Collaboration diagram for PNG - Portable Network Graphic Format:
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Description
- Access to the PNG file format uses libpng version 1.6.23.
http://www.libpng.org
Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson
Features
Data Types: Byte and UShort
Color Spaces: Gray, RGB, MAP and Binary
Compressions:
DEFLATE - LZ77 variation (ZIP) [default]
Only one image.
Can have an alpha channel.
Internally the components are always packed.
Internally the lines are arranged from top down to bottom.
Handle(1) returns png_structp libPNG structure.
Attributes:
ZIPQuality IM_INT (1) [1-9, default 6] (write only)
ResolutionUnit (string) ["DPC", "DPI"]
XResolution, YResolution IM_FLOAT (1)
Interlaced (same as Progressive) IM_INT (1 | 0) default 0
Gamma IM_FLOAT (1)
WhitePoint IMFLOAT (2)
PrimaryChromaticities IMFLOAT (6)
XPosition, YPosition IM_FLOAT (1)
sRGBIntent IM_INT (1) [0: Perceptual, 1: Relative colorimetric, 2: Saturation, 3: Absolute colorimetric]
TransparencyMap IM_BYTE (N) (for MAP images is the alpha value of the corresponding palette index)
TransparencyIndex IM_BYTE (1) (for MAP images is the first index that has minimum alpha in TransparencyMap, for GRAY images is the index that it is fully transparent)
TransparencyColor IM_BYTE (3) (for RGB images is the color that is full transparent)
CalibrationName, CalibrationUnits (string)
CalibrationLimits IM_INT (2)
CalibrationEquation IM_BYTE (1) [0-Linear,1-Exponential,2-Arbitrary,3-HyperbolicSine)]
CalibrationParam (string) [params separated by '\\n']
Title, Author, Description, Copyright, DateTime (string)
Software, Disclaimer, Warning, Source, Comment, ... (string)
DateTimeModified (string) [when writing uses the current system time]
ICCProfile IM_BYTE (N)
ScaleUnit (string) ["meters", "radians"]
XScale, YScale IM_FLOAT (1)
Comments:
When saving PNG image with TransparencyIndex or TransparencyMap, TransparencyMap has precedence,
so set it to NULL if you changed TransparencyIndex.
Attributes set after the image are ignored.
