make_telegram_stickerpack.sh

#!/usr/bin/env bash
NC='\033[0m'
GREEN='\033[0;32m'
BLUE='\033[0;34m'

SOURCE_DIR=${1%/}
TARGET_DIR="${SOURCE_DIR}_scaled"
TARGET_512_DIR="${SOURCE_DIR}_512"

if [ -z "$SOURCE_DIR" ];
then
  echo "Usage: make_telegram_pack [SOURCE_DIR]"
  exit
fi

get_image_ratio() {
  width=$(magick identify -format %w $1)
  height=$(magick identify -format %h $1)
  if [ $width -ge $height ]; then
    echo 1
  else
    echo 0
  fi
}

# Scale original images to 4x
echo -e "${BLUE}Upscaling original images to 4x...${NC}"
rm -rfv $TARGET_DIR
mkdir -pv $TARGET_DIR
for file in $SOURCE_DIR/*.png; do
  source=$file
  target=$TARGET_DIR/$(basename $file)
  ./tool/realesrgan-ncnn-vulkan -v -s 4 -i $source -o $target -n realesrgan-x4plus
done

# scale images to telegram 512px
echo -e "${BLUE}Downscaling 4x images to Telegram 512px...${NC}"
rm -rfv $TARGET_512_DIR
mkdir -pv $TARGET_512_DIR
for file in $TARGET_DIR/*.png; do
  source=$file
  target=$TARGET_512_DIR/$(basename $file)
  r=$(get_image_ratio $file)
  if [ $r -gt "0" ]; then
    magick convert $source -verbose -resize 512x $target
  else
    magick convert $source -verbose -resize x512 $target
  fi
done

echo -e "${GREEN}ALL DONE! Sticker pack saved at ${TARGET_512_DIR} .${NC}"