Image:...::Const(3pm)

📦

version 0.60 · 9 versions

🌸 NAME 🌸

okay so this is Image:...::Const(3pm), a User Contributed Perl Documentation page, and it's giving constants-only main character energy 💅

Image::PNG::Const — Constants for libpng. That's the whole name, bestie — no functions hiding in here, just constants.

✨ SYNOPSIS ✨

# Get just 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 is a helper for Image::PNG::Libpng. It contains no functions — only constants, and honestly that's the vibe 🫶

💅 CONSTANTS 💅

This file contains the following constants, straight from the header file of the PNG library, png.h — here's the whole iconic lineup:

PNG_AFTER_IDAT — has value 0x08.
PNG_ALL_FILTERS — has value ((0x08 | 0x10 | 0x20) | 0x40 | 0x80).
PNG_ALL_MNG_FEATURES — has value 0x05.
PNG_ALPHA_ASSOCIATED — has value 1.
PNG_ALPHA_BROKEN — has value 3.
PNG_ALPHA_OPTIMIZED — has value 2.
PNG_ALPHA_PNG — has value 0.
PNG_ALPHA_PREMULTIPLIED — has value 1.
PNG_ALPHA_STANDARD — has value 1.
PNG_ARM_NEON — has value 0.
PNG_BACKGROUND_GAMMA_FILE — has value 2.
PNG_BACKGROUND_GAMMA_SCREEN — has value 1.
PNG_BACKGROUND_GAMMA_UNIQUE — has value 3.
PNG_BACKGROUND_GAMMA_UNKNOWN — has value 0.
PNG_BLEND_OP_OVER — has value 0x01.
PNG_BLEND_OP_SOURCE — has value 0x00.
PNG_COLOR_MASK_ALPHA — has value 4.
PNG_COLOR_MASK_COLOR — has value 2.
PNG_COLOR_MASK_PALETTE — has value 1.
PNG_COLOR_TYPE_GA — has value (4).
PNG_COLOR_TYPE_GRAY — has value 0.
PNG_COLOR_TYPE_GRAY_ALPHA — has value (4).
PNG_COLOR_TYPE_PALETTE — has value (2 | 1).
PNG_COLOR_TYPE_RGB — has value (2).
PNG_COLOR_TYPE_RGBA — has value (2 | 4).
PNG_COLOR_TYPE_RGB_ALPHA — has value (2 | 4).
PNG_COMPRESSION_TYPE_BASE — has value 0.
PNG_COMPRESSION_TYPE_DEFAULT — has value 0.
PNG_CRC_DEFAULT — has value 0.
PNG_CRC_ERROR_QUIT — has value 1.
PNG_CRC_NO_CHANGE — has value 5.
PNG_CRC_QUIET_USE — has value 4.
PNG_CRC_WARN_DISCARD — has value 2.
PNG_CRC_WARN_USE — has value 3.
PNG_DEFAULT_sRGB — has value -1.
PNG_DISPOSE_OP_BACKGROUND — has value 0x01.
PNG_DISPOSE_OP_NONE — has value 0x00.
PNG_DISPOSE_OP_PREVIOUS — has value 0x02.
PNG_EQUATION_ARBITRARY — has value 2.
PNG_EQUATION_BASE_E — has value 1.
PNG_EQUATION_HYPERBOLIC — has value 3.
PNG_EQUATION_LINEAR — has value 0.
PNG_ERROR_ACTION_ERROR — has value 3.
PNG_ERROR_ACTION_NONE — has value 1.
PNG_ERROR_ACTION_WARN — has value 2.
PNG_FAST_FILTERS — has value (0x08 | 0x10 | 0x20).
PNG_FILLER_AFTER — has value 1.
PNG_FILLER_BEFORE — has value 0.
PNG_FILTER_AVG — has value 0x40.
PNG_FILTER_HEURISTIC_DEFAULT — has value 0.
PNG_FILTER_HEURISTIC_UNWEIGHTED — has value 1.
PNG_FILTER_HEURISTIC_WEIGHTED — has value 2.
PNG_FILTER_NONE — has value 0x08.
PNG_FILTER_PAETH — has value 0x80.
PNG_FILTER_SUB — has value 0x10.
PNG_FILTER_TYPE_BASE — has value 0.
PNG_FILTER_TYPE_DEFAULT — has value 0.
PNG_FILTER_UP — has value 0x20.
PNG_FILTER_VALUE_AVG — has value 3.
PNG_FILTER_VALUE_NONE — has value 0.
PNG_FILTER_VALUE_PAETH — has value 4.
PNG_FILTER_VALUE_SUB — has value 1.
PNG_FILTER_VALUE_UP — has value 2.
PNG_FLAG_MNG_EMPTY_PLTE — has value 0x01.
PNG_FLAG_MNG_FILTER_64 — has value 0x04.
PNG_FORMAT_ABGR — has value (((0x02|0x10)|0x01)|0x20).
PNG_FORMAT_ABGR_COLORMAP — has value ((((0x02|0x10)|0x01)|0x20)|0x08).
