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#!/bin/csh -f |
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# RCSid: $Id: phisteq.csh,v 3.3 2005/02/16 05:40:11 greg Exp $ |
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set Ldmin=1 # minimum display luminance |
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set Ldmax=100 # maximum display luminance |
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set nsteps=100 # number of steps in perceptual histogram |
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set cvratio=0.08 # fraction of pixels to ignore in envelope clipping |
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set td=/tmp |
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set tf1=$td/hist$$ |
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set tf1b=$td/hist$$.new |
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set tf2=$td/cumt$$ |
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set tf3=$td/histeq$$.cal |
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set tf4=$td/cf$$.cal |
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set tf=($tf1 $tf1b $tf2 $tf3 $tf4) |
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if ( $#argv != 1 ) then |
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echo "Usage: $0 input.hdr > output.hdr" |
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exit 1 |
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endif |
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set ifile=$1 |
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set ibase=$ifile:t |
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if ( "$ibase" =~ *.pic ) set ibase=$ibase:r |
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set ibase=$ibase:t |
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onintr quit |
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cat > $tf3 << _EOF_ |
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WE : 179; { Radiance white luminous efficacy } |
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Lmin : .0001; { minimum allowed luminance } |
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Ldmin : $Ldmin ; { minimum output luminance } |
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Ldmax : $Ldmax ; { maximum output luminance } |
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Stepsiz : 1/ $nsteps ; { brightness step size } |
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{ Daly local amplitude nonlinearity formulae } |
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sq(x) : x*x; |
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c1 : 12.6; |
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b : .63; |
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Bl(L) : L / (L + (c1*L)^b); |
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Lb(B) : (c1^b*B/(1-B))^(1/(1-b)); |
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BLw(Lw) : Bl(Ldmin) + (Bl(Ldmax)-Bl(Ldmin))*cf(Bl(Lw)); |
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{ first derivative functions } |
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Bl1(L) : (c1*L)^b*(1-b)/sq(L + (c1*L)^b); |
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Lb1(B) : c1^b/(1-b)/sq(1-B) * (c1^b*B/(1-B))^(b/(1-b)); |
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{ derivative clamping function } |
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clamp2(L, aLw) : Lb(aLw) / L / Lb1(aLw) / (Bl(Ldmax)-Bl(Ldmin)) / Bl1(L); |
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clamp(L) : clamp2(L, BLw(L)); |
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{ histogram equalization function } |
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lin = li(1); |
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Lw = WE/le(1) * lin; |
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Lout = Lb(BLw(Lw)); |
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mult = if(Lw-Lmin, (Lout-Ldmin)/(Ldmax-Ldmin)/lin, 0) ; |
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ro = mult * ri(1); |
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go = mult * gi(1); |
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bo = mult * bi(1); |
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_EOF_ |
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# Compute brightness histogram |
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pfilt -1 -p 1 -x 128 -y 128 $ifile | pvalue -o -b -d -h -H \ |
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| rcalc -f $tf3 -e 'Lw=WE*$1;$1=if(Lw-Lmin,Bl(Lw),-1)' \ |
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| histo 0 1 $nsteps | sed '/[ ]0$/d' > $tf1 |
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# Clamp frequency distribution |
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set totcount=`sed 's/^.*[ ]//' $tf1 | total` |
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set tst=1 |
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while ( $totcount > 0 ) |
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sed 's/^.*[ ]//' $tf1 | total -1 -r \ |
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| rcalc -e '$1=$1/'$totcount | rlam $tf1 - \ |
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| tabfunc -i 0 cf > $tf4 |
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if ( $tst <= 0 ) break |
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rcalc -f $tf4 -f $tf3 -e "T:$totcount*Stepsiz" \ |
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-e 'clfq=floor(T*clamp(Lb($1)))' \ |
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-e '$1=$1;$2=if($2-clfq,clfq,$2)' $tf1 > $tf1b |
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set newtot=`sed 's/^.*[ ]//' $tf1b | total` |
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set tst=`ev "floor((1-$cvratio)*$totcount)-$newtot"` |
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mv -f $tf1b $tf1 |
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set totcount=$newtot |
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end |
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if ( $totcount < 1 ) then |
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# Fits in display range nicely already -- just normalize |
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pfilt -1 -e `pextrem $ifile | rcalc -e 'cond=recno-1.5;$1=1/(.265*$3+.67*$4+.065*$5)'` $ifile |
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else |
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# Plot the mapping function if we are in debug mode |
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if ( $?DEBUG ) then |
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cat > ${ibase}_histo.plt << _EOF_ |
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include=curve.plt |
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title="Brightness Frequency Distribution" |
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subtitle= $ibase |
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ymin=0 |
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xlabel="Perceptual Brightness B(Lw)" |
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ylabel="Frequency Count" |
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Alabel="Histogram" |
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Alintype=0 |
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Blabel="Envelope" |
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Bsymsize=0 |
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Adata= |
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_EOF_ |
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(cat $tf1; echo \;; echo Bdata=) >> ${ibase}_histo.plt |
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rcalc -f $tf4 -f $tf3 -e "T:$totcount*Stepsiz" \ |
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-e '$1=$1;$2=T*clamp(Lb($1))' $tf1 \ |
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>> ${ibase}_histo.plt |
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cat > ${ibase}_brmap.plt << _EOF_ |
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include=line.plt |
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title="Brightness Mapping Function" |
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subtitle= $ibase |
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xlabel="World Luminance (log cd/m^2)" |
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ylabel="Display Luminance (cd/m^2)" |
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ymax= $Ldmax |
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Adata= |
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_EOF_ |
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cnt 100 | rcalc -f $tf4 -f $tf3 -e '$1=lx;$2=Lb(BLw(10^lx))' \ |
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-e Lmin:Lb\(`sed -n '1s/[ ].*$//p' $tf1`\) \ |
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-e Lmax:Lb\(`sed -n '$s/[ ].*$//p' $tf1`\) \ |
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-e 'lx=$1/99*(log10(Lmax)-log10(Lmin))+log10(Lmin)' \ |
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>> ${ibase}_brmap.plt |
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if ( $?DISPLAY ) then |
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bgraph ${ibase}_histo.plt ${ibase}_brmap.plt | x11meta & |
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endif |
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endif |
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# Map our picture |
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pcomb -f $tf4 -f $tf3 $ifile |
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endif |
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quit: |
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rm -f $tf |
