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package Data::ParseBinary::Graphics::PNG;
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1
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1261
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use strict;
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1
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1
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33
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use warnings;
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28
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4
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4
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use Data::ParseBinary;
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1
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1
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1
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374
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5
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1
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1
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7
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use Data::ParseBinary qw{GreedyRange};
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1
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2
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1
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1821
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6
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7
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# Portable Network Graphics (PNG) file format
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8
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# Official spec: http://www.w3.org/TR/PNG
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9
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#
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10
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# Original code contributed by Robin Munn (rmunn at pobox dot com)
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11
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# (although the code has been extensively reorganized to meet Construct's
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12
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# coding conventions)
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13
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14
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15
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#===============================================================================
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16
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# utils
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17
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#===============================================================================
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18
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sub Coord {
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19
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4
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4
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0
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6
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my ($name, $field) = @_;
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20
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4
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50
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9
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$field ||= \&UBInt8;
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21
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4
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9
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return Struct($name,
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22
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&$field("x"),
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23
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&$field("y"),
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24
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);
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25
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}
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26
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27
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my $compression_method = Enum(UBInt8("compression_method"),
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28
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deflate => 0,
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29
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_default_ => $DefaultPass
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30
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);
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31
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32
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33
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#===============================================================================
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34
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# 11.2.3: PLTE - Palette
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35
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#===============================================================================
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36
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my $plte_info = Struct("plte_info",
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37
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Value("num_entries", sub { $_->ctx(1)->{length} / 3}),
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38
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Array(sub { $_->ctx->{num_entries} },
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39
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Struct("palette_entries",
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40
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UBInt8("red"),
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41
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UBInt8("green"),
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42
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UBInt8("blue"),
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43
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),
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44
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),
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45
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);
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46
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47
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#===============================================================================
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48
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# 11.2.4: IDAT - Image data
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49
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#===============================================================================
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50
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#my $idat_info = OnDemand(
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51
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# Field("idat_info", sub { $_->ctx->{length} }),
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52
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#);
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53
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my $idat_info = Field("idat_info", sub { $_->ctx->{length} });
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54
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55
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#===============================================================================
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56
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# 11.3.2.1: tRNS - Transparency
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57
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#===============================================================================
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58
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my $trns_info = Switch("trns_info", sub { $_->ctx(1)->{image_header}->{color_type} },
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59
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{
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60
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"greyscale" => Struct("data",
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61
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UBInt16("grey_sample")
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62
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),
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63
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"truecolor" => Struct("data",
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64
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UBInt16("red_sample"),
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65
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UBInt16("blue_sample"),
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66
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UBInt16("green_sample"),
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67
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),
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68
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"indexed" => Array(sub { $_->ctx->{length} },
