#!/bin/bash # # Developed by Fred Weinhaus 10/2/2017 .......... revised 12/9/2018 # # ------------------------------------------------------------------------------ # # 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: adaptivegamma [-t type] [-c colormode] [-a autolevel] [-s sigma] [-m mix ] # [-b base] [-g gain] [-T thresh] infile outfile # USAGE: adaptivegamma [-h or -help] # # OPTIONS: # # -t type type of adaptive gamma enhancement; choices are lcc, pnae, hybrid; # default=hybrid # -c colormode colorspace for processing; choices are gray, srgb, lab, hcl, hsl, # hsv, hsi, ycbcr and ohta; default=gray # -a autolevel autolevel as preprocessing; options are: off, together and # separately; default=together # -s sigma sigma value for blurring the intensity-like channel; integer>=0; # default=20 # -m mix mixing percent for the hybrid blend of lcc and pnae; # 0<=integer<= 100; default=50; 0 is pure lcc, 100 is pure pnae # -b base base value for lcc method; float>0; default=2 # -g gain gain value for pnae method; float>=0; default is computed # automatically from the mean and standard deviation of the image; # nominal value is about 0.5 # -T thresh threshold to determine if image is bright or dark; 0<=float<=1; # default=0.5. If bright, the image will be negated before and # after processing # ### # # NAME: ADAPTIVEGAMMA # # PURPOSE: To enhance the contrast/brightness in an image using an adaptive gamma method. # # DESCRIPTION: ADAPTIVEGAMMA is a locally/spatially adaptive gamma technique to enhance # an image's brightness and contrast. There are 3 types of adaptive gamma enhancement # that can be used. The first is the local contrast correction (lcc) method. The second # is the parallel nonlinear adaptive enhancement (pnae) method. The third is a hybrid # blend of the other two. # # These adaptive gamma methods are power law adjustments of the image as defined by # OUT=pow(IN,exponent); where exponent = 1/gamma. However, here the exponent is a value # that changes spatially according to the local mean M(x,y) of the intensity-like # channel of the image. # # In the lcc method, exponent=[base]*M(x,y)-1, where M is an image of the local mean of the # intensity-like channel achieve by blurring the image and base is nominally 2. # # In the pnae method, exponent=const*[M(x,y)-epsilon]/[1-M(x,y)+epsilon] + gain. The # const and epsilon values are constants where const=0.1 and epsilon=0.01. The gain is # essentially a global (inverse) gamma value and is nominally about 0.5. But here the # default is computed automatically as (log(0.5)/log(M))*($maxstd/min($maxstd,S)), # where M is the global mean of the image and S is the global standard deviation of # the image and maxstd is a maximum value for the standard deviation above which the # standard deviation term equals unity and so does not affect the first mean term. # # Arguments: # # -t type ... TYPE of adaptive gamma enhancement. The choices are lcc (l), pnae (p) # and hybrid (h). The default=hybrid. # # -c colormode ... COLORMODE is the colorspace for processing. The choices are gray, # srgb, lab, hcl, hsl, hsv, hsi, ycbcr and ohta. The default=gray. # # -a autolevel ... AUTOLEVEL as preprocessing step. The choices are: off (o), # together (t) and separately (s). The default=together # # -s sigma ... SIGMA value for blurring the intensity-like channel. Values are # integer>=0. The default=20. Larger values give slightly more contrast. # # -m mix ... MIX is the mixing percent for the hybrid blend of the lcc and pnae types. # Values are 0<=integers<= 100. The default=50. 