#!/bin/bash # # Developed by Fred Weinhaus 8/27/2007 .......... revised 12/18/2022 # Contrast limiting technique by Alan Gibson (user snibgo) ... 7/3/2013 # # ------------------------------------------------------------------------------ # # 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: redist [-s shape] [-m colormodel] [-c channel] [-g graytype] # [-f factor] [-G] [-L] [mean[,lo[,hi]]] infile outfile # USAGE: redist [-h or -help] # # -h or -help get help # -s shape redistribution shape; choices are: Gaussian or Uniform; # default is Gaussian # -m colormodel processing (color) model; default=RGB # -c channel channel number to process; channel=0,1,2; # default -> see below # -g graytype type of grayscale image to use when colormodel=RGB; # choices are: gray, rec601, rec709, lightness, brightness, # ave, luminance, demodhsl, demodhcl; default=gray # -f factor factor the contrast gain limiting factor; smaller values # will limit contrast gain more; values above about 3 will # produce no contrast limit; float>=0; # default is no threshold # -G display the grayscale histogram (graph) with # distribution function overlay # -L save the lookup table image; if saved, it will # be named redist_lut.png # mean desired mean for Gaussian distribution; # mean in range 0 to 100; default=60 # lo desired 1 sigma roll-off point of distribution on the # low side of the Gaussian peak; lo > 0; default=60 # hi desired 1 sigma roll-off point of distribution on the # high side of the Gaussian peak; hi > 0; default=60 # ### # # NAME: REDIST # # PURPOSE: To modify an image so that its (grayscale) histogram has either # a Gaussian (sometimes called normal or bell-shaped) distribution or # a Uniform (constant height) distribution. The latter is equivalent to # histogram equalization. # # DESCRIPTION: REDIST is designed to apply an intensity mapping # transformation to an image such that the resulting image's grayscale # histogram has a specified distribution shape (Gaussian or Uniform). For # colormodel not equal to RGB, it first converts the image to that # color space via the colormodel parameter and processes the intensity-like # channel. For colormodel=RGB, it converts the image to an appropriate # intensity-like channel as specified by graytype. Either way it computes the # intensity-like channel's cumulative histogram. The script then generates the # integral of the specified distribution scaled to the last value in the # cumulative histogram. For each value in the image's cumulative histogram, # it finds the closest value in the integral and then looks to see what its # graylevel value is. It uses those graylevel values as the y-value in a # mapping transformation whose x-values range from 0-255. This mapping # transformation is expressed as a 1-D image and used with the IM function # -fx or -clut to transform the input image. For colormodel not RGB, it process # only the intensity-like channel and then recombines the channels and converts # back to RGB. For colormodel RGB, it applies the transformation to each # channel of the RGB image. If a graph is desired, it is normally just viewed. # However, a default parameter in the program can be set to allow it to be # saved as outfilename_graph.gif. To end the script, close/quit the graph image. # # # ARGUMENTS: # # -s SHAPE defines the desired distribution shape, which can be either # Gaussian (also known as normal or bell-shaped) or Uniform (constant # height). The default is Gaussian if -s shape is not specified. # # -m COLORMODEL