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69
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UBInt8("alpha"),
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70
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),
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71
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}
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72
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);
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73
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74
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#===============================================================================
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75
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# 11.3.3.1: cHRM - Primary chromacities and white point
|
76
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#===============================================================================
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77
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my $chrm_info = Struct("chrm_info",
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78
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Coord("white_point", \&UBInt32),
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79
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Coord("red", \&UBInt32),
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80
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Coord("green", \&UBInt32),
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81
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Coord("blue", \&UBInt32),
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82
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);
|
83
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84
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#===============================================================================
|
85
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# 11.3.3.2: gAMA - Image gamma
|
86
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#===============================================================================
|
87
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my $gama_info = Struct("gama_info",
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88
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UBInt32("gamma"),
|
89
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);
|
90
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91
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#===============================================================================
|
92
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# 11.3.3.3: iCCP - Embedded ICC profile
|
93
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#===============================================================================
|
94
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my $iccp_info = Struct("iccp_info",
|
95
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CString("name"),
|
96
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$compression_method,
|
97
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Field("compressed_profile",
|
98
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sub { $_->ctx(1)->{length} - (length( $_->ctx->{name}) + 2) }
|
99
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),
|
100
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);
|
101
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102
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#===============================================================================
|
103
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# 11.3.3.4: sBIT - Significant bits
|
104
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#===============================================================================
|
105
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my $sbit_info = Switch("sbit_info", sub { $_->ctx(1)->{image_header}->{color_type} },
|
106
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{
|
107
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"greyscale" => Struct("data",
|
108
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|
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|
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UBInt8("significant_grey_bits"),
|
109
|
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|
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),
|
110
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"truecolor" => Struct("data",
|
111
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UBInt8("significant_red_bits"),
|
112
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UBInt8("significant_green_bits"),
|
113
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UBInt8("significant_blue_bits"),
|
114
|
|
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|
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),
|
115
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"indexed" => Struct("data",
|
116
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UBInt8("significant_red_bits"),
|
117
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UBInt8("significant_green_bits"),
|
118
|
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UBInt8("significant_blue_bits"),
|
119
|
|
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|
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),
|
120
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"greywithalpha" => Struct("data",
|
121
|
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UBInt8("significant_grey_bits"),
|
122
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UBInt8("significant_alpha_bits"),
|
123
|
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),
|
124
|
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"truewithalpha" => Struct("data",
|
125
|
|
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UBInt8("significant_red_bits"),
|
126
|
|
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UBInt8("significant_green_bits"),
|
127
|
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UBInt8("significant_blue_bits"),
|
128
|
|
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|
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UBInt8("significant_alpha_bits"),
|
129
|
|
|
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|
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),
|
130
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|
}
|
131
|
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);
|
132
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|
133
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|
#===============================================================================
|
134
|
|
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|
|
# 11.3.3.5: sRGB - Standard RPG color space
|
135
|
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#===============================================================================
|
136
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my $srgb_info = Struct("srgb_info",
|
137
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Enum(UBInt8("rendering_intent"),
|
138
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perceptual => 0,
|
139
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relative_colorimetric => 1,
|
140
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saturation => 2,
|
141
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absolute_colorimetric => 3,
|
142
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_default_ => $DefaultPass,
|
143
|
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|
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),
|
144
|
|
|
|
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|
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);
|
145
|
|
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|
146
|
|
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#===============================================================================
|
147
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# 11.3.4.3: tEXt - Textual data
|
148
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#===============================================================================
|
149
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my $text_info = Struct("text_info",
|
150
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CString("keyword"),
|
151
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Field("text", sub { $_->ctx(1)->{length} - (length($_->ctx->{keyword}) + 1) }),
|
152
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);
|
153
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|
154
|
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#===============================================================================
|
155
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# 11.3.4.4: zTXt - Compressed textual data
|
156
|
|
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|
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#===============================================================================
|
157
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|
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my $ztxt_info = Struct("ztxt_info",
|
158
|
|
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CString("keyword"),
|
159
|
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$compression_method,
|
160
|
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# OnDemand(
|
161
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Field("compressed_text",
|
162
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# As with iCCP, length is chunk length, minus length of
|
163
|
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|
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# keyword, minus two: one byte for the null terminator,
|
164
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|
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# and one byte for the compression method.
