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1 #!/bin/csh -f |
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2 # RCSid: $Id: psquish.csh,v 3.5 2008/11/10 19:08:19 greg Exp $ |
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3 set Lmin=.0001 # minimum visible world luminance |
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4 set Ldmin=1 # minimum display luminance |
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5 set Ldmax=100 # maximum display luminance |
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6 set nsteps=100 # number of steps in perceptual histogram |
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7 set cvratio=0.05 # fraction of pixels to ignore in envelope clipping |
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8 set td=/tmp |
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9 set tf0=$td/tf$$ |
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10 set tf1=$td/hist$$ |
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11 set tf1b=$td/hist$$.diff |
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12 set tf2=$td/cumt$$ |
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13 set tf3=$td/histeq$$.cal |
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14 set tf4=$td/cf$$.cal |
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15 set tf=($tf0 $tf1 $tf1b $tf2 $tf3 $tf4) |
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16 if ( "$argv[1]" == "-a" ) then |
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17 set adaptive |
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18 shift argv |
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19 endif |
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20 if ( $#argv != 1 ) then |
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21 echo "Usage: $0 [-a] input.hdr > output.hdr" |
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22 exit 1 |
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23 endif |
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24 set ifile=$1 |
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25 set ibase=$ifile:t |
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26 if ( "$ibase" =~ *.hdr ) set ibase=$ibase:r |
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27 set ibase=$ibase:t |
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28 onintr quit |
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29 pextrem -o $ifile > $tf0 |
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30 set Lmin=`rcalc -e 'L=179*(.265*$3+.67*$4+.065*$5)' -e 'cond=1.5-recno;$1=if('L-$Lmin,L,$Lmin')' $tf0` |
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31 set Lmax=`rcalc -e 'L=179*(.265*$3+.67*$4+.065*$5)' -e 'cond=recno-1.5;$1=if('$Ldmax-L,$Ldmax,L')' $tf0` |
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32 cat > $tf3 << _EOF_ |
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33 min(a,b) : if(a-b, b, a); |
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34 WE : 179; { Radiance white luminous efficacy } |
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35 Lmin : $Lmin ; { minimum visible luminance } |
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36 Lmax : $Lmax ; { maximum picture luminance } |
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37 Ldmin : $Ldmin ; { minimum output luminance } |
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38 Ldmax : $Ldmax ; { maximum output luminance } |
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39 Stepsiz : (Bl(Lmax)-Bl(Lmin))/ $nsteps ; { brightness step size } |
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40 { Logarithmic brightness function } |
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41 Bl(L) : log(L); |
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42 Lb(B) : exp(B); |
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43 BLw(Lw) : Bl(Ldmin) + (Bl(Ldmax)-Bl(Ldmin))*cf(Bl(Lw)); |
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44 { first derivative functions } |
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45 Bl1(L) : 1/L; |
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46 Lb1(B) : exp(B); |
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47 { histogram equalization function } |
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48 lin = li(1); |
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49 Lw = WE/le(1) * lin; |
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50 Lout = Lb(BLw(Lw)); |
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51 mult = if(Lw-Lmin, (Lout-Ldmin)/(Ldmax-Ldmin)/lin, 0) ; |
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52 _EOF_ |
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53 if ( $?adaptive ) then |
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54 cat >> $tf3 << _EOF_ |
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55 { Ferwerda contrast sensitivity function } |
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56 { log10 of cone threshold luminance } |
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57 ltp(lLa) : if(-2.6 - lLa, -.72, if(lLa - 1.9, lLa - 1.255, |
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58 (.249*lLa + .65)^2.7 - .72)); |
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59 { log10 of rod threshold luminance } |
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60 lts(lLa) : if(-3.94 - lLa, -2.86, if(lLa - -1.44, lLa - .395, |
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61 (.405*lLa + 1.6)^2.18 - 2.86)); |
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62 { threshold is minimum of rods and cones } |
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63 ldL2(lLa) : min(ltp(lLa),lts(lLa)); |
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64 dL(La) : 10^ldL2(log10(La)); |
