#------------------------------------------------------------------------------
# File: BMP.pm
#
# Description: Read BMP meta information
#
# Revisions: 07/16/2005 - P. Harvey Created
#
# References: 1) http://www.fortunecity.com/skyscraper/windows/364/bmpffrmt.html
# 2) http://www.fourcc.org/rgb.php
# 3) https://msdn.microsoft.com/en-us/library/dd183381(v=vs.85).aspx
#------------------------------------------------------------------------------
package Image::ExifTool::BMP;
use strict;
use vars qw($VERSION);
use Image::ExifTool qw(:DataAccess :Utils);
$VERSION = '1.09';
# conversions for fixed-point 2.30 format values
my %fixed2_30 = (
ValueConv => q{
my @a = split ' ', $val;
$_ /= 0x40000000 foreach @a;
"@a";
},
PrintConv => q{
my @a = split ' ', $val;
$_ = sprintf('%.6f', $_) foreach @a;
"@a";
},
);
# BMP chunks
%Image::ExifTool::BMP::Main = (
PROCESS_PROC => \&Image::ExifTool::ProcessBinaryData,
GROUPS => { 0 => 'File', 1 => 'File', 2 => 'Image' },
NOTES => q{
There really isn't much meta information in a BMP file as such, just a bit
of image related information.
},
0 => {
Name => 'BMPVersion',
Format => 'int32u',
Notes => q{
this is actually the size of the BMP header, but used to determine the BMP
version
},
RawConv => '$$self{BMPVersion} = $val',
PrintConv => {
40 => 'Windows V3',
68 => 'AVI BMP structure?', #PH (seen in AVI movies from some Casio and Nikon cameras)
108 => 'Windows V4',
124 => 'Windows V5',
},
},
4 => {
Name => 'ImageWidth',
Format => 'int32u',
},
8 => {
Name => 'ImageHeight',
Format => 'int32s', # (negative when stored in top-to-bottom order)
ValueConv => 'abs($val)',
},
12 => {
Name => 'Planes',
Format => 'int16u',
# values: 0,1,4,8,16,24,32
},
14 => {
Name => 'BitDepth',
Format => 'int16u',
},
16 => {
Name => 'Compression',
Format => 'int32u',
RawConv => '$$self{BMPCompression} = $val',
# (formatted as string[4] for some values in AVI images)
ValueConv => '$val > 256 ? unpack("A4",pack("V",$val)) : $val',
PrintConv => {
0 => 'None',
1 => '8-Bit RLE',
2 => '4-Bit RLE',
3 => 'Bitfields',
4 => 'JPEG', #2
5 => 'PNG', #2
# pass through ASCII video compression codec ID's
OTHER => sub {
my $val = shift;
# convert non-ascii characters
$val =~ s/([\0-\x1f\x7f-\xff])/sprintf('\\x%.2x',ord $1)/eg;
return $val;
},
},
},
20 => {
Name => 'ImageLength',
Format => 'int32u',
RawConv => '$$self{BMPImageLength} = $val',
},
24 => {
Name => 'PixelsPerMeterX',
Format => 'int32u',
},
28 => {
Name => 'PixelsPerMeterY',
Format => 'int32u',
},
32 => {
Name => 'NumColors',
Format => 'int32u',
PrintConv => '$val ? $val : "Use BitDepth"',
},
36 => {
Name => 'NumImportantColors',
Format => 'int32u',
Hook => '$varSize += $size if $$self{BMPVersion} == 68', # (the rest is invalid for AVI BMP's)
PrintConv => '$val ? $val : "All"',
},
40 => {
Name => 'RedMask',
Format => 'int32u',
PrintConv => 'sprintf("0x%.8x",$val)',
},
44 => {
