package Image::TIFF;
# Copyright 1999-2001, Gisle Aas.
#
# This library is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.
use strict;
use vars qw($VERSION);
$VERSION = '1.00';
my @types = (
[ "BYTE", "C1", 1],
[ "ASCII", "A1", 1],
[ "SHORT", "n1", 2],
[ "LONG", "N1", 4],
[ "RATIONAL", "N2", 8],
[ "SBYTE", "c1", 1],
[ "UNDEFINED", "a1", 1],
[ "SSHORT", "n1", 2],
[ "SLONG", "N1", 4],
[ "SRATIONAL", "N2", 8],
[ "FLOAT", "f1", 4], # XXX 4-byte IEEE format
[ "DOUBLE", "d1", 8], # XXX 8-byte IEEE format
);
my %nikon1_tags = (
0x0003 => "Quality",
0x0004 => "ColorMode",
0x0005 => "ImageAdjustment",
0x0006 => "CCDSensitivity",
0x0007 => "Whitebalance",
0x0008 => "Focus",
0x000A => "DigitalZoom",
0x000B => "Converter",
);
my %nikon2_tags = (
0x0002 => "ISOSetting",
0x0003 => "ColorMode",
0x0004 => "Quality",
0x0005 => "Whitebalance",
0x0006 => "ImageSharpening",
0x0007 => "FocusMode",
0x0008 => "FlashSetting",
0x000F => "ISOSelection",
0x0080 => "ImageAdjustment",
0x0082 => "AuxiliaryLens",
0x0085 => "ManualFocusDistance",
0x0086 => "DigitalZoom",
0x0088 => { __TAG__ => "AFFocusPosition",
pack("xCxx",0) => "Center",
pack("xCxx",1) => "Top",
pack("xCxx",2) => "Bottom",
pack("xCxx",3) => "Left",
pack("xCxx",4) => "Right",
},
0x0010 => "DataDump",
);
my %olympus_tags = (
0x0200 => "SpecialMode",
0x0201 => { __TAG__ => "JpegQual", 1 => "SQ", 2 => "HQ", 3 => "SHQ" },
0x0202 => { __TAG__ => "Macro", 0 => "Normal", 1 => "Macro" },
0x0204 => "DigiZoom",
0x0207 => "SoftwareRelease",
0x0208 => "PictInfo",
0x0209 => "CameraID",
0x0f00 => "DataDump",
);
my %fujifilm_tags = (
0x0000 => "Version",
0x1000 => "Quality",
0x1001 => { __TAG__ => "Sharpness",
1 => "Very Soft",
2 => "Soft",
3 => "Normal",
4 => "Hard",
5 => "Very Hard",
},
0x1002 => { __TAG__ => "WhiteBalance",
0 => "Auto",
256 => "Daylight",
512 => "Cloudy",
768 => "DaylightColor-fluorescence",
769 => "DaywhiteColor-fluorescence",
770 => "White-fluorescence",
1024 => "Incandenscense",
3840 => "Custom white balance",
},
0x1003 => { __TAG__ => "Color", 0 => "Normal", 256 => "High", 512 => "Low" },
0x1004 => { __TAG__ => "Tone" , 0 => "Normal", 256 => "High", 512 => "Low" },
0x1010 => { __TAG__ => "FlashMode", 0 => "Auto", 1 => "On", 2 => "Off", 3 => "Red-eye reduction" },
0x1011 => "FlashStrength",
0x1020 => { __TAG__ => "Macro", 0 => "Off", 1 => "On"},
0x1021 => { __TAG__ => "FocusMode", 0 => "Auto", 1 => "Manual" },
0x1030 => { __TAG__ => "SlowSync", 0 => "Off", 1 => "On"},
0x1031 => { __TAG__ => "PictureMode",
0 => "Auto",
1 => "Portrait",
2 => "Landscape",
4 => "Sports",
5 => "Night",
6 => "Program AE",
256 => "Aperture priority",
512 => "Shutter priority",
768 => "Manual",
},
0x1100 => { __TAG__ => "AutoBracketing", 0 => "Off", 1 => "On"},
0x1300 => { __TAG__ => "BlurWarning", 0 => "No", 1 => "Yes"},
0x1301 => { __TAG__ => "FocusWarning", 0 => "No", 1 => "Yes"},
0x1302 => { __TAG__ => "AEWarning", 0 => "No", 1 => "Yes"},
);
my %casio_tags = (
0x0001 => { __TAG__ => "RecordingMode",
1 => "SingleShutter",
2 => "Panorama",
3 => "Night scene",
4 => "Portrait",
5 => "Landscape",
},
