#!/bin/bash
#
# Developed by Fred Weinhaus 3/24/2008 .......... revised 8/17/2015
#
# ------------------------------------------------------------------------------
# 
# 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: colorspectrum [-c columns] [-r rows] [-l] infile outfile
# USAGE: colorspectrum [-h or -help]
#
# OPTIONS:
#
# -c        columns      width of spectrum; determines the maximum 
#                        number of colors; 1<=columns<=255; default=255
# -r        rows         height of spectrum; rows>=1; default=50
# -l                     displays a list of colors to the terminal
#
###
#
# NAME: COLORSPECTRUM 
# 
# PURPOSE: To generate a spectrum-like image from the colors in an image. 
# 
# DESCRIPTION: PROFILE generates generate a spectrum-like image from the 
# colors in an image. It uses a color reduction algorithm to extract the  
# specified number of colors. Then it sorts the colors according to hue and 
# creates an image of the specified height and width. See 
# http://www.imagemagick.org/script/quantize.php for a description of the 
# color reduction algorithm.
# 
# 
# OPTIONS: 
# 
# -c columns ... COLUMNS is the width of the spectrum and also determines the 
# number of colors to try to generate. Allowed values are integers between 
# 1 and 255. Note that it is possible that the color reduction algorithm will  
# produce fewer, but never more colors than desired. If fewer colors are 
# generated, then they will show as black areas on the left side of the  
# spectrum. The default is 255.
# 
# -r rows ... ROWS is the height of the spectrum. Values are integers 
# greater than 0. The default is 100.
# 
# -l ... Indicates to print a list of colors to the terminal.
#
# 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
columns=255
rows=50
list="no"

# 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 7 ]
	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
					   ;;
				-c)    # get columns=number of colors
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID COLUMNS SPECIFICATION ---"
					   checkMinus "$1"
					   columns=`expr "$1" : '\([0-9]*\)'`
					   [ "$columns" = "" ] && errMsg "--- COLUMNS=$columns MUST BE A POSITIVE INTEGER ---"
					   columnstestA=`echo "$columns < 1" | bc`
					   columnstestB=`echo "$columns > 255" | bc`
					   [ $columnstestA -eq 1 -o $columnstestB -eq 1 ] && errMsg "--- COLUMNS=$columns MUST BE AN INTEGER BETWEEN 1 AND 255 ---"
					   ;;
				-r)    # get rows
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID ROWS SPECIFICATION ---"
					   checkMinus "$1"
					   rows=`expr "$1" : '\([0-9]*\)'`
					   [ "$rows" = "" ] && errMsg "--- ROWS=$rows MUST BE A POSITIVE INTEGER ---"
					   rowstestA=`echo "$rows < 1" | bc`
					   [ $rowstestA -eq 1 ] && errMsg "--- ROWS=$rows MUST BE AN INTEGER GREATER THAN 0 ---"
					   ;;
				-l)    # get label
					   list="on"
					   ;;
				 -)    # STDIN and 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"

tmpA="$dir/colorspectrum_$$.mpc"
tmpB="$dir/colorspectrum_$$.cache"
tmp0="$dir/colorspectrum_0_$$.miff"
tmp1="$dir/colorspectrum_1_$$.miff"
tmp2="$dir/colorspectrum_2_$$.miff"
tmp3="$dir/colorspectrum_3_$$.miff"
trap "rm -f $tmpA $tmpB $tmp0 $tmp1 $tmp2 $tmp3;" 0
trap "rm -f $tmpA $tmpB $tmp0 $tmp1 $tmp2 $tmp3; exit 1" 1 2 3 15
trap "rm -f $tmpA $tmpB $tmp0 $tmp1 $tmp2 $tmp3; exit 1" ERR

if convert -quiet "$infile" +repage "$tmpA"
	then
	: 'do nothing'
	else
		errMsg "--- FILE $infile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAS ZERO SIZE ---"
fi

# test for minimum IM version
im_version=`convert -list configure | \
	sed '/^LIB_VERSION_NUMBER */!d; s//,/;  s/,/,0/g;  s/,0*\([0-9][0-9]\)/\1/g' | head -n 1`

# get colorspace and type
# colorspace swapped at IM 6.7.5.5, but not properly fixed until 6.7.6.6
# before swap verbose info reported colorspace=RGB after colorspace=sRGB
# not all formats report grayscale for colorspace (gif, tiff, jpg do not), but type will be grayscale
colorspace=`identify -ping -verbose $tmpA | sed -n 's/^.*Colorspace: \([^ ]*\).*$/\1/p'`
type=`identify -ping -verbose $tmpA | sed -n 's/^.*Type: \([^ ]*\).*$/\1/p'`
if [ "$colorspace" != "RGB" -a "$colorspace" != "sRGB" ]; then
	errMsg "--- FILE $infile MUST BE RGB, sRGB ---"
fi
if [ "$type" = "Grayscale" ]; then
	errMsg "--- HSL CONVERSION IS NOT ALLOWED WITH GRAYSCALE IMAGERY ---"
fi

