image2slack-emoji.sh

#!/bin/bash

if [ $# -ne 2 ]; then
  echo "usege: $0 input_image_path output_image_path"
  exit 1
fi

INPUT_PATH=$1
OUTPUT_PATH=$2

convert ${INPUT_PATH} \
  -alpha set \
  -background none \
  -channel RGBA \
  -fill '#00000000' \
  -fuzz 5% \
  -draw 'matte 1,1 floodfill' \
  -resize '128x128>' \
  -trim \
  ${OUTPUT_PATH}

text2slack-emoji.sh

#!/bin/bash

if [ $# -ne 2 ]; then
  echo "usege: $0 convert_text output_image_path"
  exit 1
fi

INPUT_TEXT=$1
OUTPUT_PATH=$2

convert \
 -font ipag.ttc \
 -pointsize 128 \
 caption:"${INPUT_TEXT}" \
 -trim \
 -transparent white \
 -resize '128x128>' \
 ${OUTPUT_PATH}