0x0002 => { __TAG__ => "Quality", 1 => "Economy", 2 => "Normal", 3 => "Fine" },
0x0003 => { __TAG__ => "FocusingMode",
2 => "Macro",
3 => "Auto",
4 => "Manual",
5 => "Infinity",
},
0x0004 => { __TAG__ => "FlashMode", 1 => "Auto", 2 => "On", 3 => "Off", 4 => "Red-eye reduction" },
0x0005 => { __TAG__ => "FlashIntensity", 11 => "Weak", 13 => "Normal", 15 => "Strong" },
0x0006 => "ObjectDistance",
0x0007 => { __TAG__ => "WhiteBalance",
1 => "Auto",
2 => "Tungsten",
3 => "Daylight",
4 => "Fluorescent",
5 => "Shade",
129 => "Manual",
},
0x000a => { __TAG__ => "DigitalZoom", 65536 => "Off", 65537 => "2X" },
0x000b => { __TAG__ => "Sharpness", 0 => "Normal", 1 => "Soft", 2 => "Hard" },
0x000c => { __TAG__ => "Contrast" , 0 => "Normal", 1 => "Low", 2 => "High" },
0x000d => { __TAG__ => "Saturation", 0 => "Normal", 1 => "Low", 2 => "High" },
0x0014 => { __TAG__ => "CCDSensitivity",
64 => "Normal",
125 => "+1.0",
250 => "+2.0",
244 => "+3.0",
80 => "Normal",
100 => "High",
},
);
my %makernotes = (
"NIKON E700" => [8, 'CoolPix', \%nikon1_tags],
"NIKON E800" => [8, 'CoolPix', \%nikon1_tags],
"NIKON E900" => [8, 'CoolPix', \%nikon1_tags],
"NIKON E900S" => [8, 'CoolPix', \%nikon1_tags],
"NIKON E910" => [8, 'CoolPix', \%nikon1_tags],
"NIKON E950" => [8, 'CoolPix', \%nikon1_tags],
"NIKON E880" => [0, 'CoolPix', \%nikon2_tags],
"NIKON E990" => [0, 'CoolPix', \%nikon2_tags],
"NIKON E995" => [0, 'CoolPix', \%nikon2_tags],
"NIKON CORPORATION NIKON D1" => [0, 'NikonD1', \%nikon2_tags],
"OLYMPUS OPTICAL CO.,LTD C2000Z" => [8, 'Olympus', \%olympus_tags],
"OLYMPUS OPTICAL CO.,LTD C2100UZ" => [8, 'Olympus', \%olympus_tags],
"OLYMPUS OPTICAL CO.,LTD C2500L" => [8, 'Olympus', \%olympus_tags],
"OLYMPUS OPTICAL CO.,LTD C3030Z" => [8, 'Olympus', \%olympus_tags],
"OLYMPUS OPTICAL CO.,LTD C3040Z" => [8, 'Olympus', \%olympus_tags],
"OLYMPUS OPTICAL CO.,LTD C4100Z,C4000Z" => [8, 'Olympus', \%olympus_tags],
"OLYMPUS OPTICAL CO.,LTD E-10" => [8, 'Olympus', \%olympus_tags],
"FUJIFILM FinePix4900ZOOM" => [-1, 'FinePix', \%fujifilm_tags],
"FUJIFILM FinePix6900ZOOM" => [-1, 'FinePix', \%fujifilm_tags],
"FUJIFILM FinePix40i" => [-1, 'FinePix', \%fujifilm_tags],
"FUJIFILM FinePix4700 ZOOM" => [-1, 'FinePix', \%fujifilm_tags],
"FUJIFILM FinePixS1Pro" => [-1, 'FinePix', \%fujifilm_tags],
"CASIO QV-3000EX" => [0, 'Casio', \%casio_tags],
"Canon Canon EOS D30" => [0, 'Canon', {}],
"Canon Canon EOS D60" => [0, 'Canon', {}],
"Canon Canon DIGITAL IXUS" => [0, 'Canon', {}],
"Canon Canon DIGITAL IXUS 300" => [0, 'Canon', {}],
"Canon Canon PowerShot G1" => [0, 'Canon', {}],
"Canon Canon PowerShot Pro90 IS" => [0, 'Canon', {}],
"Canon Canon PowerShot S10" => [0, 'Canon', {}],
"Canon Canon PowerShot S20" => [0, 'Canon', {}],
);
my %exif_intr_tags = (
0x1 => "InteroperabilityIndex",
0x2 => "InteroperabilityVersion",
0x1000 => "RelatedImageFileFormat",
0x1001 => "RelatedImageWidth",
0x1002 => "RelatedImageLength",
);
# Tag decode helpers
sub components_configuration_decoder;
sub file_source_decoder;
sub scene_type_decoder;
my %exif_tags = (
0x828D => "CFARepeatPatternDim",
0x828E => "CFAPattern",
