#!/bin/bash
#
# Developed by Fred Weinhaus 3/5/2021 .......... revised 3/5/2021
#
# ------------------------------------------------------------------------------
# 
# Licensing:
# 
# Copyright © Fred Weinhaus
# 
# My scripts are available free of charge for non-commercial use, ONLY.
# 
# For use of my scripts in commercial (for-profit) environments or 
# non-free applications, please contact me (Fred Weinhaus) for 
# licensing arrangements. My email address is fmw at alink dot net.
# 
# If you: 1) redistribute, 2) incorporate any of these scripts into other 
# free applications or 3) reprogram them in another scripting language, 
# then you must contact me for permission, especially if the result might 
# be used in a commercial or for-profit environment.
# 
# My scripts are also subject, in a subordinate manner, to the ImageMagick 
# license, which can be found at: http://www.imagemagick.org/script/license.php
# 
# ------------------------------------------------------------------------------
# 
####
#
# USAGE: vividize [-a amount] infile outfile
# USAGE: vividize [-h|-help]
#
# OPTIONS:
#
# -a amount      amount of vividization; 0<=integer<=100; default=100 
#                (full vividization)
#
###
#
# NAME: VIVIDIZE
# 
# PURPOSE: To enhance the colors in an image.
# 
# DESCRIPTION: VIVIDIZE enhances the colors in an image, i.e. makes the colors 
# more vivid. Processing is done in LAB colorspace.
# 
# 
# OPTIONS: 
# 
#
# -a amount ... AMOUNT of vividization. Values are 0<=integer<=100. The 
# default=100 (full vividization).
#
# CAVEAT: No guarantee that this script will work on all platforms, 
# nor that trapping of inconsistent parameters is complete and 
# foolproof. Use At Your Own Risk. 
# 
######
#

# set default values
amount=100			# amount of vividization

# set directory for temporary files
dir="."    # suggestions are dir="." or dir="/tmp"

# set up functions to report Usage and Usage with Description
PROGNAME=`type $0 | awk '{print $3}'`  # search for executable on path
PROGDIR=`dirname $PROGNAME`            # extract directory of program
PROGNAME=`basename $PROGNAME`          # base name of program
usage1() 
	{
	echo >&2 ""
	echo >&2 "$PROGNAME:" "$@"
	sed >&2 -e '1,/^####/d;  /^###/g;  /^#/!q;  s/^#//;  s/^ //;  4,$p' "$PROGDIR/$PROGNAME"
	}
usage2() 
	{
	echo >&2 ""
	echo >&2 "$PROGNAME:" "$@"
	sed >&2 -e '1,/^####/d;  /^######/g;  /^#/!q;  s/^#*//;  s/^ //;  4,$p' "$PROGDIR/$PROGNAME"
	}


# function to report error messages
errMsg()
	{
	echo ""
	echo $1
	echo ""
	usage1
	exit 1
	}

# function to test for minus at start of value of second part of option 1 or 2
checkMinus()
	{
	test=`echo "$1" | grep -c '^-.*$'`   # returns 1 if match; 0 otherwise
    [ $test -eq 1 ] && errMsg "$errorMsg"
	}

# test for correct number of arguments and get values
if [ $# -eq 0 ]
	then
	# help information
   echo ""
   usage2
   exit 0
elif [ $# -gt 4 ]
	then
	errMsg "--- TOO MANY ARGUMENTS WERE PROVIDED ---"
else
	while [ $# -gt 0 ]
		do
			# get parameter values
			case "$1" in
		   -h|-help)    # help information
					   echo ""
					   usage2
					   exit 0
					   ;;
	 		    -a)    # get amount
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID AMOUNT SPECIFICATION ---"
					   checkMinus "$1"
					   amount=`expr "$1" : '\([0-9]*\)'`
					   [ "$amount" = "" ] && errMsg "--- AMOUNT=$amount MUST BE A NON-NEGATIVE INTEGER ---"
					   test=`echo "$amount > 100" | bc`
					   [ $test -eq 1 ] && errMsg "--- AMOUNT=$amount MUST BE AN INTEGER BETWEEN 0 AND 100 ---"
					   ;;
 				 -)    # STDIN, end of arguments
  				 	   break
  				 	   ;;
				-*)    # any other - argument
					   errMsg "--- UNKNOWN OPTION ---"
					   ;;					   
		     	 *)    # end of arguments
					   break
					   ;;
			esac
			shift   # next option
	done
	#
	# get infile and outfile
	infile="$1"
	outfile="$2"
fi


# test that infile provided
[ "$infile" = "" ] && errMsg "NO INPUT FILE SPECIFIED"

# test that outfile provided
[ "$outfile" = "" ] && errMsg "NO OUTPUT FILE SPECIFIED"

# setup temporary images and auto delete upon exit
# use mpc/cache to hold input image temporarily in memory
tmpA="$dir/vividize_$$.mpc"
tmpB="$dir/vividize_$$.cache"
trap "rm -f $tmpA $tmpB; exit 0" 0
trap "rm -f $tmpA $tmpB; exit 1" 1 2 3 15
#trap "rm -f $tmpA $tmpB; exit 1" ERR

# test if infile exists and compute dimensions
convert -quiet "$infile" +repage "$tmpA" || \
	errMsg "--- FILE $infile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAS ZERO SIZE ---"

# get AB channel limits (smallest change from zero)
loval=`convert $tmpA -colorspace LAB \
	-format "%[fx:100*min(min(min(minima.g,minima.b),1-maxima.g),1-maxima.b)]" info:`

hival=`convert xc: -format "%[fx:100-$loval]" info:`

# convert amount to fraction
amt1=`convert xc: -format "%[fx:$amount/100]" info:`
amt2=`convert xc: -format "%[fx:1-$amt1]" info:`

# process image and blend with input
convert $tmpA \
	\( +clone -colorspace LAB \
	-channel R -auto-level +channel \
	-channel GB -level $loval,$hival% +channel \) \
	+colorspace \
	-set option:compose:args "0, $amt1, $amt2, 0" \
	-compose mathematics -composite \
	"$outfile"

exit 0