/ 
Image-PNG-0.06
River stage zero No dependents
/ Image::PNG::Const

NAME

Image::PNG::Const

SYNOPSIS

# Get the constants you need:
use Image::PNG::Const qw/PNG_TRANSFORM_INVERT_ALPHA
                        PNG_COLOR_MASK_ALPHA/;
# Get everything:
use Image::PNG::Const ':all';

This module contains no functions, only constants.

CONSTANTS

This file contains constants extracted from the header file of the PNG library, png.h. The constants in this file are

PNG_TEXT_COMPRESSION_NONE_WR = -3
PNG_TEXT_COMPRESSION_zTXt_WR = -2
PNG_TEXT_COMPRESSION_NONE = -1
PNG_TEXT_COMPRESSION_zTXt = 0
PNG_ITXT_COMPRESSION_NONE = 1
PNG_ITXT_COMPRESSION_zTXt = 2
PNG_COLOR_MASK_PALETTE = 1
PNG_COLOR_MASK_COLOR = 2
PNG_COLOR_MASK_ALPHA = 4
PNG_COLOR_TYPE_GRAY = 0
PNG_COLOR_TYPE_PALETTE = (2 | 1)
PNG_COLOR_TYPE_RGB = (2)
PNG_COLOR_TYPE_RGB_ALPHA = (2 | 4)
PNG_COLOR_TYPE_GRAY_ALPHA = (4)
PNG_COLOR_TYPE_RGBA = (2 | 4)
PNG_COLOR_TYPE_GA = (4)
PNG_COMPRESSION_TYPE_BASE = 0
PNG_COMPRESSION_TYPE_DEFAULT = 0
PNG_FILTER_TYPE_BASE = 0
PNG_INTRAPIXEL_DIFFERENCING = 64
PNG_FILTER_TYPE_DEFAULT = 0
PNG_INTERLACE_NONE = 0
PNG_INTERLACE_ADAM7 = 1
PNG_OFFSET_PIXEL = 0
PNG_OFFSET_MICROMETER = 1
PNG_EQUATION_LINEAR = 0
PNG_EQUATION_BASE_E = 1
PNG_EQUATION_ARBITRARY = 2
PNG_EQUATION_HYPERBOLIC = 3
PNG_SCALE_UNKNOWN = 0
PNG_SCALE_METER = 1
PNG_SCALE_RADIAN = 2
PNG_RESOLUTION_UNKNOWN = 0
PNG_RESOLUTION_METER = 1
PNG_sRGB_INTENT_PERCEPTUAL = 0
PNG_sRGB_INTENT_RELATIVE = 1
PNG_sRGB_INTENT_SATURATION = 2
PNG_sRGB_INTENT_ABSOLUTE = 3
PNG_KEYWORD_MAX_LENGTH = 79
PNG_MAX_PALETTE_LENGTH = 256
PNG_INFO_gAMA = 0x0001
PNG_INFO_sBIT = 0x0002
PNG_INFO_cHRM = 0x0004
PNG_INFO_PLTE = 0x0008
PNG_INFO_tRNS = 0x0010
PNG_INFO_bKGD = 0x0020
PNG_INFO_hIST = 0x0040
PNG_INFO_pHYs = 0x0080
PNG_INFO_oFFs = 0x0100
PNG_INFO_tIME = 0x0200
PNG_INFO_pCAL = 0x0400
PNG_INFO_sRGB = 0x0800
PNG_INFO_iCCP = 0x1000
PNG_INFO_sPLT = 0x2000
PNG_INFO_sCAL = 0x4000
PNG_INFO_IDAT = 0x8000
PNG_TRANSFORM_IDENTITY = 0x0000
PNG_TRANSFORM_STRIP_16 = 0x0001
PNG_TRANSFORM_STRIP_ALPHA = 0x0002
PNG_TRANSFORM_PACKING = 0x0004
PNG_TRANSFORM_PACKSWAP = 0x0008
PNG_TRANSFORM_EXPAND = 0x0010
PNG_TRANSFORM_INVERT_MONO = 0x0020
PNG_TRANSFORM_SHIFT = 0x0040
PNG_TRANSFORM_BGR = 0x0080
PNG_TRANSFORM_SWAP_ALPHA = 0x0100
PNG_TRANSFORM_SWAP_ENDIAN = 0x0200
PNG_TRANSFORM_INVERT_ALPHA = 0x0400
PNG_TRANSFORM_STRIP_FILLER = 0x0800
PNG_TRANSFORM_STRIP_FILLER_BEFORE = 0x0800
PNG_TRANSFORM_STRIP_FILLER_AFTER = 0x1000
PNG_TRANSFORM_GRAY_TO_RGB = 0x2000
PNG_FLAG_MNG_EMPTY_PLTE = 0x01
PNG_FLAG_MNG_FILTER_64 = 0x04
PNG_ALL_MNG_FEATURES = 0x05
PNG_FILLER_BEFORE = 0
PNG_FILLER_AFTER = 1
PNG_BACKGROUND_GAMMA_UNKNOWN = 0
PNG_BACKGROUND_GAMMA_SCREEN = 1
PNG_BACKGROUND_GAMMA_FILE = 2
PNG_BACKGROUND_GAMMA_UNIQUE = 3
PNG_CRC_DEFAULT = 0
PNG_CRC_ERROR_QUIT = 1
PNG_CRC_WARN_DISCARD = 2
PNG_CRC_WARN_USE = 3
PNG_CRC_QUIET_USE = 4
PNG_CRC_NO_CHANGE = 5
PNG_NO_FILTERS = 0x00
PNG_FILTER_NONE = 0x08
PNG_FILTER_SUB = 0x10
PNG_FILTER_UP = 0x20
PNG_FILTER_AVG = 0x40
PNG_FILTER_PAETH = 0x80
PNG_ALL_FILTERS = (0x08 | 0x10 | 0x20 | 0x40 | 0x80)
PNG_FILTER_VALUE_NONE = 0
PNG_FILTER_VALUE_SUB = 1
PNG_FILTER_VALUE_UP = 2
PNG_FILTER_VALUE_AVG = 3
PNG_FILTER_VALUE_PAETH = 4
PNG_FILTER_HEURISTIC_DEFAULT = 0
PNG_FILTER_HEURISTIC_UNWEIGHTED = 1
PNG_FILTER_HEURISTIC_WEIGHTED = 2
PNG_DESTROY_WILL_FREE_DATA = 1
PNG_SET_WILL_FREE_DATA = 1
PNG_USER_WILL_FREE_DATA = 2
PNG_FREE_HIST = 0x0008
PNG_FREE_ICCP = 0x0010
PNG_FREE_SPLT = 0x0020
PNG_FREE_ROWS = 0x0040
PNG_FREE_PCAL = 0x0080
PNG_FREE_SCAL = 0x0100
PNG_FREE_UNKN = 0x0200
PNG_FREE_LIST = 0x0400
PNG_FREE_PLTE = 0x1000
PNG_FREE_TRNS = 0x2000
PNG_FREE_TEXT = 0x4000
PNG_FREE_ALL = 0x7fff
PNG_FREE_MUL = 0x4220
PNG_HANDLE_CHUNK_AS_DEFAULT = 0
PNG_HANDLE_CHUNK_NEVER = 1
PNG_HANDLE_CHUNK_IF_SAFE = 2
PNG_HANDLE_CHUNK_ALWAYS = 3
PNG_IO_NONE = 0x0000
PNG_IO_READING = 0x0001
PNG_IO_WRITING = 0x0002
PNG_IO_SIGNATURE = 0x0010
PNG_IO_CHUNK_HDR = 0x0020
PNG_IO_CHUNK_DATA = 0x0040
PNG_IO_CHUNK_CRC = 0x0080
PNG_IO_MASK_OP = 0x000f
PNG_IO_MASK_LOC = 0x00f0
PNG_HAVE_IHDR = 0x01
PNG_HAVE_PLTE = 0x02
PNG_HAVE_IDAT = 0x04
PNG_AFTER_IDAT = 0x08
PNG_HAVE_IEND = 0x10
PNG_HAVE_gAMA = 0x20
PNG_HAVE_cHRM = 0x40

