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authoryo mama <pepper@scannerjammer.com>2016-10-01 13:14:48 -0700
committeryo mama <pepper@scannerjammer.com>2016-10-01 13:14:48 -0700
commitd9b7653700040bf25cb5681b5dc7021bc505d975 (patch)
tree7422ce1db3c7b2a1ce5ac43f4b3093f81f13493e /bin/otsuthresh
parent6529b3767669476096fb30e69dcfd29773865a0c (diff)
added threshold scripts
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+#!/bin/bash
+#
+# Developed by Fred Weinhaus 10/29/2008 .......... revised 11/3/2015
+#
+# ------------------------------------------------------------------------------
+#
+# 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: otsuthresh [-g graph] infile outfile
+# USAGE: otsuthresh [-help]
+#
+# OPTIONS:
+#
+# -g graph graph specifies whether to generate a
+# histogram graph image displaying the
+# location and value of the threshold;
+# choices are: view or save;
+# default is no graph
+#
+###
+#
+# NAME: OTSUTHRESH
+#
+# PURPOSE: To automatically thresholds an image to binary (b/w) format
+# using Otsu's between class variance technique.
+#
+# DESCRIPTION: OTSUTHRESH automatically thresholds an image to binary
+# (b/w) format. It assume the histogram is bimodal, i.e. is the composite
+# of two bell-shaped distributions representing the foreground and
+# background classes. The Otsu appoach computes the Between Class Variance
+# from the foreground (above threshold data) and background (at and below
+# threshold value) for every possible threshold value. The optimal threshold
+# is the one that maximizes the Between Class Variance. This is equivalent
+# to finding the threshold that minimizes the overlap between the two
+# bell-shaped class curves.
+#
+# OPTIONS:
+#
+# -g graph ... GRAPH specifies whether to generate a graph (image) of
+# the histogram, displaying the location and value of the threshold.
+# The choices are: view, save and none. If graph=view is selected, the
+# graph will be created and displayed automatically, but not saved.
+# If graph=save is selected, then the graph will be created and saved
+# to a file using the infile name, with "_histog_otsu.gif" appended,
+# but the graph will not be displayed automatically. If -g option is
+# not specified, then no graph will be created.
+#
+# NOTE: It is highly recommended that the output not be specified
+# as a JPG image as that will cause compression and potentially a
+# non-binary (i.e. a graylevel) result. GIF is the recommended
+# output format.
+#
+# REFERENCES: see the following:
+# http://www.ph.tn.tudelft.nl/Courses/FIP/noframes/fip-Segmenta.html
+# http://homepages.inf.ed.ac.uk/rbf/CVonline/LOCAL_COPIES/MORSE/threshold.pdf
+# http://www.cse.unr.edu/~bebis/CS791E/Notes/Thresholding.pdf
+# http://www.ifi.uio.no/in384/info/threshold.ps
+# http://www.supelec.fr/ecole/radio/JPPS01.pdf
+#
+# 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
+graph="" #none, save or 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
+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
+ ;;
+ -g) # get graph
+ shift # to get the next parameter
+ # test if parameter starts with minus sign
+ errorMsg="--- INVALID GRAPH SPECIFICATION ---"
+ checkMinus "$1"
+ graph="$1"
+ [ "$graph" != "view" -a "$graph" != "save" ] && errMsg "--- GRAPH=$graph MUST BE EITHER VIEW OR SAVE ---"
+ ;;
+ -) # 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"
+
+# get outname from infile to use for graph
+inname=`convert $infile -format "%t" info:`
+histfile=${inname}_histog_otsu.gif
+
+tmpA1="$dir/otsuthresh_1_$$.mpc"
+tmpA2="$dir/otsuthresh_1_$$.cache"
+trap "rm -f $tmpA1 $tmpA2; exit 0" 0
+trap "rm -f $tmpA1 $tmpA2 $histfile; exit 1" 1 2 3 15
+
+# 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`
+
+# 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 otsuthresh.
+# with IM 6.7.4.10, 6.7.6.10, 6.7.8.10
+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 [ "$im_version" -gt "06080504" ]; then
+ setcspace=""
+fi
+
+
+if convert -quiet "$infile" $setcspace -colorspace gray +repage "$tmpA1"
+ then
+ : ' do nothing '
+else
+ errMsg "--- FILE $infile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAG ZERO SIZE ---"
+fi
+
+# get totpix in image
+width=`convert $tmpA1 -format "%w" info:`
+height=`convert $tmpA1 -format "%h" info:`
+totpix=`echo "scale=0; $width * $height / 1" | bc`
+
+ # get value array from IM histogram
+ valueArr=(`convert $tmpA1 -depth 8 -format "%c" -define histogram:unique-colors=true histogram:info:- \
+ | tr -cs '0-9\012' ' ' | sed -n 's/[ ]*\([0-9]*\)[ ]*\([0-9]*\).*$/\1 \2/p' |\