PNG_FORMAT_AG — has value (0x01|0x20).
PNG_FORMAT_ARGB — has value ((0x02|0x01)|0x20).
PNG_FORMAT_ARGB_COLORMAP — has value (((0x02|0x01)|0x20)|0x08).
PNG_FORMAT_BGR — has value (0x02|0x10).
PNG_FORMAT_BGRA — has value ((0x02|0x10)|0x01).
PNG_FORMAT_BGRA_COLORMAP — has value (((0x02|0x10)|0x01)|0x08).
PNG_FORMAT_BGR_COLORMAP — has value ((0x02|0x10)|0x08).
PNG_FORMAT_FLAG_AFIRST — has value 0x20.
PNG_FORMAT_FLAG_ALPHA — has value 0x01.
PNG_FORMAT_FLAG_ASSOCIATED_ALPHA — has value 0x40.
PNG_FORMAT_FLAG_BGR — has value 0x10.
PNG_FORMAT_FLAG_COLOR — has value 0x02.
PNG_FORMAT_FLAG_COLORMAP — has value 0x08.
PNG_FORMAT_FLAG_LINEAR — has value 0x04.
PNG_FORMAT_GA — has value 0x01.
PNG_FORMAT_GRAY — has value 0.
PNG_FORMAT_LINEAR_RGB — has value (0x04|0x02).
PNG_FORMAT_LINEAR_Y — has value 0x04.
PNG_FORMAT_LINEAR_Y_ALPHA — has value (0x04|0x01).
PNG_FORMAT_RGB — has value 0x02.
PNG_FORMAT_RGBA — has value (0x02|0x01).
PNG_FORMAT_RGBA_COLORMAP — has value ((0x02|0x01)|0x08).
PNG_FORMAT_RGB_COLORMAP — has value (0x02|0x08).
PNG_FP_1 — has value 100000.
PNG_FP_HALF — has value 50000.
PNG_FP_MIN — has value (-PNG_FP_MAX).
PNG_FREE_ALL — has value 0xffff.
PNG_FREE_EXIF — has value 0x8000.
PNG_FREE_HIST — has value 0x0008.
PNG_FREE_ICCP — has value 0x0010.
PNG_FREE_MUL — has value 0x4220.
PNG_FREE_PCAL — has value 0x0080.
PNG_FREE_PLTE — has value 0x1000.
PNG_FREE_ROWS — has value 0x0040.
PNG_FREE_SCAL — has value 0x0100.
PNG_FREE_SPLT — has value 0x0020.
PNG_FREE_TEXT — has value 0x4000.
PNG_FREE_TRNS — has value 0x2000.
PNG_FREE_UNKN — has value 0x0200.
PNG_GAMMA_LINEAR — has value 100000.
PNG_GAMMA_MAC_18 — has value -2.
PNG_GAMMA_THRESHOLD — has value (PNG_GAMMA_THRESHOLD_FIXED*.00001).
PNG_GAMMA_sRGB — has value 220000.
PNG_HANDLE_CHUNK_ALWAYS — has value 3.
PNG_HANDLE_CHUNK_AS_DEFAULT — has value 0.
PNG_HANDLE_CHUNK_IF_SAFE — has value 2.
PNG_HANDLE_CHUNK_NEVER — has value 1.
PNG_HAVE_IHDR — has value 0x01.
PNG_HAVE_PLTE — has value 0x02.
PNG_IGNORE_ADLER32 — has value 8.
PNG_IMAGE_ERROR — has value 2.
PNG_IMAGE_FLAG_16BIT_sRGB — has value 0x04.
PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB — has value 0x01.
PNG_IMAGE_FLAG_FAST — has value 0x02.
PNG_IMAGE_VERSION — has value 1.
PNG_IMAGE_WARNING — has value 1.
PNG_INFO_IDAT — has value 0x8000.
PNG_INFO_PLTE — has value 0x0008.
PNG_INFO_acTL — has value 0x100000.
PNG_INFO_bKGD — has value 0x0020.
PNG_INFO_cHRM — has value 0x0004.
PNG_INFO_cICP — has value 0x20000.
PNG_INFO_cLLI — has value 0x40000.
PNG_INFO_eXIf — has value 0x10000.
PNG_INFO_fcTL — has value 0x200000.
PNG_INFO_fdAT — has value 0x400000.
PNG_INFO_gAMA — has value 0x0001.
PNG_INFO_hIST — has value 0x0040.
PNG_INFO_iCCP — has value 0x1000.
PNG_INFO_mDCV — has value 0x80000.
PNG_INFO_oFFs — has value 0x0100.
PNG_INFO_pCAL — has value 0x0400.
PNG_INFO_pHYs — has value 0x0080.
PNG_INFO_sBIT — has value 0x0002.
PNG_INFO_sCAL — has value 0x4000.
PNG_INFO_sPLT — has value 0x2000.
PNG_INFO_sRGB — has value 0x0800.
PNG_INFO_tIME — has value 0x0200.
PNG_INFO_tRNS — has value 0x0010.
PNG_INTERLACE_ADAM7 — has value 1.
PNG_INTERLACE_ADAM7_PASSES — has value 7.
PNG_INTERLACE_NONE — has value 0.
PNG_INTRAPIXEL_DIFFERENCING — has value 64.
PNG_IO_CHUNK_CRC — has value 0x0080.
PNG_IO_CHUNK_DATA — has value 0x0040.