defines the color model to use for the processing of an # RGB color image into a grayscale image in order to compute the required # cumulative histogram. If a colormodel other than RGB or GLOBAL is # specified, then the image is first transformed into that color space and # an intensity-like channel will then be used to compute the cumulative # histogram. If RGB is selected, the RGB image is converted to an appropriate # grayscale according to the graytype. This grayscale image is then used to # generate the cumulative histogram. If GLOBAL is selected, then the combined # cumulative histogram from all the channels is computed. The default value is # RGB when colormodel is not provided. Note that results vary between the # different color models. # # -c CHANNEL defines which channel to use for the histogram processing. # Values for channel may be 0, 1 or 2, which correspond to those generated # by the conversion to that color space. For RGB, this is R=0, G=1, B=2. # For HSL, this is H=0, S=1, L=2. The same goes for the other color spaces. # This will override the default value which is set for most colorspaces # to the most intensity-like channel. For HSL and HSB, this is channel 2. # For all others except RGB and GLOBAL, this is channel 0. For GLOBAL, # all channels will be combined to compute the histogram. # # -g GRAYTYPE defines the type of grayscale image to use when colormodel=RGB. # The choices are: gray (same as rec609luma; YUV, YIQ, YCbCr channel 1; # HCL channel 2), rec709 (which is rec709luma), lightness (from HSL channel 2), # brightness (from HSB channel 2), ave (from OHTA channel 1), luminance (from LAB # channel 0), demodhsl (demodulate in HSL) and demodhcl (demodulate in HCL). The # default=gray. Note that gray is the same as rec601luma prior to IM 6.8.5.5 # and is the same as rec709luma for IM 6.8.5.5 forward. # # -f factor ... FACTOR is the contrast gain limiting factor. Smaller values # will limit contrast gain more; values above about 3 will produce no contrast # limit. Values are floats>=0. The default is no contrast gain limitation. # The factor is used to combine the histogram count mean and standard deviation # to compute a maximum threshold for the histogram counts in order to limit the # contrast. The threshold=countmean+factor*countstd. # # -L ... Save the lookup table image. If saved, it will be named # redist_lut.png # # -G ... Display the grayscale histogram (graph) with the distribution # function overlay # # MEAN is the desired center point for the peak in the Gaussian # distribution. It is an integer in the range of 0 to 100 (graylevel %). # Its default value is 60. # # LO is the desired 1 sigma roll-off point on the low side of the # distribution, expressed as pixels from the peak. This is where # the Gaussian shape has dropped to 61% of its maximum value. The # range between the peak and this point, will contain 34% of all the # pixels in the image. It is an integer which is greater than zero. # Its default is 60. # # HI is the desired 1 sigma roll-off point on the high side of the # distribution, expressed as pixels from the peak. This is where # the Gaussian shape has dropped to 61% of its maximum value. The # range between the peak and this point, will contain 34% of all the # pixels in the image. It is an integer which is greater than zero. # Its default is 60. If LO is provided, but not HI, then HI will be # set equal to LO. # # NOTE: If you want different default values for mean, lo and hi, # you may set them within the