+ awk '
+ # AWK
+ { vbin[$2] += $2;}
+ END { for (i=0;i<256;i++) {print vbin[i]; } } '`)
+# echo ${valueArr[*]}
+# echo ${#valueArr[*]}
+ numvals=${#valueArr[*]}
+
+ # get count array from IM histogram
+ countArr=(`convert $tmpA1 -depth 8 -format "%c" -define histogram:unique-colors=true histogram:info:- \
+ | tr -cs '0-9\012' ' ' | sed -n 's/[ ]*\([0-9]*\)[ ]*\([0-9]*\).*$/\1 \2/p' |\
+ awk '
+ # AWK
+ { cbin[$2] += $1; }
+ END { for (i=0;i<256;i++) {print cbin[i]; } } '`)
+# echo ${countArr[*]}
+# echo ${#countArr[*]}
+ numcounts=${#countArr[*]}
+
+ [ $numvals -ne $numcounts ] && errMsg "--- NUMBER OF COUNTS IS NOT THE SAME AS NUMBER OF VALUES ---"
+
+ # compute normalized count array
+ ncountArr=( $(for ((i=0; i<$numcounts; i++)); do
+ echo "$i ${countArr[$i]}"
+ done |\
+ awk -v totpix="$totpix" -v numcounts="$numcounts" '
+ # AWK
+ { bin[$1] = $2; }
+ END { for (i=0;i<numcounts;i++) {print bin[i]/totpix; } } ') )
+# echo ${ncountArr[*]}
+# echo ${#ncountArr[*]}
+
+ # get global mean from values and normalized counts
+ mean=$( for ((i=0; i<$numcounts; i++)); do
+ echo "$i ${valueArr[$i]} ${ncountArr[$i]}"
+ done |\
+ awk -v numcounts="$numcounts" '
+ # AWK
+ { vbin[$1] = $2; ncbin[$1] = $3; }
+ END { for (i=0;i<numcounts;i++) { mean += vbin[i]*ncbin[i]; } print mean } ' )
+# echo "mean=$mean"
+
+
+#Generate Cumulative Arrays
+# p=c(i)/N (normalized count or probability, p, at bin i)
+# v=v(i) (graylevel at bin i)
+# t=threshold bin
+# n=p0=sum(c(i)/N)zeroth histogram moment => cumulative normalized count (from i=0 to t) = N(t)
+# g=p1=sum(c(i)*v(i))=first histogram momement => cumulative normalized graylevel (from i=0 to t) = G(t)
+
+
+ # compute nlowArr
+ nlowArr=( $(for ((i=0; i<$numcounts; i++)); do
+ echo "$i ${ncountArr[$i]}"
+ done |\
+ awk -v numcounts="$numcounts" '
+ # AWK to generate a cumulative histogram 1D image...
+ { nlowbin[$1] = $2; }
+ END { for (i=0;i<numcounts;i++) { nlow += nlowbin[i]; print nlow } } ') )
+# echo ${nlowArr[*]}
+# echo ${#nlowArr[*]}
+
+ # compute glowArr
+ glowArr=( $( for ((i=0; i<$numcounts; i++)); do
+ echo "$i ${valueArr[$i]} ${ncountArr[$i]}"
+ done |\
+ awk -v numcounts="$numcounts" '
+ # AWK to generate a cumulative histogram 1D image...
+ { vlowbin[$1] = $2; nclowbin[$1] = $3; }
+ END { for (i=0;i<numcounts;i++) { glow += vlowbin[i]*nclowbin[i]; print glow } } ') )
+# echo ${glowArr[*]}
+# echo ${#glowArr[*]}
+
+
+# Compute Threshold
+# loop through histogram using normalized counts and values
+# compute threshold by maximizing between class variance
+# bcv=Nl*(Ml-M)^2 + Nh*(Mh-M)^2 = (M*Nl-Gl)^2/(Nl*(1-Nl))
+
+# m=p1/p0=mean => M(t)=G(t)/N(t)
+# where Nh and Nl are normalized counts above and below threshold (zeroth moments, p0)
+# Mh and Ml are means of pixels above and below threshold
+# Gh and Gl are normalized cumulative graylevels (first moments, p1)
+# ML=Gl/Nl
+# above derived using
+# Nh=(1-Nl) for normalized histogram
+# Mh=(M-Ml*Nl)/(1-Nl) where M is overall mean of image
+
+
+ # compute threshold
+ #note: must stop at second to last bin so that nlow != 1 exactly or get divide by zero
+ threshbin=$(for ((i=0; i<$numcounts; i++)); do
+ echo "$i ${nlowArr[$i]} ${glowArr[$i]}"
+ done |\
+ awk -v numcounts="$numcounts" -v mean="$mean" -v bcvold=0 -v threshbin=0 '
+ # AWK to compute entropy threshold...
+ { nlowbin[$1] = $2; glowbin[$1] = $3; }
+ END { for (i=0;i<(numcounts-1);i++)
+ { dmean = (mean*nlowbin[i] - glowbin[i]); bcv = dmean*dmean/(nlowbin[i]*(1-nlowbin[i]));
+ if (bcv>bcvold) { bcvold=bcv; threshbin=i; } } print threshbin } ')
+# echo "threshbin=$threshbin"
+ thresh=${valueArr[$threshbin]}
+# echo "thresh=$thresh"
+ threshpct=`convert xc: -format "%[fx:100*$thresh/255]" info:`
+
+
+
+# compute threshold graph x coord and threshold in percent
+xx=$thresh
+threshpct=`convert xc: -format "%[fx:100*$thresh/255]" info:`
+#echo "xx=$xx; threshpct=$threshpct"
+
+
+echo "Thresholding Image At $threshpct%"
+convert $tmpA1 -threshold $threshpct% "$outfile"
+echo ""
+
+
+if [ "$graph" != "" ]; then
+ convert $tmpA1 -define histogram:unique-colors=false histogram:- | \
+ convert - -negate \
+ -stroke red -strokewidth 1 -draw "line $xx,0 $xx,200" \
+ -background gray -splice 0x30 \
+ -fill white -stroke white -strokewidth 1 \
+ -font ArialB -pointsize 24 \
+ -draw "text 4,22 'threshold=$threshpct%'" -resize 50% \
+ -bordercolor gray50 -border 5 \
+ "$histfile"
+fi
+
+if [ "$graph" = "view" ]; then
+ convert "$histfile" x:
+ rm -f "$histfile"
+fi
+
+exit 0
+
+
+