|
165
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|
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sub { $_->ctx(1)->{length} - (length($_->ctx->{keyword}) + 2) },
|
166
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|
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),
|
167
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# ),
|
168
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|
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|
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);
|
169
|
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|
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|
170
|
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|
#===============================================================================
|
171
|
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|
|
# 11.3.4.5: iTXt - International textual data
|
172
|
|
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|
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|
#===============================================================================
|
173
|
|
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|
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|
|
my $itxt_info = Struct("itxt_info",
|
174
|
|
|
|
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|
|
CString("keyword"),
|
175
|
|
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UBInt8("compression_flag"),
|
176
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$compression_method,
|
177
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CString("language_tag"),
|
178
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CString("translated_keyword"),
|
179
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# OnDemand(
|
180
|
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Field("text",
|
181
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|
|
sub { $_->ctx(1)->{length} - (length($_->ctx->{keyword}) + length($_->ctx->{language_tag}) + length($_->ctx->{translated_keyword}) + 5) },
|
182
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|
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),
|
183
|
|
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# ),
|
184
|
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|
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|
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);
|
185
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|
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|
186
|
|
|
|
|
|
|
#===============================================================================
|
187
|
|
|
|
|
|
|
# 11.3.5.1: bKGD - Background color
|
188
|
|
|
|
|
|
|
#===============================================================================
|
189
|
|
|
|
|
|
|
my $bkgd_info = Switch("bkgd_info", sub { $_->ctx(1)->{image_header}->{color_type} },
|
190
|
|
|
|
|
|
|
{
|
191
|
|
|
|
|
|
|
"greyscale" => Struct("data",
|
192
|
|
|
|
|
|
|
UBInt16("background_greyscale_value"),
|
193
|
|
|
|
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|
|
Alias("grey", "background_greyscale_value"),
|
194
|
|
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|
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|
|
),
|
195
|
|
|
|
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|
|
"greywithalpha" => Struct("data",
|
196
|
|
|
|
|
|
|
UBInt16("background_greyscale_value"),
|
197
|
|
|
|
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|
|
Alias("grey", "background_greyscale_value"),
|
198
|
|
|
|
|
|
|
),
|
199
|
|
|
|
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|
|
"truecolor" => Struct("data",
|
200
|
|
|
|
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|
|
UBInt16("background_red_value"),
|
201
|
|
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|
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|
|
UBInt16("background_green_value"),
|
202
|
|
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|
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|
|
UBInt16("background_blue_value"),
|
203
|
|
|
|
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|
|
Alias("red", "background_red_value"),
|
204
|
|
|
|
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|
|
Alias("green", "background_green_value"),
|
205
|
|
|
|
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|
|
Alias("blue", "background_blue_value"),
|
206
|
|
|
|
|
|
|
),
|
207
|
|
|
|
|
|
|
"truewithalpha" => Struct("data",
|
208
|
|
|
|
|
|
|
UBInt16("background_red_value"),
|
209
|
|
|
|
|
|
|
UBInt16("background_green_value"),
|
210
|
|
|
|
|
|
|
UBInt16("background_blue_value"),
|
211
|
|
|
|
|
|
|
Alias("red", "background_red_value"),
|
212
|
|
|
|
|
|
|
Alias("green", "background_green_value"),
|
213
|
|
|
|
|
|
|
Alias("blue", "background_blue_value"),
|
214
|
|
|
|
|
|
|
),
|
215
|
|
|
|
|
|
|
"indexed" => Struct("data",
|
216
|
|
|
|
|
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|
UBInt16("background_palette_index"),
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Alias("index", "background_palette_index"),
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218