# colorspace RGB and sRGB swapped between 6.7.5.5 and 6.7.6.7 
# though probably not resolved until the latter
# then -colorspace gray changed to linear between 6.7.6.7 and 6.7.8.2 
# then -separate converted to linear gray channels between 6.7.6.7 and 6.7.8.2,
# though probably not resolved until the latter
# so -colorspace HSL/HSB -separate and -colorspace gray became linear
# but we need to use -set colorspace RGB before using them at appropriate times
# so that results stay as in original script
# The following was determined from various version tests using colorspectrum.
# with IM 6.7.4.10, 6.7.6.10, 6.7.8.6
# Note: added $setcspace after generating PPM image and before converting to HSL
# Slight difference in color arrangement for IM before 6.7.6.7
if [ "$im_version" -lt "06070607" -o "$im_version" -gt "06070707" ]; then
	cspace="RGB"
else
	cspace="sRGB"
fi
if [ "$im_version" -lt "06070607" -o "$im_version" -gt "06070707" ]; then
	setcspace="-set colorspace RGB"
else
	setcspace=""
fi
# no need for setcspace for grayscale or channels after 6.8.5.4
if [ "$im_version" -gt "06080504" ]; then
	setcspace=""
	cspace="sRGB"
fi

# get quantum max value
qmax=`convert xc: -format "%[fx:QuantumRange]" info:`
qval=`convert xc: -format "%q" info:`

# get unique spectrum colors from rgb image as lines of text
data1=`convert $tmpA -alpha off -depth $qval +dither -colors $columns -unique-colors txt:-`
# test if % or empty
# keep only second line
# remove all chars but 0-9.%
# get third word (first/red graylevel value)
# remove every char but %
test1=`echo "$data1" | sed -n 2p | tr -cs "0-9.%" " " | cut -d\  -f3 | sed -n 's/[^%]*//p'`
#echo "test1=$test1;"
if [ "$test1" = "%" ]; then
	# newer txt format using % values
	# 1st sed command removes spaces
	# 2nd sed command strips everything but color values
	# 3rd sed command replaces commas with spaces
	# 4th sed removes %
	# 5th sed command prints all lines but first
	# when echo "$data" it prints each row
	# when echo $data it prints each line feed as a space so it is all one line.
	spectrum1=`echo "$data1" |\
		sed -n 's/ //g; s/^[0-9]*,[0-9]*[:][ ]*[(]\([.0-9%]*,[.0-9%]*,[.0-9%]*\)[)][#].*$/\1/; s/,/ /g; s/%//g; 2,$p'`
elif [ "$test1" = "" ]; then
	# older txt format using raw values
	# 1st sed command removes spaces
	# 2nd sed command strips everything but color values
	# 3rd sed command replaces commas with spaces
	# 4th sed command prints all lines but first
	# when echo "$data" it prints each row
	# when echo $data it prints each line feed as a space so it is all one line.
	spectrum1=`echo "$data1" |\
		sed -n 's/ //g; s/^[0-9]*,[0-9]*[:][ ]*[(]\([ 0-9]*,[ 0-9]*,[ 0-9]*\)[)][#].*$/\1/; s/,/ /g; 2,$p'`
else
	errMsg "---	INVALID TXT FORMAT ---"
fi

if [ "$test1" = "%" ]; then
spectrum1=`echo "$spectrum1" |\
	awk -v qmax="$qmax" ' { r=int($1*qmax/100+0.5); g=int($2*qmax/100+0.5); b=int($3*qmax/100+0.5); print r, g, b; } '`
fi
#echo "spectrum1=$spectrum1"

# use actual number of colors found
colorsArr=($spectrum1)
numcolors=${#colorsArr[*]}
columns=`convert xc: -format "%[fx:floor($numcolors/3)]" info:`
#echo "numcolors=$numcolors; columns=$columns;"

# convert rgb text spectrum to HSL single row image
# Use NetPBM (PPM plain color format implied intermediate image)
echo "P3 $columns 1 $qmax $spectrum1" | convert - $setcspace -colorspace HSL $tmp0


