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 $name, %opts)
13 $res = PDF::Builder::Resource::XObject::Image::PNG->new($pdf, $file,
14 $name)
15 $res = PDF::Builder::Resource::XObject::Image::PNG->new($pdf, $file)
16 Returns a PNG-image object. $pdf is the PDF object being added to,
18 $file is the input PNG file, and the optional $name of the new parent
19 image object defaults to PxAAA.
20 If the Image::PNG::Libpng package is installed, the PNG_IPL library
22 will be used instead of the PNG library. In such a case, use of the PNG
23 library may be forced via the "-nouseIPL" flag (see Builder
24 documentation for "image_png()").
25 opts: -notrans
27 No transparency -- ignore tRNS chunk if provided, ignore Alpha channel
29 if provided.
30 Supported PNG types
32 (0) Gray scale of depth 1, 2, 4, or 8 bits per pixel (2, 4, 16, or 256
33 gray levels). 16 bpp is not currently supported (a PNG with 16 bpp
34 is a fatal error). Full transparency (of one 8-bit gray value) via
35 the tRNS chunk is allowed, unless the -notrans option specifies
36 that it be ignored.
37 (2) RGB 24-bit truecolor with 8 bits per sample (16.7 million colors).
39 16 bps is not currently supported (a PNG with 16 bps is a fatal
40 error). Full transparency (of one 3x8-bit RGB color value) via the
41 tRNS chunk is allowed, unless the -notrans option specifies that it
42 be ignored.
43 (3) Palette color with 1, 2, 4, or 8 bits per pixel (2, 4, 16, or 256
45 color table/palette entries). 16 bpp is not currently supported by
46 PNG or PDF. Partial transparency (8-bit Alpha) for each palette
47 entry via the tRNS chunk is allowed, unless the -notrans option
48 specifies that it be ignored (all entries fully opaque).
49 (4) Gray scale of depth 8 bits per pixel plus 8-bit Alpha channel (256
51 gray levels and 256 levels of transparency). 16 bpp is not
52 currently supported (a PNG with 16 bpp is a fatal error). The Alpha
53 channel is ignored if the -notrans option is given. The tRNS chunk
54 is not permitted.
55 (6) RGB 24-bit truecolor with 8 bits per sample (16.7 million colors)
57 plus 8-bit Alpha channel (256 levels of transparency). 16 bps is not
58 currently supported (a PNG with 16 bps is a fatal error). The Alpha
59 channel is ignored if the -notrans option is given. The tRNS chunk
60 is not permitted.
61 In all cases, 16 bits per sample are not implemented. A fatal error
63 will be returned if a PNG image with 16-bps data is supplied. The code
64 is assuming standard "network" bit ordering (Big Endian). Interlaced
65 (progressive) display images are not supported. Use the PNG_IPL version
66 if you need to support 16 bps or interlaced images.
67 The transparency chunk (tRNS) will specify one gray level entry or one
69 RGB entry to be treated as transparent (Alpha = 0). For palette color,
70 up to 256 palette entry 8-bit Alpha values are specified (256 levels of
71 transparency, from 0 = transparent to 255 = opaque).
72 Only a limited number of chunks are handled: IHDR, IDAT (internally),
74 PLTE, tRNS, and IEND (internally). All other chunks are ignored at this
75 time. Certain filters and compressions applied to data will be handled,
76 but there may be unsupported methods.
77 $mode = $png->usesLib()
79 Returns 1 if Image::PNG::Libpng installed and used, 0 if not
80 installed, or -1 if installed but not used (-nouseIPL option given
81 to "image_png").
82 Caution: this method can only be used after the image object has
84 been created. It can't tell you whether Image::PNG::Libpng is
85 available in advance of actually using it, in case you want to use
86 some functionality available only in PNG_IPL. See the PDF::Builder
87 LA_IPL() call if you need to know in advance.
88perl v5.34.0 PD2F0:2:1B-u0i7l-d2e2r::Resource::XObject::Image::PNG(3)