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),
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219
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}
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220
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);
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221
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222
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#===============================================================================
|
223
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# 11.3.5.2: hIST - Image histogram
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224
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#===============================================================================
|
225
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my $hist_info = Array(sub { $_->ctx(1)->{length} / 2 },
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226
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UBInt16("frequency"),
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227
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);
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228
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229
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#===============================================================================
|
230
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# 11.3.5.3: pHYs - Physical pixel dimensions
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#===============================================================================
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232
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my $phys_info = Struct("phys_info",
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UBInt32("pixels_per_unit_x"),
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234
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UBInt32("pixels_per_unit_y"),
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235
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Enum(UBInt8("unit"),
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236
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unknown => 0,
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meter => 1,
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238
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_default_ => $DefaultPass,
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239
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),
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240
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);
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241
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242
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#===============================================================================
|
243
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# 11.3.5.4: sPLT - Suggested palette
|
244
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#===============================================================================
|
245
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sub splt_info_data_length {
|
246
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0
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0
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0
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my $entry_size;
|
247
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0
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0
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if ($_->ctx->{sample_depth} == 8) {
|
248
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0
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$entry_size = 6;
|
249
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} else {
|
250
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0
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$entry_size = 10;
|
251
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}
|
252
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0
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|
return ($_->ctx(1)->{length} - length($_->ctx->{name}) - 2) / $entry_size;
|
253
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}
|
254
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|
255
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my $splt_info = Struct("data",
|
256
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CString("name"),
|
257
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UBInt8("sample_depth"),
|
258
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Array(\&splt_info_data_length,
|
259
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|
|
IfThenElse("table", sub { $_->ctx->{sample_depth} == 8 },
|
260
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|
# Sample depth 8
|
261
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|
Struct("table",
|
262
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UBInt8("red"),