part 1 stops here at PNG_IO_CHUNK_DATA — part 2 is literally right behind this with the rest of the constants ✨

PNG_IO_CHUNK_HDR — PNG_IO_CHUNK_HDR has value 0x0020.
PNG_IO_MASK_LOC — PNG_IO_MASK_LOC has value 0x00f0.
PNG_IO_MASK_OP — PNG_IO_MASK_OP has value 0x000f.
PNG_IO_NONE — PNG_IO_NONE has value 0x0000.
PNG_IO_READING — PNG_IO_READING has value 0x0001.
PNG_IO_SIGNATURE — PNG_IO_SIGNATURE has value 0x0010.
PNG_IO_WRITING — PNG_IO_WRITING has value 0x0002.
PNG_ITXT_COMPRESSION_NONE — PNG_ITXT_COMPRESSION_NONE has value 1.
PNG_ITXT_COMPRESSION_zTXt — PNG_ITXT_COMPRESSION_zTXt has value 2.
PNG_KEYWORD_MAX_LENGTH — PNG_KEYWORD_MAX_LENGTH has value 79.
PNG_MAXIMUM_INFLATE_WINDOW — PNG_MAXIMUM_INFLATE_WINDOW has value 2.
PNG_MAX_PALETTE_LENGTH — PNG_MAX_PALETTE_LENGTH has value 256.
PNG_MIPS_MMI — PNG_MIPS_MMI has value 12.
PNG_MIPS_MSA — PNG_MIPS_MSA has value 6.
PNG_NO_FILTERS — PNG_NO_FILTERS has value 0x00.
PNG_OFFSET_MICROMETER — PNG_OFFSET_MICROMETER has value 1.
PNG_OFFSET_PIXEL — PNG_OFFSET_PIXEL has value 0.
PNG_OPTION_INVALID — PNG_OPTION_INVALID has value 1.
PNG_OPTION_NEXT — PNG_OPTION_NEXT has value 16.
PNG_OPTION_OFF — PNG_OPTION_OFF has value 2.
PNG_OPTION_ON — PNG_OPTION_ON has value 3.
PNG_OPTION_UNSET — PNG_OPTION_UNSET has value 0.
PNG_POWERPC_VSX — PNG_POWERPC_VSX has value 10.
PNG_RESOLUTION_METER — PNG_RESOLUTION_METER has value 1.
PNG_RESOLUTION_UNKNOWN — PNG_RESOLUTION_UNKNOWN has value 0.
PNG_RGB_TO_GRAY_DEFAULT — PNG_RGB_TO_GRAY_DEFAULT has value (-1).
PNG_RISCV_RVV — PNG_RISCV_RVV has value 14.
PNG_SCALE_METER — PNG_SCALE_METER has value 1.
PNG_SCALE_RADIAN — PNG_SCALE_RADIAN has value 2.
PNG_SCALE_UNKNOWN — PNG_SCALE_UNKNOWN has value 0.
PNG_SKIP_sRGB_CHECK_PROFILE — PNG_SKIP_sRGB_CHECK_PROFILE has value 4.
PNG_TEXT_COMPRESSION_NONE — PNG_TEXT_COMPRESSION_NONE has value -1.
PNG_TEXT_COMPRESSION_NONE_WR — PNG_TEXT_COMPRESSION_NONE_WR has value -3.
PNG_TEXT_COMPRESSION_zTXt — PNG_TEXT_COMPRESSION_zTXt has value 0.
PNG_TEXT_COMPRESSION_zTXt_WR — PNG_TEXT_COMPRESSION_zTXt_WR has value -2.
PNG_TRANSFORM_BGR — PNG_TRANSFORM_BGR has value 0x0080.
PNG_TRANSFORM_EXPAND — PNG_TRANSFORM_EXPAND has value 0x0010.
PNG_TRANSFORM_EXPAND_16 — PNG_TRANSFORM_EXPAND_16 has value 0x4000.
PNG_TRANSFORM_GRAY_TO_RGB — PNG_TRANSFORM_GRAY_TO_RGB has value 0x2000.
PNG_TRANSFORM_IDENTITY — PNG_TRANSFORM_IDENTITY has value 0x0000.
PNG_TRANSFORM_INVERT_ALPHA — PNG_TRANSFORM_INVERT_ALPHA has value 0x0400.
PNG_TRANSFORM_INVERT_MONO — PNG_TRANSFORM_INVERT_MONO has value 0x0020.
PNG_TRANSFORM_PACKING — PNG_TRANSFORM_PACKING has value 0x0004.
PNG_TRANSFORM_PACKSWAP — PNG_TRANSFORM_PACKSWAP has value 0x0008.
PNG_TRANSFORM_SCALE_16 — PNG_TRANSFORM_SCALE_16 has value 0x8000.
PNG_TRANSFORM_SHIFT — PNG_TRANSFORM_SHIFT has value 0x0040.
PNG_TRANSFORM_STRIP_16 — PNG_TRANSFORM_STRIP_16 has value 0x0001.
PNG_TRANSFORM_STRIP_ALPHA — PNG_TRANSFORM_STRIP_ALPHA has value 0x0002.
PNG_TRANSFORM_STRIP_FILLER — PNG_TRANSFORM_STRIP_FILLER has value 0x0800.
PNG_TRANSFORM_STRIP_FILLER_AFTER — PNG_TRANSFORM_STRIP_FILLER_AFTER has value 0x1000.
PNG_TRANSFORM_STRIP_FILLER_BEFORE — PNG_TRANSFORM_STRIP_FILLER_BEFORE has value 0x0800. (yep bestie, same number as PNG_TRANSFORM_STRIP_FILLER up there, i'm literally just reading the page 👀)
PNG_TRANSFORM_SWAP_ALPHA — PNG_TRANSFORM_SWAP_ALPHA has value 0x0100.
PNG_TRANSFORM_SWAP_ENDIAN — PNG_TRANSFORM_SWAP_ENDIAN has value 0x0200.
PNG_sRGB_INTENT_ABSOLUTE — PNG_sRGB_INTENT_ABSOLUTE has value 3.
PNG_sRGB_INTENT_PERCEPTUAL — PNG_sRGB_INTENT_PERCEPTUAL has value 0.
PNG_sRGB_INTENT_RELATIVE — PNG_sRGB_INTENT_RELATIVE has value 1.
PNG_sRGB_INTENT_SATURATION — PNG_sRGB_INTENT_SATURATION has value 2.