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65 { derivative clamping function } |
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66 clamp2(L, bLw) : dL(Lb(bLw))/dL(L)/Lb1(bLw)/(Bl(Ldmax)-Bl(Ldmin))/Bl1(L); |
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67 clamp(L) : clamp2(L, BLw(L)); |
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68 { shift direction for histogram } |
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69 shiftdir(B) : if(cf(B) - (B - Bl(Lmin))/(Bl(Ldmax) - Bl(Lmin)), 1, -1); |
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70 { Scotopic/Photopic color adjustment } |
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71 sL(r,g,b) : .062*r + .608*g + .330*b; { approx. scotopic brightness } |
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72 BotMesopic : 10^-2.25; { top of scotopic range } |
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73 TopMesopic : 10^0.75; { bottom of photopic range } |
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74 incolor = if(Lw-TopMesopic, 1, if(BotMesopic-Lw, 0, |
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75 (Lw-BotMesopic)/(TopMesopic-BotMesopic))); |
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76 slf = (1 - incolor)*sL(ri(1),gi(1),bi(1)); |
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77 ro = mult*(incolor*ri(1) + slf); |
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78 go = mult*(incolor*gi(1) + slf); |
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79 bo = mult*(incolor*bi(1) + slf); |
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80 _EOF_ |
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81 else |
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82 cat >> $tf3 << _EOF_ |
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83 { derivative clamping function } |
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84 clamp2(L, bLw) : Lb(bLw)/L/Lb1(bLw)/(Bl(Ldmax)-Bl(Ldmin))/Bl1(L); |
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85 clamp(L) : clamp2(L, BLw(L)); |
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86 { shift direction for histogram } |
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87 shiftdir(B) : -1; |
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88 ro = mult*ri(1); |
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89 go = mult*gi(1); |
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90 bo = mult*bi(1); |
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91 _EOF_ |
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92 endif |
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93 # Compute brightness histogram |
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94 pfilt -1 -p 1 -x 128 -y 128 $ifile | pvalue -o -b -d -h -H \ |
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95 | rcalc -f $tf3 -e 'Lw=WE*$1;$1=if(Lw-Lmin,Bl(Lw),-1)' \ |
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96 | histo `ev "log($Lmin)" "log($Lmax)"` $nsteps > $tf1 |
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97 # Clamp frequency distribution |
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98 set totcount=`sed 's/^.*[ ]//' $tf1 | total` |
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99 set margin=`ev "floor($totcount*$cvratio+.5)"` |
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100 while ( 1 ) |
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101 # Compute mapping function |
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102 sed 's/^.*[ ]//' $tf1 | total -1 -r \ |
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103 | rcalc -e '$1=$1/'$totcount | rlam $tf1 - \ |
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104 | tabfunc -i 0 cf > $tf4 |
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105 # Compute difference with visible envelope |
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106 rcalc -f $tf4 -f $tf3 -e "T:$totcount*Stepsiz" \ |
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107 -e 'clfq=floor(T*clamp(Lb($1))+.5)' \ |
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108 -e '$1=$2-clfq;$2=shiftdir($1)' $tf1 > $tf1b |
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109 if (`sed 's/[ ].*$//' $tf1b | total` >= 0) then |
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110 # Nothing visible? -- just normalize |
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111 pfilt -1 -e `pextrem $ifile | rcalc -e 'cond=recno-1.5;$1=1/(.265*$3+.67*$4+.065*$5)'` $ifile |
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112 goto quit |
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113 endif |
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114 # Check to see if we're close enough |
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115 if (`rcalc -e '$1=if($1,$1,0)' $tf1b | total` <= $margin) break |
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116 # Squash frequency distribution |
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117 set diffs=(`sed 's/[ ].*$//' $tf1b`) |
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118 set shftd=(`sed 's/^.*[ ]//' $tf1b`) |
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119 while ( 1 ) |
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120 set maxi=0 |
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121 set maxd=0 |
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122 set i=$nsteps |
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123 while ( $i > 0 ) |
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124 if ( $diffs[$i] > $maxd ) then |
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125 set maxd=$diffs[$i] |
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126 set maxi=$i |
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127 endif |