|
263
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|
UBInt8("green"),
|
264
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|
UBInt8("blue"),
|
265
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|
UBInt8("alpha"),
|
266
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|
UBInt16("frequency"),
|
267
|
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),
|
268
|
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|
|
|
# Sample depth 16
|
269
|
|
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|
|
Struct("table",
|
270
|
|
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|
|
UBInt16("red"),
|
271
|
|
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|
UBInt16("green"),
|
272
|
|
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|
UBInt16("blue"),
|
273
|
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|
UBInt16("alpha"),
|
274
|
|
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|
UBInt16("frequency"),
|
275
|
|
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|
|
),
|
276
|
|
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|
|
|
|
),
|
277
|
|
|
|
|
|
|
),
|
278
|
|
|
|
|
|
|
);
|
279
|
|
|
|
|
|
|
|
280
|
|
|
|
|
|
|
#===============================================================================
|
281
|
|
|
|
|
|
|
# 11.3.6.1: tIME - Image last-modification time
|
282
|
|
|
|
|
|
|
#===============================================================================
|
283
|
|
|
|
|
|
|
my $time_info = Struct("data",
|
284
|
|
|
|
|
|
|
UBInt16("year"),
|
285
|
|
|
|
|
|
|
UBInt8("month"),
|
286
|
|
|
|
|
|
|
UBInt8("day"),
|
287
|
|
|
|
|
|
|
UBInt8("hour"),
|
288
|
|
|
|
|
|
|
UBInt8("minute"),
|
289
|
|
|
|
|
|
|
UBInt8("second"),
|
290
|
|
|
|
|
|
|
);
|
291
|
|
|
|
|
|
|
|
292
|
|
|
|
|
|
|
#===============================================================================
|
293
|
|
|
|
|
|
|
# chunks
|
294
|
|
|
|
|
|
|
#===============================================================================
|
295
|
|
|
|
|
|
|
my $default_chunk_info =
|
296
|
|
|
|
|
|
|
# OnDemand(HexDumpAdapter(
|
297
|
|
|
|
|
|
|
Field(undef, sub {$_->ctx->{length} }
|
298
|
|
|
|
|
|
|
# ))
|
299
|
|
|
|
|
|
|
);
|
300
|
|
|
|
|
|
|
|
301
|
|
|
|
|
|
|
my $chunk = Struct("chunk",
|
302
|
|
|
|
|
|
|
UBInt32("length"),
|
303
|
|
|
|
|
|
|
String("type", 4),
|
304
|
|
|
|
|
|
|
Switch("data", sub { $_->ctx->{type} },
|
305
|
|
|
|
|
|
|
{
|
306
|
|
|
|
|
|
|
"PLTE" => $plte_info,
|
307
|
|
|
|
|
|
|
"IEND" => $DefaultPass,
|
308
|
|
|
|
|
|
|
"IDAT" => $idat_info,
|
309
|
|
|
|
|
|
|
"tRNS" => $trns_info,
|
310
|
|
|
|
|
|
|
"cHRM" => $chrm_info,
|
311
|
|
|
|
|
|
|
"gAMA" => $gama_info,
|
312
|
|
|
|
|
|
|
"iCCP" => $iccp_info,
|
313
|
|
|
|
|
|
|
"sBIT" => $sbit_info,
|
314
|
|
|
|
|
|
|
"sRGB" => $srgb_info,
|
315
|
|
|
|
|
|
|
"tEXt" => $text_info,
|
316
|
|
|
|
|
|
|
"zTXt" => $ztxt_info,
|
317
|
|
|
|
|
|
|
"iTXt" => $itxt_info,
|
318
|
|
|
|
|
|
|
"bKGD" => $bkgd_info,
|
319
|
|
|
|
|
|
|
"hIST" => $hist_info,
|
320
|
|
|
|
|
|
|
"pHYs" => $phys_info,
|
321
|
|
|
|
|
|
|
"sPLT" => $splt_info,
|
322
|
|
|
|
|
|
|
"tIME" => $time_info,
|
323
|
|
|
|
|
|
|
},
|
324
|
|
|
|
|
|
|
default => $default_chunk_info,
|
325
|
|
|
|
|
|
|
),
|
326
|
|
|
|
|
|
|
UBInt32("crc"),
|
327
|
|
|
|
|
|
|
);
|
328
|
|
|
|
|
|
|
|
329
|
|
|
|
|
|
|
my $image_header_chunk = Struct("image_header",
|
330
|
|
|
|
|
|
|
UBInt32("length"),
|
331
|
|
|
|
|
|
|
Const(String("type", 4), "IHDR"),
|
332
|
|
|
|
|
|
|
UBInt32("width"),
|
333
|
|
|
|
|
|
|
UBInt32("height"),
|
334
|
|
|
|
|
|
|
UBInt8("bit_depth"),
|
335
|
|
|
|
|
|
|
Enum(UBInt8("color_type"),
|
336
|
|
|
|
|
|
|
greyscale => 0,
|
337
|
|
|
|
|
|
|
truecolor => 2,
|
338
|
|
|
|
|
|
|
indexed => 3,
|
339
|
|
|
|
|
|
|
greywithalpha => 4,
|
340
|
|
|
|
|
|
|
truewithalpha => 6,
|
341
|
|
|
|
|
|
|
_default_ => $DefaultPass,
|
342
|
|
|
|
|
|
|
),
|
343
|
|
|
|
|
|
|
$compression_method,
|
344
|
|
|
|
|
|
|
Enum(UBInt8("filter_method"),
|
345
|
|
|
|
|
|
|
# "adaptive filtering with five basic filter types"
|
346
|
|
|
|
|
|
|
adaptive5 => 0,
|
347
|
|
|
|
|
|
|
_default_ => $DefaultPass,
|
348
|
|
|
|
|
|
|
),
|
349
|
|
|
|
|
|
|
Enum(UBInt8("interlace_method"),
|
350
|
|
|
|
|
|
|
none => 0,
|
351
|
|
|
|
|
|
|
adam7 => 1,
|
352
|
|
|
|
|
|
|
_default_ => $DefaultPass,
|
353
|
|
|
|
|
|
|
),
|
354
|
|
|
|
|
|
|
UBInt32("crc"),
|
355
|
|
|
|
|
|
|
);
|
356
|
|
|
|
|
|
|
|
357
|
|
|
|
|
|
|
|
358
|
|
|
|
|
|
|
#===============================================================================
|
359
|
|
|
|
|
|
|
# the complete PNG file
|
360
|
|
|
|
|
|
|
#===============================================================================
|
361
|
|
|
|
|
|
|
our $png_parser = Struct("png",
|
362
|
|
|
|
|
|
|
Magic("\x89PNG\r\n\x1a\n"),
|
363
|
|
|
|
|
|
|
$image_header_chunk,
|
364
|
|
|
|
|
|
|
GreedyRange($chunk),
|
365
|
|
|
|
|
|
|
);
|
366
|
|
|
|
|
|
|
|
367
|
|
|
|
|
|
|
require Exporter;
|
368
|
|
|
|
|
|
|
our @ISA = qw(Exporter);
|
369
|
|
|
|
|
|
|
our @EXPORT = qw($png_parser);
|
370
|
|
|
|
|
|
|
|
371
|
|
|
|
|
|
|
1;
|
372
|
|
|
|
|
|
|
|
373
|
|
|
|
|
|
|
__END__
|