render_image_block() {
	dir=$1
	src=$2
	alt=$3
	caption=$4
	open_attr=$(details_open_attr "$5")
	title=$6
	note=$7
	footer=$8
	header=$9

	[ -n "$title" ] || title=$src
	if ! safe_file_path "$dir" "$src"; then
		render_missing_image "Unsafe image source path: $src" "$title" "$note" "$header"
		return
	fi

	image_file=$dir/$src
	image_href=articles/${dir##*/}/$src
	alt_html=$(html_escape_attr "$alt")
	caption_html=$(html_escape_attr "$caption")

	if [ ! -f "$image_file" ]; then
		render_missing_image "Missing image source: $src" "$title" "$note" "$header"
		return
	fi

	if show_header "$header"; then
		want_header=1
		next_block_id
		if show_footer "$footer"; then
			want_footer=1
		else
			want_footer=0
		fi
	else
		want_header=0
		if show_explicit_footer "$footer"; then
			want_footer=1
		else
			want_footer=0
		fi
	fi
	if [ "$want_footer" = 1 ]; then
		size=$(format_size "$image_file")
	fi
	if [ "$want_header" = 1 ]; then
		printf '<details class="media-details"%s>\n' "$open_attr"
		if [ "$want_footer" = 1 ]; then
			render_block_summary "$title" "$note" "$image_href" "$block_id" "$block_id-footer"
		else
			render_block_summary "$title" "$note" "$image_href" "$block_id" ''
		fi
		block_class=image-block
	elif [ "$want_footer" = 1 ]; then
		printf '<div class="block-standalone">\n'
		block_class=image-block
	else
		block_class='image-block image-block-standalone'
	fi
	printf '  <figure class="%s">\n' "$block_class"
	printf '    <img src="%s" alt="%s" loading="lazy" decoding="async">\n' "$image_href" "$alt_html"
	if [ -n "$caption" ]; then
		printf '    <figcaption>%s</figcaption>\n' "$caption_html"
	fi
	printf '  </figure>\n'
	if [ "$want_footer" = 1 ]; then
		if [ "$want_header" = 1 ]; then
			render_block_footer "$title" "$size" "$image_href" "$block_id" "$block_id-footer"
		else
			render_block_footer "$title" "$size" "$image_href" '' ''
		fi
	fi
	if [ "$want_header" = 1 ]; then
		printf '</details>\n'
	elif [ "$want_footer" = 1 ]; then
		printf '</div>\n'
	fi
}