0x828F => "BatteryLevel",
0x8298 => "Copyright",
0x829A => "ExposureTime",
0x829D => "FNumber",
0x83BB => "IPTC/NAA",
0x8769 => "ExifOffset",
0x8773 => "InterColorProfile",
0x8822 => { __TAG__ => "ExposureProgram",
0 => "unknown",
1 => "Manual",
2 => "Program",
3 => "Aperture priority",
4 => "Shutter priority",
5 => "Program creative",
6 => "Program action",
7 => "Portrait",
8 => "Landscape",
# 9 .. 255 reserved
},
0x8824 => "SpectralSensitivity",
0x8825 => "GPSInfo",
0x8827 => "ISOSpeedRatings",
0x8828 => "OECF",
0x9000 => "ExifVersion",
0x9003 => "DateTimeOriginal",
0x9004 => "DateTimeDigitized",
0x9101 => { __TAG__ => "ComponentsConfiguration",
DECODER => \&components_configuration_decoder,
},
0x9102 => "CompressedBitsPerPixel",
0x9201 => "ShutterSpeedValue",
0x9202 => "ApertureValue",
0x9203 => "BrightnessValue",
0x9204 => "ExposureBiasValue",
0x9205 => "MaxApertureValue",
0x9206 => "SubjectDistance",
0x9207 => { __TAG__ => "MeteringMode",
0 => "unknown",
1 => "Average",
2 => "CenterWeightedAverage",
3 => "Spot",
4 => "MultiSpot",
5 => "Pattern",
6 => "Partial",
# 7 .. 254 reserved in EXIF 1.2
255 => "other",
},
0x9208 => { __TAG__ => "LightSource",
0 => "unknown",
1 => "Daylight",
2 => "Fluorescent",
3 => "Tungsten",
4 => "Flash",
# 5 .. 8 reserveed in EXIF 2.2
9 => "Fine weather",
10 => "Cloudy weather",
11 => "Shade",
12 => "Daylight fluorescent (D 5700-7100K)",
13 => "Day white fluorescent (N 4600-5400K)",
14 => "Cool white fluorescent (W 3900-4500K)",
15 => "White fluorescent (WW 3200-3700K)",
17 => "Standard light A",
18 => "Standard light B",
19 => "Standard light C",
20 => "D55",
21 => "D65",
22 => "D75",
23 => "D50",
24 => "ISO studio tungesten",
# 25 .. 254 reserved in EXIF 2.2
255 => "other light source",
},
0x9209 => { __TAG__ => "Flash",
0x0000 => "Flash did not fire",
0x0001 => "Flash fired",
0x0005 => "Strobe return light not detected",
0x0007 => "Strobe return light detected",
0x0009 => "Flash fired, compulsory flash mode",
0x000D => "Flash fired, compulsory flash mode, return light not detected",
0x000F => "Flash fired, compulsory flash mode, return light detected",
0x0010 => "Flash did not fire, compulsory flash mode",
0x0018 => "Flash did not fire, auto mode",
0x0019 => "Flash fired, auto mode",
0x001D => "Flash fired, auto mode, return light not detected",
0x001F => "Flash fired, auto mode, return light detected",
0x0020 => "No flash function",
0x0041 => "Flash fired, red-eye reduction mode",
0x0045 => "Flash fired, red-eye reduction mode, return light not detected",
0x0047 => "Flash fired, red-eye reduction mode, return light detected",
0x0049 => "Flash fired, compulsory flash mode, red-eye reduction mode",
0x004D => "Flash fired, compulsory flash mode, red-eye reduction mode, return light not detected",
0x004F => "Flash fired, compulsory flash mode, red-eye reduction mode, return light detected",
0x0059 => "Flash fired, auto mode, red-eye reduction mode",
0x005D => "Flash fired, auto mode, return light not detected, red-eye reduction mode",
0x005F => "Flash fired, auto mode, return light detected, red-eye reduction mode"
