nativefier/icon-scripts/convertToIco

#!/usr/bin/env bash

# USAGE

# ./convertToIco <input png or ico> <outfilename>.ico
# Example
# ./convertToPng ~/sample.png ~/converted.ico

set -e

CONVERT=

type gm &>/dev/null && gm version | grep GraphicsMagick &>/dev/null && CONVERT="gm convert"
type convert &>/dev/null && CONVERT="convert"

[[ -z "$CONVERT" ]] && { echo >&2 "Cannot find required ImageMagick Convert or GraphicsMagick executable"; exit 1; }

SOURCE=$1
DEST=$2

if [ -z "${SOURCE}" ]; then
	echo "No source image specified"
	exit 1
fi

if [ -z "${DEST}" ]; then
	echo "No destination specified"
	exit 1
fi

NAME=$(basename "${SOURCE}")
EXT="${NAME##*.}"

if [ "${EXT}" == "ico" ]; then
    cp "${SOURCE}" "${DEST}"
    exit 0
fi

$CONVERT "${SOURCE}" -resize 256x256 "${DEST}"