Name => 'GreenMask',
Format => 'int32u',
PrintConv => 'sprintf("0x%.8x",$val)',
},
48 => {
Name => 'BlueMask',
Format => 'int32u',
PrintConv => 'sprintf("0x%.8x",$val)',
},
52 => {
Name => 'AlphaMask',
Format => 'int32u',
PrintConv => 'sprintf("0x%.8x",$val)',
},
56 => {
Name => 'ColorSpace',
Format => 'undef[4]',
RawConv => '$$self{BMPColorSpace} = $val =~ /\0/ ? Get32u(\$val, 0) : pack("N",unpack("V",$val))',
PrintConv => {
0 => 'Calibrated RGB',
1 => 'Device RGB',
2 => 'Device CMYK',
LINK => 'Linked Color Profile',
MBED => 'Embedded Color Profile',
sRGB => 'sRGB',
'Win ' => 'Windows Color Space',
},
},
60 => {
Name => 'RedEndpoint',
Condition => '$$self{BMPColorSpace} eq "0"',
Format => 'int32u[3]',
%fixed2_30,
},
72 => {
Name => 'GreenEndpoint',
Condition => '$$self{BMPColorSpace} eq "0"',
Format => 'int32u[3]',
%fixed2_30,
},
84 => {
Name => 'BlueEndpoint',
Condition => '$$self{BMPColorSpace} eq "0"',
Format => 'int32u[3]',
%fixed2_30,
},
96 => {
Name => 'GammaRed',
Condition => '$$self{BMPColorSpace} eq "0"',
Format => 'fixed32u',
},
100 => {
Name => 'GammaGreen',
Condition => '$$self{BMPColorSpace} eq "0"',
Format => 'fixed32u',
},
104 => {
Name => 'GammaBlue',
Condition => '$$self{BMPColorSpace} eq "0"',
Format => 'fixed32u',
},
108 => {
Name => 'RenderingIntent',
Format => 'int32u',
PrintConv => {
1 => 'Graphic (LCS_GM_BUSINESS)',
2 => 'Proof (LCS_GM_GRAPHICS)',
4 => 'Picture (LCS_GM_IMAGES)',
8 => 'Absolute Colorimetric (LCS_GM_ABS_COLORIMETRIC)',
},
},
112 => {
Name => 'ProfileDataOffset',
Condition => '$$self{BMPColorSpace} eq "LINK" or $$self{BMPColorSpace} eq "MBED"',
Format => 'int32u',
RawConv => '$$self{BMPProfileOffset} = $val',
},
116 => {
Name => 'ProfileSize',
Condition => '$$self{BMPColorSpace} eq "LINK" or $$self{BMPColorSpace} eq "MBED"',
Format => 'int32u',
RawConv => '$$self{BMPProfileSize} = $val',
},
# 120 - reserved
);
# OS/2 12-byte bitmap header (ref http://www.fileformat.info/format/bmp/egff.htm)
%Image::ExifTool::BMP::OS2 = (
PROCESS_PROC => \&Image::ExifTool::ProcessBinaryData,
GROUPS => { 0 => 'File', 1 => 'File', 2 => 'Image' },
NOTES => 'Information extracted from OS/2-format BMP images.',
0 => {
Name => 'BMPVersion',
Format => 'int32u',
Notes => 'again, the header size is used to determine the BMP version',
PrintConv => {
12 => 'OS/2 V1',
64 => 'OS/2 V2',
},
},
4 => { Name => 'ImageWidth', Format => 'int16u' },
6 => { Name => 'ImageHeight', Format => 'int16u' },
8 => { Name => 'Planes', Format => 'int16u' },
10 => { Name => 'BitDepth', Format => 'int16u' },
);
%Image::ExifTool::BMP::Extra = (
GROUPS => { 0 => 'File', 1 => 'File', 2 => 'Image' },
NOTES => 'Extra information extracted from some BMP images.',
VARS => { NO_ID => 1 },
LinkedProfileName => { },
ICC_Profile => { SubDirectory => { TagTable => 'Image::ExifTool::ICC_Profile::Main' } },
EmbeddedJPG => {
Groups => { 2 => 'Preview' },