},
0x920A => "FocalLength",
0x9214 => "SubjectArea",
0x927C => "MakerNote",
0x9286 => "UserComment",
0x9290 => "SubSecTime",
0x9291 => "SubSecTimeOriginal",
0x9292 => "SubSecTimeDigitized",
0xA000 => "FlashPixVersion",
0xA001 => "ColorSpace",
0xA002 => "ExifImageWidth",
0xA003 => "ExifImageLength",
0xA004 => "RelatedAudioFile",
0xA005 => {__TAG__ => "InteroperabilityOffset",
__SUBIFD__ => \%exif_intr_tags,
},
0xA20B => "FlashEnergy", # 0x920B in TIFF/EP
0xA20C => "SpatialFrequencyResponse", # 0x920C - -
0xA20E => "FocalPlaneXResolution", # 0x920E - -
0xA20F => "FocalPlaneYResolution", # 0x920F - -
0xA210 => { __TAG__ => "FocalPlaneResolutionUnit", # 0x9210 - -
1 => "dpi",
2 => "dpm",
3 => "dpcm",
4 => "dpmm",
5 => "dp?",
},
0xA214 => "SubjectLocation", # 0x9214 - -
0xA215 => "ExposureIndex", # 0x9215 - -
0xA217 => {__TAG__ => "SensingMethod",
1 => "Not defined",
2 => "One-chip color area sensor",
3 => "Two-chip color area sensor",
4 => "Three-chip color area sensor",
5 => "Color sequential area sensor",
7 => "Trilinear sensor",
8 => "Color sequential linear sensor"
},
0xA300 => {__TAG__ => "FileSource",
DECODER => \&file_source_decoder,
},
0xA301 => {__TAG__ => "SceneType",
DECODER => \&scene_type_decoder,
},
0xA302 => "CFAPattern",
0xA401 => {__TAG__ => "CustomRendered",
0 => "Normal process",
1 => "Custom process"
},
0xA402 => {__TAG__ => "ExposureMode",
0 => "Auto exposure",
1 => "Manual exposure",
2 => "Auto bracket"
},
0xA403 => {__TAG__ => "WhiteBalance",
0 => "Auto white balance",
1 => "Manual white balance"
},
0xA404 => "DigitalZoomRatio",
0xA405 => "FocalLengthIn35mmFilm",
0xA406 => {__TAG__ => "SceneCaptureType",
0 => "Standard",
1 => "Landscape",
2 => "Portrait",
3 => "Night Scene"
},
0xA407 => {__TAG__ => "GainControl",
0 => "None",
1 => "Low gain up",
2 => "High gain up",
3 => "Low gain down",
4 => "High gain down"
},
0xA408 => {__TAG__ => "Contrast",
0 => "Normal",
1 => "Soft",
2 => "Hard"
},
0xA409 => {__TAG__ => "Saturation",
0 => "Normal",
1 => "Low saturation",
2 => "High saturation"
},
0xA40A => {__TAG__ => "Sharpness",
0 => "Normal",
1 => "Soft",
2 => "Hard"
},
0xA40B => "DeviceSettingDescription",
0xA40C => {__TAG__ => "SubjectDistanceRange",
0 => "Unknown",
1 => "Macro",
2 => "Close view",
3 => "Distant view"
},
0xA420 => "ImageUniqueID",
);
my %tiff_tags = (
254 => { __TAG__ => "NewSubfileType",
1 => "ReducedResolution",
2 => "SinglePage",
4 => "TransparencyMask",
},
255 => { __TAG__ => "SubfileType",
1 => "FullResolution",
2 => "ReducedResolution",
3 => "SinglePage",
},
256 => "width",
257 => "height",
258 => "BitsPerSample",
259 => { __TAG__ => "Compression",
1 => "PackBytes",
2 => "CCITT Group3",
3 => "CCITT T4",
4 => "CCITT T6",
5 => "LZW",
6 => "JPEG",
32773 => "PackBits",
},
262 => { __TAG__ => "PhotometricInterpretation",
0 => "WhiteIsZero",
1 => "BlackIsZero",
2 => "RGB",
3 => "RGB Palette",
4 => "Transparency Mask",
5 => "CMYK",
6 => "YCbCr",
8 => "CIELab",
},
263 => { __TAG__ => "Threshholding",
1 => "NoDithering",
2 => "OrderedDither",
3 => "Randomized",
},
