#!/bin/bash
# $Id: scan2web,v 1.8 2009/06/09 07:18:33 ajr Exp $
#
# Generate web-ready files from scanned originals

OEXT='web'	# name to append to file
SIZE=600	# final image size (default)
QUALITY=80	# final image JPEG quality
GAMMA='1.0'	# final image gamma adjustment
LEVEL='3%'	# levels adjustment
MASKOPACITY=30	# opacity of contrast mask
MASKBLUR=15	# amount of blur applied to mask
FILTER='sinc'	# filter type for resize
#TONE='brown4'	# toning colour
TONE='saddlebrown'	# toning colour
TONEAMOUNT='8%'	# toning amount

usage()
{
	echo "Usage: ${0##*/} [-c] [-g gamma] [-l level] [-m] [-o ext] [-r size] <file> [file ...]"
	echo "	-c = local contrast enhancement (unsharp mask)"
	echo "	-g = adjust gamma (default: $GAMMA)"
	echo "	-l = auto levels percentage (default: $LEVEL)"
	echo "	-m = apply contrast mask"
	echo "	-o = output file extension/type"
	echo "	-r = output size (longest side)"
}

while getopts cg:hl:mo:r: a; do
	case "$a" in
	c)	CLARITY=1
		;;
	g)	GAMMA="${OPTARG}%"
		;;
	h)	usage
		exit 0
		;;
	l)	LEVEL="${OPTARG}%"
		;;
	m)	MASK=1
		;;
	o)	OEXT="$OPTARG"
		;;
	r)	SIZE=$OPTARG
		;;
	*)	usage
		exit 1
		;;
	esac
done
shift $((OPTIND - 1))

if [ $SIZE -le 1500 ]; then
	TSIZE=$((SIZE * 3))	# work on large image for small target image
else
	TSIZE=$SIZE
fi

if [ -n "$CLARITY" ]; then
	CLARITYPARAM="-unsharp 50x7+0.4+0"
fi
for f in $@; do
	basename="${f%.*}"
	file="$f"

	if [ -n "$MASK" ]; then
		# create contrast mask
		convert "$f" -colorspace GRAY -negate -gaussian $MASKBLUR "${basename}-inv.$$.tif"
		#composite -dissolve $MASKOPACITY -compose overlay \
		composite -compose overlay -dissolve $MASKOPACITY \
		  "${basename}-inv.$$.tif" "$f" "${basename}-mask.$$.tif"
		if [ -s "${basename}-mask.$$.tif" ]; then
			file="${basename}-mask.$$.tif"
		else
			echo "${0##*/}: masking failed for $f, not done"
		fi
	fi
	convert -size ${TSIZE}x${TSIZE} "$file" \
	  -normalize -level $LEVEL -gamma $GAMMA $CLARITYPARAM \
	  -fuzz 5 -trim -unsharp 0x1+1 \
	  -filter ${FILTER} -resize ${SIZE}x${SIZE}\> \
	  -unsharp 0x1+0.4+0.01 -quality $QUALITY +profile icm \
	  -fill ${TONE} -colorize $TONEAMOUNT \
	  "${basename}-${OEXT}.jpg"
#	  -enhance -despeckle \
	if [ -n "$MASK" ]; then
		rm -f "${basename}-inv.$$.tif" "${basename}-mask.$$.tif"
	fi
done