drawable-${densities[index]}/${i##*/}
    done

done