266 => { __TAG__ => "FillOrder",
1 => "LowInHigh",
2 => "HighInLow",
},
270 => "ImageDescription",
271 => "Make",
272 => "Model",
273 => "StripOffsets",
274 => { __TAG__ => "Orientation",
1 => "top_left",
2 => "top_right",
3 => "bot_right",
4 => "bot_left",
5 => "left_top",
6 => "right_top",
7 => "right_bot",
8 => "left_bot",
},
277 => "SamplesPerPixel",
278 => "RowsPerStrip",
279 => "StripByteCounts",
282 => "XResolution",
283 => "YResolution",
284 => {__TAG__ => "PlanarConfiguration",
1 => "Chunky", 2 => "Planar",
},
296 => {__TAG__ => "ResolutionUnit",
1 => "pixels", 2 => "dpi", 3 => "dpcm",
},
297 => "PageNumber",
301 => "TransferFunction",
305 => "Software",
306 => "DateTime",
315 => "Artist",
318 => "WhitePoint",
319 => "PrimaryChromaticities",
320 => "ColorMap",
513 => "JPEGInterchangeFormat",
514 => "JPEGInterchangeFormatLngth",
529 => "YCbCrCoefficients",
530 => "YCbCrSubSampling",
531 => "YCbCrPositioning",
532 => "ReferenceBlackWhite",
33432 => "Copyright",
34665 => { __TAG__ => "ExifOffset",
__SUBIFD__ => \%exif_tags,
},
);
sub new
{
my $class = shift;
my $source = shift;
if (!ref($source)) {
local(*F);
open(F, $source) || return;
binmode(F);
$source = \*F;
}
if (ref($source) ne "SCALAR") {
# XXX should really only read the file on demand
local($/); # slurp mode
my $data = <$source>;
$source = \$data;
}
my $self = bless { source => $source }, $class;
for ($$source) {
my $byte_order = substr($_, 0, 2);
$self->{little_endian} = ($byte_order eq "II");
$self->{version} = $self->unpack("n", substr($_, 2, 2));
my $ifd = $self->unpack("N", substr($_, 4, 4));
while ($ifd) {
push(@{$self->{ifd}}, $ifd);
my($num_fields) = $self->unpack("x$ifd n", $_);
$ifd = $self->unpack("N", substr($_, $ifd + 2 + $num_fields*12, 4));
}
}
$self;
}
sub unpack
{
my $self = shift;
my $template = shift;
if ($self->{little_endian}) {
$template =~ tr/nN/vV/;
}
#print "UNPACK $template\n";
CORE::unpack($template, $_[0]);
}
sub num_ifds
{
my $self = shift;
scalar @{$self->{ifd}};
}
sub ifd
{
my $self = shift;
my $num = shift || 0;
my @ifd;
return $self->add_fields($self->{ifd}[$num], \@ifd);
}
sub tagname
{
$tiff_tags{$_[1]} || sprintf "Tag-0x%04x",$_[1];
}
sub exif_tagname
{
$tiff_tags{$_[1]} || $exif_tags{$_[1]} || sprintf "Tag-0x%04x",$_[1];
}
sub add_fields
{
my($self, $offset, $ifds, $tags, $voff_plus) = @_;
return unless $offset;
$tags ||= \%tiff_tags;
for (${$self->{source}}) { # alias as $_
last if $offset > length($_) - 2; # bad offset
my $entries = $self->unpack("x$offset n", $_);
my $max_entries = int((length($_) - $offset - 2) / 12);
#print "ENTRIES $entries $max_entries\n";
if ($entries > $max_entries) {
# Hmmm, something smells bad here... parsing garbage
$entries = $max_entries;
last;
}
FIELD:
for my $i (0 .. $entries-1) {
my $entry_offset = 2 + $offset + $i*12;
my($tag, $type, $count, $voff) =
$self->unpack("nnNN", substr($_, $entry_offset, 12));
#print "TAG $tag $type $count $voff\n";
if ($type == 0 || $type > @types) {
# unknown type code might indicate that we are parsing garbage
next;
}
# extract type information
my($tmpl, $vlen);