# convert HSL single row colors image back to text and sort according to hue
data2=`convert $tmp0 txt:-`
# test if % or empty
# keep only second line
# remove all chars but 0-9.%
# get third word (first/red graylevel value)
# remove every char but %
test2=`echo "$data2" | sed -n 2p | tr -cs "0-9.%" " " | cut -d\  -f5 | sed -n 's/[^%]*//p'`
#echo "test2=$test2;"
if [ "$test2" = "%" ]; then
	# newer txt format using % values
	# 1st sed command removes spaces
	# 2nd sed command strips everything but color values
	# 3rd sed command replaces commas with spaces
	# 4th sed removes %
	# 5th sed command prints all lines but first
	# when echo "$data" it prints each row
	# when echo $data it prints each line feed as a space so it is all one line.
	#
	# note: starting at IM 6.9.2.1 HSL is in format HSL(0-360,percent,percent)
	if [ "$im_version" -lt "06090201" ]; then
		spectrum2=`echo "$data2" |\
			sed -n 's/ //g; s/^[0-9]*,[0-9]*[:][ ]*[(]\([.0-9%]*,[.0-9%]*,[.0-9%]*\)[)][#].*$/\1/; s/,/ /g; s/%//g; 2,$p' |\
			sort -n -k 1,1`
	elif [ "$im_version" -ge "06090201" ]; then
		spectrum2=`echo "$data2" |\
			sed -n 's/ //g; s/^[0-9]*,[0-9]*[:][ ]*[(]\([0-9]*,[.0-9%]*,[.0-9%]*\)[)][#].*$/\1/; s/,/ /g; s/%//g; 2,$p' |\
			sort -n -k 1,1`
	fi
elif [ "$test2" = "" ]; then
	# older txt format using raw values
	# 1st sed command removes spaces
	# 2nd sed command strips everything but color values
	# 3rd sed command replaces commas with spaces
	# 4th sed command prints all lines but first
	# when echo "$data" it prints each row
	# when echo $data it prints each line feed as a space so it is all one line.
	spectrum2=`echo "$data2" |\
		sed -n 's/ //g; s/^[0-9]*,[0-9]*[:][ ]*[(]\([ 0-9]*,[ 0-9]*,[ 0-9]*\)[)][#].*$/\1/; s/,/ /g; 2,$p' |\
		sort -n -k 1,1`
else
	errMsg "---	INVALID TXT FORMAT ---"
fi

if [ "$test2" = "%" ]; then
	if [ "$im_version" -lt "06090201" ]; then
		spectrum2=`echo "$spectrum2" |\
			awk -v qmax="$qmax" ' { r=int($1*qmax/100+0.5); g=int($2*qmax/100+0.5); b=int($3*qmax/100+0.5); print r, g, b; } '`
	elif [ "$im_version" -ge "06090201" ]; then
		spectrum2=`echo "$spectrum2" |\
			awk -v qmax="$qmax" ' { r=int($1*qmax/360+0.5); g=int($2*qmax/100+0.5); b=int($3*qmax/100+0.5); print r, g, b; } '`
	fi
fi
#echo "spectrum2=$spectrum2"


# convert sorted HSL text colors to single row HSL image
echo "P3 $columns 1 $qmax $spectrum2" | convert - $tmp0


# convert HSL colors single row image to RGB single row spectrum image
convert $tmp0 $setcspace -channel Red -separate $tmp1
convert $tmp0 $setcspace -channel Green -separate $tmp2
convert $tmp0 $setcspace -channel Blue -separate $tmp3
convert $tmp1 -colorspace HSL \
	$tmp1 -compose CopyRed -composite \
	$tmp2 -compose CopyGreen -composite \
	$tmp3 -compose CopyBlue -composite \
	-colorspace $cspace $tmp0


if [ "$list" = "on" ]
	then

	data3=`convert $tmp0 txt:-`
	# test if % or empty
	# keep only second line
	# remove all chars but 0-9.%
	# get third word (first/red graylevel value)
	# remove every char but %
	test3=`echo "$data3" | sed -n 2p | tr -cs "0-9.%" " " | cut -d\  -f3 | sed -n 's/[^%]*//p'`
	#echo "test3=$test3;"
	if [ "$test3" = "%" ]; then
		# newer txt format using % values
		# 1st sed command removes spaces
		# 2nd sed command strips everything but color values
		# 3rd sed command replaces commas with spaces
		# 4th sed removes %
		# 5th sed command prints all lines but first
		# when echo "$data" it prints each row
		# when echo $data it prints each line feed as a space so it is all one line.
		spectrum3=`echo "$data3" |\
			sed -n 's/ //g; s/^[0-9]*,[0-9]*[:][ ]*[(]\([.0-9%]*,[.0-9%]*,[.0-9%]*\)[)][#].*$/\1/; s/,/ /g; 2,$p'`
	elif [ "$test3" = "" ]; then
		# older txt format using raw values
		# 1st sed command removes spaces
		# 2nd sed command strips everything but color values
		# 3rd sed command replaces commas with spaces
		# 4th sed command prints all lines but first
		# when echo "$data" it prints each row
		# when echo $data it prints each line feed as a space so it is all one line.
		spectrum3=`echo "$data3" |\
			sed -n 's/ //g; s/^[0-9]*,[0-9]*[:][ ]*[(]\([ 0-9]*,[ 0-9]*,[ 0-9]*\)[)][#].*$/\1/; s/,/ /g; 2,$p'`
	else
		errMsg "---	INVALID TXT FORMAT ---"
	fi
	
	echo ""
	echo "List Of Colors - RGB Values 0 to Quantum Max or Percent"
	echo ""
	echo "$spectrum3"
	echo ""
fi

# scale to desired height
convert $tmp0 -scale ${columns}x${rows}! "$outfile"

exit 0