1PDF::Builder::Resource:U:sXeOrbjCeocntt:r:iPIbDmuFat:ge:edB:u:PiPelNrdGle(r3D:)o:cRuemseonutractei:o:nXObject::Image::PNG(3)
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6 PDF::Builder::Resource::XObject::Image::PNG - support routines for PNG
7 image library (using pure Perl code). Inherits from
8 PDF::Builder::Resource::XObject::Image
9
11 $res = PDF::Builder::Resource::XObject::Image::PNG->new($pdf, $file,
12 %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, the PNG_IPL library
18 will be used instead of the PNG library. In such a case, use of the
19 PNG library may be forced via the "nouseIPL" flag (see Builder
20 documentation for image_png()).
21 opts:
23 'notrans' => 1
25 No transparency -- ignore tRNS chunk if provided, ignore Alpha
26 channel if provided.
27 'name' => 'string'
29 This is the name you can give for the PNG image object. The
30 default is Pxnnnn.
31 Supported PNG types
33 (0) Gray scale of depth 1, 2, 4, or 8 bits per pixel (2, 4, 16, or 256
34 gray levels). 16 bpp is not currently supported (a PNG with 16 bpp
35 is a fatal error). Full transparency (of one 8-bit gray value) via
36 the tRNS chunk is allowed, unless the notrans option specifies
37 that it be ignored.
38 (2) RGB 24-bit truecolor with 8 bits per sample (16.7 million colors).
40 16 bps is not currently supported (a PNG with 16 bps is a fatal
41 error). Full transparency (of one 3x8-bit RGB color value) via the
42 tRNS chunk is allowed, unless the notrans option specifies that it
43 be ignored.
44 (3) Palette color with 1, 2, 4, or 8 bits per pixel (2, 4, 16, or 256
46 color table/palette entries). 16 bpp is not currently supported by
47 PNG or PDF. Partial transparency (8-bit Alpha) for each palette
48 entry via the tRNS chunk is allowed, unless the notrans option
49 specifies that it be ignored (all entries fully opaque).
50 (4) Gray scale of depth 8 bits per pixel plus 8-bit Alpha channel (256
52 gray levels and 256 levels of transparency). 16 bpp is not
53 currently supported (a PNG with 16 bpp is a fatal error). The Alpha
54 channel is ignored if the notrans option is given. The tRNS chunk
55 is not permitted.
56 (6) RGB 24-bit truecolor with 8 bits per sample (16.7 million colors)
58 plus 8-bit Alpha channel (256 levels of transparency). 16 bps is not
59 currently supported (a PNG with 16 bps is a fatal error). The Alpha
60 channel is ignored if the notrans option is given. The tRNS chunk
61 is not permitted.
62 In all cases, 16 bits per sample are not implemented. A fatal error
64 will be returned if a PNG image with 16-bps data is supplied. The code
65 is assuming standard "network" bit ordering (Big Endian). Interlaced
66 (progressive) display images are not supported. Use the PNG_IPL version
67 if you need to support 16 bps or interlaced images.
68 The transparency chunk (tRNS) will specify one gray level entry or one
70 RGB entry to be treated as transparent (Alpha = 0). For palette color,
71 up to 256 palette entry 8-bit Alpha values are specified (256 levels of
72 transparency, from 0 = transparent to 255 = opaque).
73 Only a limited number of chunks are handled: IHDR, IDAT (internally),
75 PLTE, tRNS, and IEND (internally). All other chunks are ignored at this
76 time. Certain filters and compressions applied to data will be handled,
77 but there may be unsupported methods.
78 $mode = $png->usesLib()
80 Returns 1 if Image::PNG::Libpng installed and used, 0 if not
81 installed, or -1 if installed but not used (nouseIPL option given
82 to "image_png").
83 Caution: this method can only be used after the image object has
85 been created. It can't tell you whether Image::PNG::Libpng is
86 available in advance of actually using it, in case you want to use
87 some functionality available only in PNG_IPL. See the PDF::Builder
88 LA_IPL() call if you need to know in advance.
89perl v5.36.0 PD2F0:2:3B-u0i1l-d2e3r::Resource::XObject::Image::PNG(3)