($type, $tmpl, $vlen) = @{$types[$type-1]};
die "Assert" unless $type;
if ($count * $vlen <= 4) {
$voff = $entry_offset + 8;
}
elsif ($voff + $count * $vlen > length($_)) {
# offset points outside of string, corrupt entry ignore
next;
}
else {
$voff += $voff_plus || 0;
}
$tmpl =~ s/(\d+)$/$count*$1/e;
my @v = $self->unpack("x$voff $tmpl", $_);
if ($type =~ /^S(SHORT|LONG|RATIONAL)/) {
my $max = 2 ** ($1 eq "SHORT" ? 15 : 31);
$v[0] -= ($max * 2) if $v[0] >= $max;
}
my $val = (@v > 1) ? \@v : $v[0];
bless $val, "Image::TIFF::Rational" if $type =~ /^S?RATIONAL$/;
$tag = $tags->{$tag} || $self->tagname($tag);
if ($tag eq 'MakerNote' && exists $makernotes{$self->{Make}.' '.$self->{Model}}) {
my ($ifd_off, $tag_prefix, $sub) = @{$makernotes{$self->{Make}.' '.$self->{Model}}};
$self->{tag_prefix} = $tag_prefix;
if ($ifd_off < 0) {
# fuji kludge - http://www.butaman.ne.jp/~tsuruzoh/Computer/Digicams/exif-e.html#APP4
my $save_endian = $self->{little_endian};
$self->{little_endian} = 1;
$ifd_off = $self->unpack("N", substr($val, 8, 4));
$self->add_fields($voff+$ifd_off, $ifds, $sub, $voff);
$self->{little_endian} = $save_endian;
} else {
$self->add_fields($voff+$ifd_off, $ifds, $sub);
}
delete $self->{tag_prefix};
next FIELD;
}
if (ref($tag)) {
die "Assert" unless ref($tag) eq "HASH";
if (my $sub = $tag->{__SUBIFD__}) {
next if $val < 0 || $val > length($_);
#print "SUBIFD $tag->{__TAG__} $val ", length($_), "\n";
$self->add_fields($val, $ifds, $sub);
next FIELD;
}
#hack for UNDEFINED values, they all have different
#meanings depending on tag
$val = &{$tag->{DECODER}}($self,$val) if defined($tag->{DECODER});
$val = $tag->{$val} if exists $tag->{$val};
$tag = $tag->{__TAG__};
}
$tag = $self->{tag_prefix} . '-' . $tag if $self->{tag_prefix};
$self->_push_field($ifds, $tag, $type, $count, $val);
$self->{$tag} = $val if ($tag eq 'Make' or $tag eq 'Model');
}
}
$ifds;
}
sub _push_field
{
my $self = shift;
my $ifds = shift;
push(@$ifds, [@_]);
}
sub components_configuration_decoder
{
my $self = shift;
my $val = shift;
my $rv = "";
my %v = (
0 => undef,
1 => 'Y',
2 => 'Cb',
3 => 'Cr',
4 => 'R',
5 => 'G',
6 => 'B',
);
return join ( '', map { $v{$_} if defined($v{$_}) } $self->unpack('c4',$val) );
}
sub file_source_decoder
{
my $self = shift;
my $val = shift;
my %v = (
3 => "(DSC) Digital Still Camera",
);
$val = $self->unpack('c',$val);
return $v{$val} if $v{$val};
return "Other";
}
sub scene_type_decoder
{
my $self = shift;
my $val = shift;
my %v = (
1 => "Directly Photographed Image",
);
$val = $self->unpack('c',$val);
return $v{$val} if $v{$val};
return "Other";
}
package Image::TIFF::Rational;
use overload '""' => \&as_string,
'0+' => \&as_float,
fallback => 1;
sub new {
my($class, $a, $b) = @_;
bless [$a, $b], $class;
}
sub as_string {
my $self = shift;
#warn "@$self";
"$self->[0]/$self->[1]";
}
sub as_float {
my $self = shift;
# We check here because some stupid cameras (Samsung Digimax 200)
# use rationals with 0 denominator (found in thumbnail resolution spec).
if ($self->[1]) {
return $self->[0] / $self->[1];
}
else {
return $self->[0];
}
}
1;