script, just below # # REQUIRES: NetPBM PGM format intermediate image. See # http://netpbm.sourceforge.net/ # # NOTE: Thanks to Anthony Thyssen for the suggested changes from shell # calculations for the histograms to the use of AWK. This has produced # a 10x performance speed up. # # 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 value dmean=60 dlo=60 dhi=60 maxval=65535 shape="gaussian" colormodel="RGB" channel="" graytype="GRAY" factor="" display_graph="no" graph="view" # 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 function checkMinus { test=`echo $val | grep -c '^-.*$'` # returns 1 if match; 0 otherwise if [ $test -eq 1 ] then errMsg "$errorMsg" fi } # function to get cumulative histogram cumHistogram() { img="$1" histArr=(`convert $img -colorspace gray -depth 8 -format "%c" histogram:info:- \ | sed -n 's/[ ]*\([0-9]*\).*gray[(]\([0-9]*\).*$/\1 \2/p' |\ awk ' # AWK to generate a zero filled histogram { bin[int($2)] += $1; } END { for (i=0;i<256;i++) {hist = bin[i]+0; print hist; } } '`) # echo ${histArr[*]} # echo ${#histArr[*]} if [ "$factor" = "" ]; then ccountArr=(`echo ${histArr[*]} |\ awk '# AWK to generate a cumulative histogram { split($0,count," ") } END { for (i=0;i<256;i++) { cum += count[i]; print cum } } '`) totpix=${ccountArr[255]} # echo ${ccountArr[*]} # echo ${#ccountArr[*]} else mean_std=`echo ${histArr[*]} | tr " " "\n" |\ awk ' # AWK to generate count mean and std of histogram { sum += $1; sumsq += $1*$1; } END { mean=sum/256; std=sqrt(sumsq/256 - mean*mean); print mean, std } '` cmean=`echo $mean_std | cut -d\ -f1` cstd=`echo $mean_std | cut -d\ -f2` # echo "cmean=$cmean; cstd=$cstd;" # compute count_threshold for clipping the histogram count_threshold=`convert xc: -format "%[fx:$cmean+$factor*$cstd]" info:` ccountArr=(`echo ${histArr[*]} |\ awk -v thresh="$count_threshold" '# AWK to generate a cumulative histogram { split($0,count," ") } END { for (i=0;i<256;i++) { cum += (count[i]>thresh)?thresh:count[i]; print cum } } '`) totpix=${ccountArr[255]} # echo ${ccountArr[*]} # echo ${#ccountArr[*]} fi } # function to generate gaussian array in two parts: 0 to mean and mean to 255 gaussian() { mean=`echo "scale=0; 256 * $mean / 100" | bc` expo=`convert xc: -format "%[fx:e]" info:` # create low part of gaussian distribution fact=`convert xc: -format "%[fx:1/(2*($lo)^2)]" info:` loArr=(`awk -v mean="$mean" -v fact="$fact" -v expo="$expo" -v maxval="$maxval" ' BEGIN { for (i=0;i<=mean;i++) print maxval*expo^(-((i-mean)^2)*fact); }'`) # echo ${loArr[*]} # echo ${#loArr[*]} # create high part of gaussian distribution mean1=`expr $mean + 1` fact=`convert xc: -format "%[fx:1/(2*($hi)^2)]" info:` hiArr=(`awk -v mean="$mean" -v fact="$fact" -v expo="$expo" -v maxval="$maxval" ' BEGIN { for (i=mean+1;i<256;i++) print maxval*expo^(-((i-mean)^2)*fact); }'`) # echo ${hiArr[*]} # echo ${#hiArr[*]} # combine low and high parts of gaussian distribution gausslist="${loArr[*]} ${hiArr[*]}" functionArr=($gausslist) # echo ${functionArr[*]} # echo ${#functionArr[*]} } integrateFunction() { # integrate function distribution intFunctionList=$(for ((i=0; i<256; i++)); do echo "$i ${functionArr[$i]}" done |\ awk -v totpix="$totpix" '# AWK to integrate a function { cum += $2; rcum[$1] = cum; } END { for (i=0;i<256;i++) print int(totpix*rcum[i]/cum); }') integralArr=($intFunctionList) # echo ${integralArr[*]} # echo ${#integralArr[*]} } # function to generate lut from matching the cumulative histogram with the function integral genLutArr() { # for each possible