EXPORTS

Nothing is exported by default, but all the symbols in this module can be exported on request. There is one export tag, 'all', which exports all the symbols in this module:

use Image::PNG::Const ':all';

ABOUT THIS MODULE

This Perl module was automatically created from png.h. To rebuild it, run the script "strip-constants.pl" in the top directory of the Image::PNG distribution. You need to have the Template module installed. You may need to edit the script somewhat, depending on your environment.

The template for creating Const.pm is in directory tmpl in the Image::PNG distribution. Its name is Const.pm.tmpl.

AUTHOR

Ben Bullock, <bkb@cpan.org>

COPYRIGHT & LICENCE

The Image::PNG package and associated files are copyright (C) 2011 Ben Bullock.

You can use, copy, modify and redistribute Image::PNG and associated files under the Perl Artistic Licence or the GNU General Public Licence.

SUPPORT

Mailing list

There is a mailing list at http://groups.google.com/group/perlimagepng. You don't need to be a member of the list to post messages to the list or participate in discussions. Your messages may be held for moderation though.

If you have anything at all to say about the module, whether it is bug reports, feature requests, or anything else, I'd prefer to discuss it on the mailing list because that way there is a public record which everyone can access, rather than being restricted to email. That means that, for example, if someone else takes over maintaining this module, they can easily access records of previous discussions.

CPAN stuff

There is a bug tracker at .

FOR PROGRAMMERS

(This section is only for people who want to fix a bug or add an improvement to this module, and who want to share the change with other people by adding it to the public version of this module.)

If you want to alter this module, note very carefully that the distributed files are not actually the source code of the module. The source code lives in the "tmpl" directory of the distribution and the distribution is created via scripts.

The original files of this distribution make very heavy use of the Template Perl module in order to cut down the amount of repetitive stuff which needs to be put into various source and documentation files. If you plan to alter the C file, you may also need a program called "cfunctions" which you can download from sourceforge, which generates the header file perl-libpng.h from perl-libpng.c.