Binary => 1,
},
EmbeddedPNG => {
Groups => { 2 => 'Preview' },
Binary => 1,
},
);
#------------------------------------------------------------------------------
# Extract EXIF information from a BMP image
# Inputs: 0) ExifTool object reference, 1) dirInfo reference
# Returns: 1 on success, 0 if this wasn't a valid BMP file
sub ProcessBMP($$)
{
my ($et, $dirInfo) = @_;
my $raf = $$dirInfo{RAF};
my ($buff, $tagTablePtr);
# verify this is a valid BMP file
return 0 unless $raf->Read($buff, 18) == 18;
return 0 unless $buff =~ /^BM/;
SetByteOrder('II');
my $len = Get32u(\$buff, 14);
# len = v1:12, v4:108, v5:124
return 0 unless $len == 12 or $len == 16 or ($len >= 40 and $len < 1000000);
return 0 unless $raf->Seek(-4, 1) and $raf->Read($buff, $len) == $len;
$et->SetFileType(); # set the FileType tag
#
# process the BMP header
#
my %dirInfo = (
DataPt => \$buff,
DirStart => 0,
DirLen => length($buff),
);
if ($len == 12 or $len == 16 or $len == 64) { # old OS/2 format BMP
$tagTablePtr = GetTagTable('Image::ExifTool::BMP::OS2');
} else {
$tagTablePtr = GetTagTable('Image::ExifTool::BMP::Main');
}
$et->ProcessDirectory(\%dirInfo, $tagTablePtr);
#
# extract any embedded images
#
my $extraTable = GetTagTable('Image::ExifTool::BMP::Extra');
if ($$et{BMPCompression} and $$et{BMPImageLength} and
($$et{BMPCompression} == 4 or $$et{BMPCompression} == 5))
{
my $tag = $$et{BMPCompression} == 4 ? 'EmbeddedJPG' : 'EmbeddedPNG';
my $val = $et->ExtractBinary($raf->Tell(), $$et{BMPImageLength}, $tag);
if ($val) {
$et->HandleTag($extraTable, $tag, $val);
}
}
#
# process profile data if it exists (v5 header only)
#
if ($len == 124 and $$et{BMPProfileOffset}) {
my $pos = $$et{BMPProfileOffset} + 14; # (note the 14-byte shift!)
my $size = $$et{BMPProfileSize};
if ($raf->Seek($pos, 0) and $raf->Read($buff, $size) == $size) {
my $tag;
if ($$et{BMPColorSpace} eq 'LINK') {
$buff =~ s/\0+$//; # remove null terminator(s)
$buff = $et->Decode($buff, 'Latin'); # convert from Latin
$tag = 'LinkedProfileName';
} else {
$tag = 'ICC_Profile';
}
$et->HandleTag($extraTable, $tag => $buff, Size => $size, DataPos => $pos);
} else {
$et->Warn('Error loading profile data', 1);
}
}
return 1;
}
1; # end
__END__
=head1 NAME
Image::ExifTool::BMP - Read BMP meta information
=head1 SYNOPSIS
This module is used by Image::ExifTool
=head1 DESCRIPTION
This module contains definitions required by Image::ExifTool to read BMP
(Windows Bitmap) images.
=head1 AUTHOR
Copyright 2003-2018, Phil Harvey (phil at owl.phy.queensu.ca)
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
=head1 REFERENCES
=over 4
=item L<http://www.fortunecity.com/skyscraper/windows/364/bmpffrmt.html>
=item L<http://www.fourcc.org/rgb.php>
=item L<https://msdn.microsoft.com/en-us/library/dd183381(v=vs.85).aspx>
=back
=head1 SEE ALSO
L<Image::ExifTool::TagNames/BMP Tags>,
L<Image::ExifTool(3pm)|Image::ExifTool>
=cut