bin graylevel (0 to 255) of cc2 starting at 0 # get count from cumulate histogram cc2 at that bin, then # increment along bin graylevels of integrated function cc1 until that count exceeds that of cc2 # find the bin graylevel in cc1 and use that as the output value of the lut transformation # where the cc2 bin graylevel is the input value of the lut transformation # repeat for the next cc2 bin, but starting at graylevel where left off from previous. # as cumulative histograms never decrease, you don't have to start at graylevel 0 each time lutlist=$(for ((i=0; i<256; i++)); do echo "$i ${integralArr[$i]} ${ccountArr[$i]}" done |\ awk -v maxval="$maxval" '# AWK to generate transformation lut BEGIN { i=0; } { cc1[$1]=$2; cc2[$1]=$3; } END { for ( j=0;j<256;j++ ) { while ( i != 255 && cc1[i] <= cc2[j] ) { i++ } lut = maxval*i/255; print lut; } }') } # special function to generate lut for Uniform Distribution which is just the cumulative histogram normalized to max value genUniformLutArr() { # the uniform distribution has an integral which is f(x)=x # this means that the cumulative distribution of the image is its own lut and only needs to be scaled # get raw cumulative histogram fact=`convert xc: -format "%[fx:$maxval/$totpix]" info:` lutlist=$(for ((i=0; i<256; i++)); do echo "${ccountArr[$i]}" done |\ awk -v fact="$fact" '{ print int(fact*$1); }') } # test for correct number of arguments and get values if [ $# -eq 0 ] then # help information echo "" usage2 exit 0 elif [ $# -gt 15 ] then errMsg "--- TOO MANY ARGUMENTS WERE PROVIDED ---" else mean="" lo="" hi="" while [ $# -gt 0 ] do # get parameter values case "$1" in -h|-help) # help information echo "" usage2 exit 0 ;; -G) # display graph display_graph="yes" ;; -s) # distribution shape shift # to get the next parameter # test if parameter starts with minus sign shape=$1 if [ "$shape" != "Gaussian" -a "$shape" != "gaussian" -a "$shape" != "Uniform" -a "$shape" != "uniform" ] then errMsg "--- SHAPE=$shape IS NOT A VALID VALUE ---" fi errorMsg="--- INCORRECT SHAPE PARAMETER SPECIFICATION ---" val=$shape checkMinus ;; -m) # colorspace model shift # to get the next parameter # test if parameter starts with minus sign colormodel=$1 colormodel=`echo "$colormodel" | tr "[:lower:]" "[:upper:]"` errorMsg="--- INCORRECT MODEL PARAMETER SPECIFICATION ---" val=$colormodel checkMinus ;; -c) # channel number shift # to get the next parameter # test if parameter starts with minus sign channel=$1 if [ $channel -ne 0 -a $channel -ne 1 -a $channel -ne 2 ] then errMsg "--- CHANNEL=$channel IS NOT A VALID VALUE ---" fi errorMsg="--- INCORRECT CHANNEL PARAMETER SPECIFICATION ---" val=$channel checkMinus ;; -g) # get graytype shift # to get the next parameter # test if parameter starts with minus sign errorMsg="--- INVALID GRAYTYPE SPECIFICATION ---" checkMinus "$1" graytype="$1" graytype=`echo "$graytype" | tr "[:lower:]" "[:upper:]"` case "$graytype" in GRAY) ;; REC601) ;; REC709) ;; LIGHTNESS) ;; BRIGHTNESS) ;; AVE) ;; LUMINANCE) ;; DEMODHSL) ;; DEMODHCL) ;; *) errMsg "--- GRAYTYPE=$graytype IS NOT A VALID VALUE ---" ;; esac ;; -f) # get factor shift # to get the next parameter # test if parameter starts with minus sign errorMsg="--- INVALID FACTOR SPECIFICATION ---" checkMinus "$1" factor=`expr "$1" : '\([.0-9]*\)'` [ "$factor" = "" ] && errMsg "--- FACTOR=$factor MUST BE A NON-NEGATIVE FLOAT ---" ;; -L) # get savelut savelut="yes" ;; -) # STDIN, end of arguments break ;; -*) # any other - argument errMsg "--- UNKNOWN OPTION ---" ;; [0-9,]*[^a-zA-Z]) # Values supplied - need to test with and without trailing comma mean=`expr "$1" : '\([0-9]*\)[,].