0 is pure lcc and 100 is pure pnae. # # -b base .. BASE value for lcc method. Values are floats>0. The default=2. Larger # values reduce the contrast and smaller values increase the contrast. # # -g gain ... GAIN value for pnae method. Values aare float>=0. The default is computed # automatically from the global mean and standard deviation of the intensity-like # channel of the image. The nominal value is around 0.5. # # -T thresh ... THRESH is a threshold to determine if the image is bright or dark. # Values are 0<=float<=1. The default=0.5. If bright, the image will be negated before # and after processing. # # REFERENCES: # http://www.ipol.im/pub/art/2011/gl_lcc/article_lr.pdf # https://asp-eurasipjournals.springeropen.com/track/pdf/10.1186/1687-6180-2014-70?site=asp.eurasipjournals.springeropen.com # https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwigiqGb1sjWAhXrlVQKHSM3Bf4QFggrMAE&url=http%3A%2F%2Fwww.ivl.disco.unimib.it%2Fdownload%2Fcapra2010contrast-image.pdf&usg=AFQjCNFcvsunTdhTjNTd6goxo3wZCPvEYQ # https://en.wikipedia.org/wiki/Gamma_correction # # NOTE: This script may be a bit slow due to the use of -fx. # # 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 # external args type="hybrid" #lcc, pnae, hybrid colormode="gray" # gray, srgb, lab, hcl, ycbcr, ohta autolevel="together" # together or separate or off sigma=20 # blur sigma mix=0.5 # mixing of lcc and pnae for hybrid (mix=1 is pnae, mix=0 is lcc) base=2 # for lcc and hybrid gain="" # nominal 0.5, default computed from mean and midgray thresh=0.5 # threshold to determine if image is bright or dark # internal args midgray=0.5 # for lcc or hybrid maxstd=0.15 # for lcc or hybrid const=0.1 # for pnae or hybrid eps=0.01 # for pnae or hybrid # 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 18 ] then errMsg "--- TOO MANY ARGUMENTS WERE PROVIDED ---" else while [ $# -gt 0 ] do # get parameters case "$1" in -h|-help) # help information echo "" usage2 ;; -t) # get type shift # to get the next parameter # test if parameter starts with minus sign errorMsg="--- INVALID TYPE SPECIFICATION ---" checkMinus "$1" type=`echo "$1" | tr '[A-Z]' '[a-z]'` case "$type" in lcc|l) type="lcc" ;; pnae|p) type="pnae" ;; hybrid|h) type="hybrid" ;; *) errMsg "--- TYPE=$type IS AN INVALID VALUE ---" ;; esac ;; -a) # get autolevel shift # to get the next parameter # test if parameter starts with minus sign errorMsg="--- INVALID AUTOLEVEL SPECIFICATION ---" checkMinus "$1" autolevel=`echo "$1" | tr '[A-Z]' '[a-z]'` case "$autolevel" in off|o) autolevel="off" ;; together|t) autolevel="together" ;; separately|s) autolevel="separately" ;; *) errMsg "--- AUTOLEVEL=$autolevel IS AN INVALID VALUE ---" ;; esac ;; -c) # get colormode shift # to get the next parameter # test if parameter starts with minus sign errorMsg="--- INVALID COLORMODE SPECIFICATION ---" checkMinus "$1" colormode=`echo "$1" | tr '[A-Z]' '[a-z]'` case "$colormode" in gray|g) colormode="gray" ;; srgb|s|r) colormode="srgb" ;; lab|l) colormode="lab" ;; hcl) colormode="hcl" ;; hsl) colormode="hsl" ;; hsv) colormode="hsv" ;; hsi) colormode="hsi" ;; ycbcr|y) colormode="ycbcr" ;; ohta|o) colormode="ohta" ;; *) errMsg "--- COLORMODE=$colormode IS AN INVALID VALUE ---" ;; esac ;; -s) # get sigma shift # to get the next parameter # test if parameter starts with minus sign errorMsg="--- INVALID SIGMA SPECIFICATION ---" checkMinus "$1" sigma=`expr "$1" : '\([0-9]*\)'` [ "$sigma" = "" ] && errMsg "--- SIGMA=$sigma MUST BE A NON-NEGATIVE INTEGER ---" ;; -m) # get mix shift # to get the next parameter # test if parameter starts with minus sign errorMsg="--- INVALID MIX SPECIFICATION ---" checkMinus "$1" mix=`expr "$1" : '\([0-9]*\)'` [ "$mix" = "" ] && errMsg "--- MIX=$mix MUST BE A NON-NEGATIVE INTEGER ---" testA=`echo "$mix > 100" | bc` [ $testA -eq 1 ] && errMsg "--- MIX=$mix MUST BE AN INTEGER BETWEEN 0 AND 100 ---" ;; -b) # base shift # to get the next parameter - maxgain # test if parameter starts with minus sign errorMsg="--- INVALID BASE SPECIFICATION ---" checkMinus "$1" base=`expr "$1" : '\([.0-9]*\)'` [ "$base" = "" ] && errMsg "--- BASE=$base MUST BE A POSITIVE FLOATING POINT VALUE (with no sign) ---" testA=`echo "$base == 0" | bc` [ $testA -eq 1 ] && errMsg "--- BASE=$base MUST BE A POSITIVE FLOATING POINT VALUE ---" ;; -g) # gain shift # to get the next parameter - maxgain # test if parameter starts with minus sign errorMsg="--- INVALID GAIN SPECIFICATION ---" checkMinus "$1" gain=`expr "$1" : '\([.0-9]*\)'` [ "$gain" = "" ] && errMsg "--- GAIN=$gain MUST BE A POSITIVE FLOATING POINT VALUE (with no sign) ---" ;; -T) # thresh shift # to get the next parameter - maxgain # test if parameter starts with minus sign errorMsg="--- INVALID THRESH SPECIFICATION ---" checkMinus "$1" thresh=`expr "$1" : '\([.0-9]*\)'` [ "$thresh" = "" ] && errMsg "--- THRESH=$thresh MUST BE A POSITIVE FLOATING POINT VALUE (with no sign) ---" testA=`echo "$thresh > 1" | bc` [ $testA -eq 1 ] && errMsg "--- THRESH=$thresh MUST BE A POSITIVE FLOATING POINT VALUE BETWEEN 0 AND 1 ---" ;; -) # 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 [ "$outfile" = "" ] && errMsg "NO OUTPUT FILE SPECIFIED" # setup temporary images tmpA1="$dir/space3_1_$$.mpc" tmpB1="$dir/space3_1_$$.cache" trap "rm -f $tmpA1 $tmpB1; exit 0" 0 trap "rm -f $tmpA1 $tmpB1; exit 1" 1 2 3 15 # set up autolevel if [ "$autolevel" = "separate" ]; then aproc="-channel rgb -auto-level" elif [ "$autolevel" = "together" ]; then aproc="-auto-level" else aproc="" fi # test threshold for negating if image is too bright test=`convert "$infile" -format "%[fx:mean>$thresh?1:0]" info:` if [ $test -eq 1 ]; then negating="-negate" else negating="" fi # read the input image into the temporary cached image and test if valid convert -quiet -regard-warnings "$infile" $negating $aproc +repage $tmpA1 || echo "--- 1 FILE $infile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAS ZERO size ---" # set up gain if [ "$type" != "lcc" -a "$gain" = "" ]; then # gain=inverse gamma with boost for very low standard deviations (very low contrast) #gain=`convert $tmpA1 -format "%[fx:log(0.5)/log(mean)]" info:` gain=`convert $tmpA1 -format "%[fx:(log($midgray)/log(mean))*($maxstd/min($maxstd,standard_deviation))]" info:` fi #echo "gain=$gain" # convert mix to fraction mix=`convert xc: -format "%[fx:$mix/100]" info:` # set up channel for colormode [ "$colormode" = "lab" -o "$colormode" = "ycbcr" -o "$colormode" = "ohta" ] && channel=0 [ "$colormode" = "hcl" -o "$colormode" = "hsl" -o "$colormode" = "hsv" -o "$colormode" = "hsi" ] && channel=2 if [ "$type" = "lcc" ] || [ "$type" = "hybrid" -a "$mix" = "0" ]; then if [ "$colormode" = "gray" ]; then convert $tmpA1 \( +clone -colorspace $colormode -blur 0x$sigma \) -monitor \ -fx "pow(u,pow($base,2*v-1))" +monitor $negating "$outfile" elif [ "$colormode" = "srgb" ]; then convert $tmpA1 -colorspace sRGB -separate \ \( -clone 0 \( +clone -blur 0x$sigma \) -monitor -fx "pow(u,pow($base,2*v-1))" +monitor \) \ \( -clone 1 \( +clone -blur 0x$sigma \) -monitor -fx "pow(u,pow($base,2*v-1))" +monitor \) \ \( -clone 2 \( +clone -blur 0x$sigma \) -monitor -fx "pow(u,pow($base,2*v-1))" +monitor \) \ -delete 0-2 -set colorspace sRGB -combine -colorspace sRGB $negating \ "$outfile" else convert $tmpA1 -colorspace $colormode -separate \ \( -clone $channel \( +clone -blur 0x$sigma \) -monitor -fx "pow(u,pow($base,2*v-1))" +monitor \) \ -swap ${channel},3 +delete -set colorspace $colormode -combine -colorspace sRGB $negating \ "$outfile" fi elif [ "$type" = "pnae" ] || [ "$type" = "hybrid" -a "$mix" = "1" ]; then if [ "$colormode" = "gray" ]; then convert $tmpA1 \( +clone -colorspace $colormode -blur 0x$sigma \) -monitor \ -fx "pow(u,$const*(v+$eps)/(1-v+$eps)+$gain)" +monitor $negating "$outfile" elif [ "$colormode" = "srgb" ]; then convert $tmpA1 -colorspace sRGB -separate \ \( -clone 0 \( +clone -blur 0x$sigma \) -monitor -fx "pow(u,$const*(v+$eps)/(1-v+$eps)+$gain)" +monitor \) \ \( -clone 1 \( +clone -blur 0x$sigma \) -monitor -fx "pow(u,$const*(v+$eps)/(1-v+$eps)+$gain)" +monitor \) \ \( -clone 2 \( +clone -blur 0x$sigma \) -monitor -fx "pow(u,$const*(v+$eps)/(1-v+$eps)+$gain)" +monitor \) \ -delete 0-2 -set colorspace sRGB -combine -colorspace sRGB $negating \ "$outfile" else convert $tmpA1 -colorspace $colormode -separate \ \( -clone $channel \( +clone -blur 0x$sigma \) -monitor -fx "pow(u,$const*(v+$eps)/(1-v+$eps)+$gain)" +monitor \) \ -swap ${channel},3 +delete -set colorspace $colormode -combine -colorspace sRGB $negating \ "$outfile" fi elif [ "$type" = "hybrid" ]; then if [ "$colormode" = "gray" ]; then convert $tmpA1 \( +clone -colorspace $colormode -blur 0x$sigma \) -monitor \ -fx "pow(u,$mix*($const*(v+$eps)/(1-v+$eps)+$gain)+(1-$mix)*pow($base,2*v-1))" +monitor $negating "$outfile" elif [ "$colormode" = "srgb" ]; then convert $tmpA1 -colorspace sRGB -separate \ \( -clone 0 \( +clone -blur 0x$sigma \) -monitor -fx "pow(u,$mix*($const*(v+$eps)/(1-v+$eps)+$gain)+(1-$mix)*pow($base,2*v-1))" +monitor \) \ \( -clone 1 \( +clone -blur 0x$sigma \) -monitor -fx "pow(u,$mix*($const*(v+$eps)/(1-v+$eps)+$gain)+(1-$mix)*pow($base,2*v-1))" +monitor \) \ \( -clone 2 \( +clone -blur 0x$sigma \) -monitor -fx "pow(u,$mix*($const*(v+$eps)/(1-v+$eps)+$gain)+(1-$mix)*pow($base,2*v-1))" +monitor \) \ -delete 0-2 -set colorspace sRGB -combine -colorspace sRGB $negating \ "$outfile" else convert $tmpA1 -colorspace $colormode -separate \ \( -clone $channel \( +clone -blur 0x$sigma \) -monitor -fx "pow(u,$mix*($const*(v+$eps)/(1-v+$eps)+$gain)+(1-$mix)*pow($base,2*v-1))" +monitor \) \ -swap ${channel},3 +delete -set colorspace $colormode -combine -colorspace sRGB $negating \ "$outfile" fi fi exit 0