1PDF::Builder::Resource:U:sXeOrbjCeoPcnDttF:r::i:IbBmuuatigeledd:e:PrPe:Nr:GlR_eIDsPooLcu(ur3mc)een:t:aXtOibojnect::Image::PNG_IPL(3)
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6 PDF::Builder::Resource::XObject::Image::PNG_IPL - support routines for
7 PNG image library (using Image::PNG::Libpng). Inherits from
8 PDF::Builder::Resource::XObject::Image
9
11 $res = PDF::Builder::Resource::XObject::Image::PNG_IPL->new($pdf,
12 $file, %opts)
13 Returns a PNG-image object. $pdf is the PDF object being added to,
14 $file is the input PNG file, and the optional $name of the new
15 parent image object defaults to PxAAA.
16 If the Image::PNG::Libpng package is installed, and its use is not
18 suppressed via the "nouseIPL" flag (see Builder documentation for
19 "image_png"), the PNG_IPL library will be used. Otherwise, the PNG
20 library will be used instead.
21 opts:
23 'notrans' => 1
25 No transparency -- ignore tRNS chunk if provided, ignore Alpha
26 channel if provided.
27 'force8bps' => 1
29 If the PNG source is 16bps, tell the libpng library to strip
30 down all channels to 8bps, permitting use on PDF 1.4 output.
31 'name' => 'string'
33 This is the name you can give for the PNG image object. The
34 default is Pxnnnn.
35 Supported PNG types
37 (0) Gray scale of depth 1, 2, 4, 8, or 16 bits per pixel (2, 4, 16, 256,
38 or 65536 gray levels). Full transparency (of one 16-bit gray value)
39 via the tRNS chunk is allowed, unless the notrans option specifies
40 that it be ignored.
41 (2) RGB truecolor with 8 or 16 bits per sample (3 samples: 16.7 million
43 or 281.5 trillion colors). Full transparency (of one 3x16-bit RGB
44 color value) via the tRNS chunk is allowed, unless the notrans
45 option specifies that it be ignored.
46 (3) Palette color with 1, 2, 4, or 8 bits per pixel (2, 4, 16, or 256
48 color table/palette entries). 16 bpp is not currently supported by
49 PNG or PDF. Partial transparency (8-bit Alpha) for each palette
50 entry via the tRNS chunk is allowed, unless the notrans option
51 specifies that it be ignored (all entries fully opaque).
52 (4) Gray scale of depth 8 or 16 bits per pixel plus equal-sized Alpha
54 channel (256 or 65536 gray levels and 256 or 65536 levels of
55 transparency). The Alpha channel is ignored if the notrans
56 option is given. The tRNS chunk is not permitted.
57 (5) B<RESERVED> for grayscale via palette + Alpha channel
59 (6) RGB truecolor with 8 or 16 bits per sample, with equal-sized
61 Alpha channel (256 or 65536 levels of transparency). The Alpha
62 channel is ignored if the notrans option is given. The tRNS
63 chunk is not permitted.
64 (7) B<RESERVED> for truecolor via palette + Alpha channel
66 In all cases, 16 bits per sample forces PDF 1.5 (or higher) output,
68 unless you give the "force8bps" option, to "strip" 16 bit samples to 8
69 bits, and permit PDF 1.4-compatible output. The libpng.a library is
70 assuming standard "network" bit and byte ordering (Big Endian),
71 although flags might be added to change this.
72 The transparency chunk (tRNS) will specify one gray level entry or one
74 RGB entry to be treated as transparent (Alpha = 0). For palette color,
75 up to 256 palette entry 8-bit Alpha values are specified (256 levels of
76 transparency, from 0 = transparent to 255 = opaque).
77 Only a limited number of chunks are handled: IHDR, IDAT (internally),
79 PLTE, tRNS, and IEND (internally). All other chunks are ignored at this
80 time. Filters and compression applied to data is handled internally by
81 libpng.a -- there may be unsupported methods.
82 $mode = $png->usesLib()
84 Returns 1 if Image::PNG::Libpng installed and used, 0 if not
85 installed, or -1 if installed but not used (nouseIPL option given
86 to "image_png").
87 Caution: this method can only be used after the image object has
89 been created. It can't tell you whether Image::PNG::Libpng is
90 available in advance of actually using it, in case you want to use
91 some functionality available only in PNG_IPL. See the PDF::Builder
92 LA_IPL() call if you need to know in advance.
93perl v5.36.0 PDF::B2u0i2l3d-e0r1:-:2R3esource::XObject::Image::PNG_IPL(3)