*'` if [ "$mean" = "" ] then mean=`expr "$1" : '\([0-9]*\)'` [ "$mean" != "" ] && lo=$dlo; hi=$dhi [ "$mean" = "" ] && mean=$dmean; lo=$dlo; hi=$dhi fi meantestA=`echo "$mean < 0" | bc` meantestB=`echo "$mean > 100" | bc` [ $meantestA -eq 1 -o $meantestB -eq 1 ] && errMsg "--- MEAN=$mean MUST BE GREATER THAN OR EQUAL 0 AND LESS THAN OR EQUAL 100 ---" # lo=`expr "$1" : '[0-9]*[,]\([0-9]*\)[,].*'` if [ "$lo" = "" ] then lo=`expr "$1" : '[0-9]*[,]\([0-9]*\)'` [ "$lo" != "" ] && hi=$lo [ "$lo" = "" ] && lo=$dlo; hi=$dlo fi lotest=`echo "$lo <= 0" | bc` [ $lotest -eq 1 ] && errMsg "--- LO=$lo MUST BE GREATER THAN 0 ---" # hi=`expr "$1" : '[0-9]*[,][0-9]*[,]\([0-9]*\)'` [ "$hi" = "" -a $lo -ne $dlo ] && hi=$lo [ "$hi" = "" -a $lo -eq $dlo ] && hi=$dhi hitest=`echo "$hi <= 0" | bc` [ $hitest -eq 1 ] && errMsg "--- HI=$hi MUST BE GREATER THAN 0 ---" ;; .*,.*) # Bogus Values supplied errMsg "--- MEAN, LO AND/OR HI VALUES ARE NOT VALID ---" ;; *) # end of arguments break ;; esac shift # next option done # # get infile and outfile infile="$1" outfile="$2" # # if nothing supplied for mean,lo,hi then set to defaults [ "$mean" = "" ] && mean=$dmean [ "$lo" = "" ] && lo=$dlo [ "$hi" = "" ] && hi=$dhi fi # setup temporary images and auto delete upon exit # use mpc/cache to hold input image temporarily in memory #tmpA="$dir/redist_$$.mpc" #tmpB="$dir/redist_$$.cache" # use miff instead as mpc/cache produces too many values/counts for the same bin in the IM histogram that need to be combined tmpA="$dir/redist_$$.miff" tmp0="$dir/redist_0_$$.miff" tmp1="$dir/redist_1_$$.miff" tmp2="$dir/redist_2_$$.miff" tmpP="$dir/redist_proc_$$.miff" tmp3="$dir/redist_3_$$.miff" # get outfile name before suffix outname=`echo "$outfile" | sed -n 's/^\([^.]*\)[.][^.]*$/\1/ p'` hg="_histgraph" tmp4="$dir/$outname$hg.gif" if [ "$graph" = "view" ] then trap "rm -f $tmpA $tmpB $tmp0 $tmp1 $tmp2 $tmpP $tmp3 $tmp4;" 0 trap "rm -f $tmpA $tmpB $tmp0 $tmp1 $tmp2 $tmpP $tmp3 $tmp4; exit 1" 1 2 3 15 trap "rm -f $tmpA $tmpB $tmp0 $tmp1 $tmp2 $tmpP $tmp3 $tmp4; exit 1" ERR elif [ "$graph" = "save" ] then trap "rm -f $tmpA $tmpB $tmp0 $tmp1 $tmp2 $tmpP $tmp3;" 0 trap "rm -f $tmpA $tmpB $tmp0 $tmp1 $tmp2 $tmpP $tmp3; exit 1" 1 2 3 15 trap "rm -f $tmpA $tmpB $tmp0 $tmp1 $tmp2 $tmpP $tmp3; exit 1" ERR else errMsg "--- NOT A VALID GRAPH DISPLAY OPTION ---" fi # test that infile provided [ "$infile" = "" ] && errMsg "NO INPUT FILE SPECIFIED" # test that outfile provided [ "$outfile" = "" ] && errMsg "NO OUTPUT FILE SPECIFIED" # get 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` if [ "$im_version" -ge "07000000" ]; then identifying="magick identify" else identifying="identify" fi # colorspace RGB and sRGB swapped between 6.7.5.5 and 6.7.6.7 # though probably not resolved until the latter # then -colorspace gray changed to linear between 6.7.6.7 and 6.7.8.2 # then -separate converted to linear gray channels between 6.7.6.7 and 6.7.8.2, # though probably not resolved until the latter # so -colorspace HSL/HSB -separate and -colorspace gray became linear # but we need to use -set colorspace RGB before using them at appropriate times # so that results stay as in original script # The following was determined from various version tests using redist. # Note: bug in IM 6.7.6.6 HSL/HSB bad, 6.7.7.0 HSL/HSB/RGB bad, 6.7.7.8 & 6.7.7.9 HSL/HSB bad, 6.7.8.1 HSB very bad if [ "$im_version" -lt "06070606" -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 # now do processing if convert -quiet "$infile" -strip +repage "$tmpA" then # get colorspace and type # add LC_ALL=C before sed to change language so that "bad" characters can be read without error colorspace=`$identifying -ping -verbose $tmpA | LC_ALL=C sed -n 's/^.