> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abbyy.com/llms.txt
> Use this file to discover all available pages before exploring further.
# 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](/fine-reader/engine/api-reference/image-related-objects/image/writetofile-method) 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. Later, the object can be re-created by reading the object's state from the persistent storage. The following methods provide persistence of the object:
Linux: [SaveToFile](/fine-reader/engine/api-reference/supplementary-objects-and-methods/savetofile-method), and [LoadFromFile](/fine-reader/engine/api-reference/supplementary-objects-and-methods/loadfromfile-method)
Windows [SaveToFile](/fine-reader/engine/api-reference/supplementary-objects-and-methods/savetofile-method), [LoadFromFile](/fine-reader/engine/api-reference/supplementary-objects-and-methods/loadfromfile-method), [SaveToMemory](/fine-reader/engine/api-reference/supplementary-objects-and-methods/savetomemory-method), and [LoadFromMemory](/fine-reader/engine/api-reference/supplementary-objects-and-methods/loadfrommemory-method).
## Properties
| Name | Type | Description |
| ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Application | [Engine](/fine-reader/engine/api-reference/engine-object-iengine-interface), [read-only](/fine-reader/engine/guided-tour/advanced-techniques/programming-aspects/working-with-properties#readonly_properties) | Returns the Engine object. |
| TransparentColor | [int](/fine-reader/engine/guided-tour/advanced-techniques/programming-aspects/working-with-properties) | 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. 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. |
## Methods
| Name | Description |
| --------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| [CopyFrom](/fine-reader/engine/visual-components-reference/supplementary-objects/spellwordcollection/copyfrom-method) | Initializes properties of the current object with values of similar properties of another object. |
| [LoadFromFile](/fine-reader/engine/api-reference/supplementary-objects-and-methods/loadfromfile-method) | Restores the object contents from a file on disk. |
| [LoadFromMemory](/fine-reader/engine/api-reference/supplementary-objects-and-methods/loadfrommemory-method) | Restores the object contents from the global memory. *Windows only.* |
| [SaveToFile](/fine-reader/engine/api-reference/supplementary-objects-and-methods/savetofile-method) | Saves the object contents into a file on disk. |
| [SaveToMemory](/fine-reader/engine/api-reference/supplementary-objects-and-methods/savetomemory-method) | Saves the object contents into the global memory. *Windows only.* |
## Output parameter
This object is the output parameter of the [CreatePngExtendedParams](/fine-reader/engine/api-reference/engine-object-iengine-interface/creation-methods/createlessobjectgreater-methods) method of the [Engine](/fine-reader/engine/api-reference/engine-object-iengine-interface) object.
## Input parameter
This object is the input parameter of the [WriteToFile](/fine-reader/engine/api-reference/image-related-objects/image/writetofile-method) method of the [Image](/fine-reader/engine/api-reference/image-related-objects/image) object.
## See also
[ImageFileFormatEnum](/fine-reader/engine/api-reference/enumerations/imagefileformatenum)
[Working with Images](/fine-reader/engine/guided-tour/advanced-techniques/working-with-images)
[Working with Properties](/fine-reader/engine/guided-tour/advanced-techniques/programming-aspects/working-with-properties)