🌈 EXPORTS 🌈

Okay so nothing is exported by default — like, zero, nada, the module keeps all its little symbols to itself unless you ask nicely 🎀

But!! every single symbol in this module can be exported on request. And there's exactly one export tag, called 'all', which — you guessed it — exports all the symbols in this module ✨

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

That's it. That's the whole vibe. One tag, everything comes out to play 🫶

🦋 ABOUT THIS MODULE 🦋

This Perl module was generated from the file png.h supplied with version 1.6.45 of libpng. So like, it didn't get hand-typed by a person drinking matcha — it was generated from the header 💅 iykyk

👑 AUTHOR 👑

Ben Bullock, <benkasminbullock@gmail.com> — shoutout to the icon who made all these constants exist for us 😭💖

💜 COPYRIGHT & LICENCE 💜

You can use, copy, modify and redistribute this package and associated files under the Perl Artistic Licence or the GNU General Public Licence. Pick your fighter, bestie, both are legit 🌸

and that's the whole page!! every constant accounted for, no cap, not a single one left behind 🧚💫

perl v5.42.3 · 2026-08-19 — mwah, that's the source, version and date right there, go off calendar 🎀🫶✨

📦 where this page comes from

ubuntu stonking: libimage-png-libpng-perl 0.60-1build1 · Artistic-1.0-Perl OR GPL-1.0-or-later
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on 2026-11-06: a language model's rewrite of the original, under its terms