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128 @ i-- |
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129 end |
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130 if ( $maxd == 0 ) break |
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131 set i=0 |
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132 tryagain: |
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133 set r=$shftd[$maxi] |
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134 while ( $i == 0 ) |
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135 @ t= $maxi + $r |
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136 if ( $t < 1 || $t > $nsteps ) then |
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137 @ shftd[$maxi]= -($shftd[$maxi]) |
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138 goto tryagain |
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139 endif |
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140 if ( $diffs[$t] < 0 ) set i=$t |
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141 @ r+= $shftd[$maxi] |
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142 end |
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143 if ( $diffs[$i] <= -$diffs[$maxi] ) then |
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144 @ diffs[$i]+= $diffs[$maxi] |
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145 set diffs[$maxi]=0 |
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146 else |
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147 @ diffs[$maxi]+= $diffs[$i] |
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148 set diffs[$i]=0 |
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149 endif |
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150 end |
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151 # Mung histogram |
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152 echo $diffs | tr ' ' '\012' | rlam $tf1 - \ |
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153 | rcalc -f $tf4 -f $tf3 -e "T:$totcount*Stepsiz" \ |
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154 -e 'clfq=floor(T*clamp(Lb($1))+.5)' \ |
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155 -e '$1=$1;$2=$3+clfq' > $tf1b |
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156 mv -f $tf1b $tf1 |
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157 end |
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158 # Plot the mapping function if we are in debug mode |
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159 if ( $?DEBUG ) then |
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160 cat > ${ibase}_histo.plt << _EOF_ |
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161 include=curve.plt |
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162 title="Brightness Frequency Distribution" |
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163 subtitle= $ibase |
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164 ymin=0 |
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165 xlabel="Perceptual Brightness B(Lw)" |
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166 ylabel="Frequency Count" |
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167 Alabel="Histogram" |
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168 Alintype=0 |
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169 Blabel="Envelope" |
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170 Bsymsize=0 |
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171 Adata= |
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172 _EOF_ |
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173 (cat $tf1; echo \;; echo Bdata=) >> ${ibase}_histo.plt |
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174 rcalc -f $tf4 -f $tf3 -e "T:$totcount*Stepsiz" \ |
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175 -e '$1=$1;$2=T*clamp(Lb($1))' $tf1 \ |
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176 >> ${ibase}_histo.plt |
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177 cat > ${ibase}_brmap.plt << _EOF_ |
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178 include=line.plt |
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179 title="Brightness Mapping Function" |
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180 subtitle= $ibase |
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181 xlabel="World Luminance (log cd/m^2)" |
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182 ylabel="Display Luminance (cd/m^2)" |
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183 ymax= $Ldmax |
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184 Adata= |
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185 _EOF_ |
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186 cnt 100 | rcalc -f $tf4 -f $tf3 -e '$1=lx;$2=Lb(BLw(10^lx))' \ |
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187 -e 'lx=$1/99*(log10(Lmax)-log10(Lmin))+log10(Lmin)' \ |
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188 >> ${ibase}_brmap.plt |
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189 if ( $?DISPLAY ) then |
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190 bgraph ${ibase}_histo.plt ${ibase}_brmap.plt | x11meta & |
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191 endif |
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192 endif |
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193 # Map our picture |
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194 getinfo < $ifile | egrep '^((VIEW|PIXASPECT|PRIMARIES)=|[^ ]*(rpict|rview|pinterp) )' |
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195 pcomb -f $tf4 -f $tf3 $ifile |
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196 quit: |
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197 rm -f $tf |