#!/bin/bash -e

CONVERT=(convert)
if command -v gm > /dev/null; then
    CONVERT=(gm "${CONVERT[@]}")
fi

mkdir -p test test_1080p

"${CONVERT[@]}" -size 3840x2160 xc:black test/000.png

printf '%s\n' {001..127} | xargs -P0 -I'{}' cp test/000.png test/'{}'.png