PngExtendedParams Object (IPngExtendedParams Interface)

This object provides functionality for tuning the parameters of saving a black-and-white image to PNG format (IFF_Png format) using the IImage::WriteToFile method. A pointer to this object is passed into the IImage::WriteToFile method as an input parameter, and thus affects the properties of the resulting image. All properties of a newly created object of this type are set to reasonable defaults. See the description of particular property for its default value.

The PngExtendedParams object is a persistent object. This means that the object's current state can be written to persistent storage: an area in the global memory or a disk file. Later, the object can be re-created by reading the object's state from persistent storage. The following methods provide persistence of the object: SaveToFile, LoadFromFile, SaveToMemory, and LoadFromMemory.


Name Type Description
Application Engine, read-only Returns the Engine object.
TransparentColor int

Sets the color which must be replaced by transparent areas when saving the image in PNG format.

Only black and white colors are currently supported.

Note: The int value is calculated from the RGB triplet using the formula: (red value) + (256 x green value) + (65536 x blue value), where red value is the first triplet component, green value is the second triplet component, blue value is the third triplet component. For example, the int value of the color white equals 16777215.

The default value of this property is -1, which means that no colors will be replaced with transparency.


Name Description
CopyFrom Initializes properties of the current object with values of similar properties of another object.
LoadFromFile Restores the object contents from a file on disk.
LoadFromMemory Restores the object contents from the global memory.
SaveToFile Saves the object contents into a file on disk.
SaveToMemory Saves the object contents into the global memory.

Output parameter

This object is the output parameter of the CreatePngExtendedParams method of the Engine object.

Input parameter

This object is the input parameter of the WriteToFile method of the Image object.

See also


Working with Images

Working with Properties

24.03.2023 8:51:52

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