*Colorspace: \([^ ]*\).*$/\1/p'` type=`$identifying -ping -verbose $tmpA | LC_ALL=C sed -n 's/^.*Type: \([^ ]*\).*$/\1/p'` [ "$type" = "Grayscale" ] && colorspace="Gray" # colormodel SRGB is processed the same as RGB [ "$colormodel" = "SRGB" ] && colormodel="RGB" # colormodels not valid for redist [ "$colormodel" = "HWB" -o "$colormodel" = "XYZ" -o "$colormodel" = "CMYK" ] && errMsg "--- $colormodel IS NOT A VALID COLORMODEL FOR REDIST ---" # if nothing supplied for channel, then set defaults if [ "$channel" = "" -a "$colormodel" = "HSL" ]; then channel=2 elif [ "$channel" = "" -a "$colormodel" = "HSB" ]; then channel=2 elif [ "$channel" = "" -a "$colormodel" = "HCL" ]; then channel=2 elif [ "$channel" = "" -a "$colormodel" != "RGB" -a "$colormodel" != "GLOBAL" -a "$colorspace" != "Gray" ]; then channel=0 fi #echo "colorspace=$colorspace; type=$type; channel=$channel; colormodel=$colormodel; graytype=$graytype; setcspace=$setcspace" if [ "$colorspace" != "Gray" -a "$channel" != "" -a "$colormodel" != "GLOBAL" ] then convert $tmpA $setcspace -colorspace $colormodel -channel R -separate $tmp0 convert $tmpA $setcspace -colorspace $colormodel -channel G -separate $tmp1 convert $tmpA $setcspace -colorspace $colormodel -channel B -separate $tmp2 elif [ "$colorspace" != "Gray" -a "$colormodel" = "RGB" -a "$graytype" = "GRAY" -a "$channel" = "" ] then convert $tmpA $setcspace -colorspace Gray $tmp2 elif [ "$colorspace" != "Gray" -a "$colormodel" = "RGB" -a "$graytype" = "REC709" -a "$channel" = "" ] then convert $tmpA $setcspace -colorspace Rec709Luma $tmp2 elif [ "$colorspace" != "Gray" -a "$colormodel" = "RGB" -a "$graytype" = "REC601" -a "$channel" = "" ] then convert $tmpA $setcspace -colorspace Rec601Luma $tmp2 elif [ "$colorspace" != "Gray" -a "$colormodel" = "RGB" -a "$graytype" = "LIGHTNESS" -a "$channel" = "" ] then convert $tmpA $setcspace -colorspace HSL -channel B -separate $tmp2 elif [ "$colorspace" != "Gray" -a "$colormodel" = "RGB" -a "$graytype" = "BRIGHTNESS" -a "$channel" = "" ] then convert $tmpA $setcspace -colorspace HSB -channel B -separate $tmp2 elif [ "$colorspace" != "Gray" -a "$colormodel" = "RGB" -a "$graytype" = "AVE" -a "$channel" = "" ] then convert $tmpA $setcspace -colorspace OHTA -channel R -separate $tmp2 elif [ "$colorspace" != "Gray" -a "$colormodel" = "RGB" -a "$graytype" = "AVE" -a "$channel" = "" ] then convert $tmpA $setcspace -colorspace LAB -channel R -separate $tmp2 elif [ "$colorspace" != "Gray" -a "$colormodel" = "RGB" -a "$graytype" = "LUMINANCE" -a "$channel" = "" ] then convert $tmpA -define modulate:colorspace=HSL -modulate 100,0,100 $tmp2 elif [ "$colorspace" != "Gray" -a "$colormodel" = "RGB" -a "$graytype" = "DEMODHCL" -a "$channel" = "" ] then convert $tmpA -define modulate:colorspace=HCL -modulate 100,0,100 $tmp2 elif [ "$colorspace" != "Gray" -a "$colormodel" = "GLOBAL" -a "$channel" = "" ] then convert $tmpA $setcspace -separate -append $tmp2 elif [ "$colorspace" = "Gray" ] then convert $tmpA $tmp2 else errMsg "--- UNKNOWN COLORSPACE OR COLORMODEL ---" fi else errMsg "--- FILE $infile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAS ZERO SIZE ---" fi #echo "" #echo "Please Wait - It May Take Some Time