Handwriting to SVG: potrace and image magick

#!/bin/bash
set -eux

INPUT="$1"
OUTPUT="$2"

WORKDIR="$(mktemp -d)"
convert \
    -format bmp -colorspace gray -normalize \
    -threshold 90% "$INPUT" "$WORKDIR/bitmap.bmp"

potrace -b svg -r 300 -t 5 -o "$OUTPUT" "$WORKDIR/bitmap.bmp"