#!/usr/bin/env sh
set -e # exit on failure
IFS=$(printf '\n\t') # smarter ifs

test "$RATIOW" || RATIOW=16
test "$RATIOH" || RATIOH=9
imageh=$(identify -format %h "$1")
des_ratio=$(printf '3 k %u %u / p' "$RATIOW" "$RATIOH" | dc)
des_width=$(printf '1 k %f %u * p' "$des_ratio" "$imageh" | dc | cut -d. -f1)

convert "$1" -blur 0x7 -resize "$des_width"x tmp1.ppm
convert "$1" -bordercolor black -border 10x0 tmp2.ppm
composite -gravity center tmp2.ppm tmp1.ppm tmp3.ppm
mogrify -gravity center -crop "x$imageh+0" tmp3.ppm
outfile="$(dirname "$1")/tran_$(basename "$1" | tuc -d. -f:-2).jxl"
cjxl -e 8 tmp3.ppm "$outfile"
rm tmp*.ppm