To Process The Image" #echo "" #echo "channel=$channel; colorspace=$colorspace; type=$type; colormodel=$colormodel;" # call subroutines [ "$channel" = "0" ] && convert $tmp0 $tmpP [ "$channel" = "1" ] && convert $tmp1 $tmpP [ "$channel" = "2" ] && convert $tmp2 $tmpP [ "$channel" = "" ] && convert $tmp2 $tmpP # for RGB, GLOBAL and colorspace gray cumHistogram "$tmpP" if [ "$shape" = "Uniform" -o "$shape" = "uniform" ] then genUniformLutArr else if [ "$shape" = "Gaussian" -o "$shape" = "gaussian" ] then gaussian fi integrateFunction genLutArr fi # now convert lutArr into lut image # Use NetPBM (PGM format implied intermediate image) # note, (somewhere in IM between 6.7.5.5 and 6.7.8.2) PGM is linear echo "P2 256 1 $maxval $lutlist" | convert - -scale 256x1\! $tmp3 # now process the input and recombine the color bands, if appropriate if [ "$colorspace" != "Gray" -a "$channel" != "" ] then # process one channel # need $tmpP to be non-linear, so use -set colorspace RGB if [ "$im_version" -ge "06030507" ] then convert $tmpP $tmp3 $setcspace -clut $tmpP else convert $tmpP $tmp3 $setcspace -fx 'v.p{u*v.w,0}' $tmpP fi # combine channels # channels are non-linear via -set colorspace RGB # so need to use -colorspace RGB to put them together # to reproduce original results. if [ $channel -eq 0 ] then convert $tmp0 -colorspace $colormodel \ $tmpP -compose CopyRed -composite \ $tmp1 -compose CopyGreen -composite \ $tmp2 -compose CopyBlue -composite \ -colorspace $cspace $outfile elif [ $channel -eq 1 ] then convert $tmp0 -colorspace $colormodel \ $tmp0 -compose CopyRed -composite \ $tmpP -compose CopyGreen -composite \ $tmp2 -compose CopyBlue -composite \ -colorspace $cspace $outfile elif [ $channel -eq 2 ] then convert $tmp0 -colorspace $colormodel \ $tmp0 -compose CopyRed -composite \ $tmp1 -compose CopyGreen -composite \ $tmpP -compose CopyBlue -composite \ -colorspace $cspace $outfile fi elif [ "$colorspace" != "Gray" -a "$colormodel" = "RGB" -a "$channel" = "" ] then # process RGB together if [ "$im_version" -ge "06030507" ] then convert $tmpA $tmp3 -clut $outfile else convert $tmpA $tmp3 -fx 'v.p{u*v.w,0}' "$outfile" fi elif [ "$colorspace" != "Gray" -a "$colormodel" = "GLOBAL" -a "$channel" = "" ] then # process RGB together if [ "$im_version" -ge "06030507" ] then convert $tmpA $tmp3 -clut "$outfile" else convert $tmpA $tmp3 -fx 'v.p{u*v.w,0}' "$outfile" fi else # process Grayscale if [ "$im_version" -ge "06030507" ] then convert $tmp2 $tmp3 $setcspace -clut $tmpP else convert $tmp2 $tmp3 $setcspace -fx 'v.p{u*v.w,0}' $tmpP fi convert $tmpP "$outfile" fi # now create histogram if [ $display_graph = "yes" ] then if [ "$colorspace" != "Gray" ] then if [ "$colormodel" = "RGB" -o "$colormodel" = "GLOBAL" ] then if [ "$im_version" -ge "06030507" ] then convert $tmp2 $tmp3 $setcspace -clut $tmpP else convert $tmp2 $tmp3 $setcspace -fx 'v.p{u*v.w,0}' $tmpP fi fi fi convert $tmpP -define histogram:unique-colors=false histogram:- | convert - -filter point -resize 128x100! $tmp4 if [ "$shape" != "Uniform" -a "$shape" != "uniform" ] then # now overlay graph on histogram; scale graph to 128 wide (take every other point) and 100 tall and invert the y coordinates i=0 while [ $i -lt 256 ] do x=`expr $i / 2` y=`echo "scale=0; 100 - (100 * ${functionArr[$i]} / $maxval)" | bc` pointArr[$x]="$x,$y" i=`expr $i + 2` done convert $tmp4 -stroke red -strokewidth 2 -fill none -draw "polyline ${pointArr[*]}" $tmp4 fi display $tmp4 fi [ "$savelut" = "yes" ] && convert $tmp3 redist_lut.png exit 0