1 #!/usr/bin/perl

     2 #

     3 # Compute 1976 CIE Lab deltaE* between two Radiance pictures

     4 #

     5 # This is a re-write of Greg's pdelta.csh script

     6 

     7 use strict;

     8 use warnings;

     9 use File::Temp qw/ tempdir /;

    10 

    11 if($#ARGV != 1) {

    12 	print "Usage: $0 pic1.hdr pic2.hdr > output.hdr";

    13 	exit(1);

    14 }

    15 

    16 my $cielab = 'sq(x):x*x;';

    17 $cielab .= 'Ls(Yi):if(Yi/Yw-.01,116*(Yi/Yw)^(1/3)-16,903.3*Yi/Yw);';

    18 $cielab .= 'as(Xi,Yi,Zi):500*((Xi/Xw)^(1/3)-(Yi/Yw)^(1/3));';

    19 $cielab .= 'bs(Xi,Yi,Zi):200*((Yi/Yw)^(1/3)-(Zi/Zw)^(1/3));';

    20 $cielab .= 'dE(X1,Y1,Z1,X2,Y2,Z2):sqrt(sq(Ls(Y1)-Ls(Y2))+sq(as(X1,Y1,Z1)';

    21 $cielab .= '-as(X2,Y2,Z2))+sq(bs(X1,Y1,Z1)-bs(X2,Y2,Z2)))';

    22 

    23 # The following is for Radiance RGB -> XYZ

    24 my $rgb2xyz = 'X(R,G,B):92.03*R+57.98*G+28.99*B;';

    25 $rgb2xyz .= 'Y(R,G,B):47.45*R+119.9*G+11.6*B;';

    26 $rgb2xyz .= 'Z(R,G,B):4.31*R+21.99*G+152.7*B';

    27 

    28 # The following is for sRGB -> XYZ

    29 my $f1 = "$ARGV[0]";

    30 my $inp1 = 'x1=ri(1);y1=gi(1);z1=bi(1)';

    31 my $f2 = "$ARGV[1]";

    32 my $inp2 = 'x2=ri(2);y2=gi(2);z2=bi(2)';

    33 

    34 # Make sure both images are in XYZE format

    35 `getinfo < $f1 | grep '^FORMAT=32-bit_rle_xyze'`;

    36 # Exit status: 0 if no error (string is found -> image is in XYZE format)

    37 if( $? != 0 ) {

    38 	$inp1 = 'x1=X(ri(1),gi(1),bi(1));';

    39 	$inp1 .= 'y1=Y(ri(1),gi(1),bi(1));';

    40 	$inp1 .= 'z1=Z(ri(1),gi(1),bi(1))';

    41 }

    42 

    43 `getinfo < $f2 | grep '^FORMAT=32-bit_rle_xyze'`;

    44 if( $? != 0 ) {

    45 	$inp2 = 'x2=X(ri(2),gi(2),bi(2));';

    46 	$inp2 .= 'y2=Y(ri(2),gi(2),bi(2));';

    47 	$inp2 .= 'z2=Z(ri(2),gi(2),bi(2))';

    48 }

    49 

    50 my $td = tempdir( CLEANUP => 1 );

    51 my $tempf = "$td/tf.hdr";

    52 

    53 system "pfilt -1 -x 128 -y 128 -p 1 $f1 | pvalue -o -h -H -d > $tempf";

    54 my @wht = split(/\s+/, `total -u $tempf`);

    55 my $avg = `rcalc -e '\$1=\$2' $tempf | total -m`;

    56 chomp $avg;

    57 

    58 my $cmd = "pcomb -e '$cielab' -e '$rgb2xyz' ";

    59 $cmd .= "-e 'Yw:179*3*$avg; Xw:$wht[0]*Yw/$wht[1]; Zw:$wht[2]*Yw/$wht[1]' ";

    60 $cmd .= "-e '$inp1' -e '$inp2' -e 'lo=dE(x1,y1,z1,x2,y2,z2)' ";

    61 $cmd .= "-o $f1 -o $f2";

    62 

    63 system $cmd;

    64 

    65 #EOF