Convert EPUB to PNG in C#

PNG file format supports lossless image compression that makes it popular among its users. It widely takes to transmit pictures over the network, display photos and graphics on web pages and reserve in cloud storages. With Aspose.HTML for .NET, you can convert EPUB to PNG format programmatically with full control over a wide range of conversion parameters.

In this article, you find information on how to convert EPUB to PNG using ConvertEPUB() methods of the Converter class, and how to apply ImageSaveOptions and ICreateStreamProvider parameters.

Online EPUB Converter

You can check the Aspose.HTML for .NET API functionality and convert EPUB in real-time. Please load an EPUB file from the local file system, select the output format and run the example. In the example, the save options are set by default. You will immediately receive the result as a separate file.

If you want to convert EPUB to PNG programmatically, please see the following C# code examples.

EPUB to PNG by a single line of code

The static methods of the Converter class are primarily used as the easiest way to convert an EPUB file into various formats. You can convert EPUB to PNG in your C# application literally with a single line of code!

// Invoke the ConvertEPUB() method to convert EPUB to PNG
Converter.ConvertEPUB(File.OpenRead(DataDir + "input.epub"), new ImageSaveOptions(), Path.Combine(OutputDir, "convert-with-single-line.png"));

Convert EPUB to PNG

To convert EPUB to PNG, you should follow a few steps:

1. Open an existing EPUB file. In the example, we use the OpenRead() method of System.IO.FileStream class to open and read an EPUB file from the file system at the specified path.
2. Create a new ImageSaveOptions object. By default, the Format property is PNG.
3. Use the ConvertEPUB() method of the Converter class to save EPUB as a PNG image. You need to pass the EPUB file stream, ImageSaveOptions, and output file path to the ConvertEPUB() method for EPUB to PNG conversion.

Please take a look over the following C# code snippet which shows the process of converting EPUB to PNG using Aspose.HTML for .NET.

// Open an existing EPUB file for reading
using var stream = File.OpenRead(DataDir + "input.epub");

// Prepare a path to save the converted file
string savePath = Path.Combine(OutputDir, "input-output.png");

// Create an instance of the ImageSaveOptions class 
var options = new ImageSaveOptions();

// Call the ConvertEPUB() method to convert EPUB to PNG
Converter.ConvertEPUB(stream, options, savePath);

Save Options – ImageSaveOptions Class

Aspose.HTML for .NET allows converting EPUB to PNG using default or custom save options. ImageSaveOptions usage enables you to tune the rendering process. You can specify the page size, margins, CSS media-type, etc.

Property	Description
Compression	Sets Tagged Image File Format (TIFF) Compression. By default, this property is LZW.
CSS	Gets a CssOptions object which is used for configuration of CSS properties processing.
Format	Sets the ImageFormat (JPG, PNG, BMP, TIFF, or GIF). By default, this property is PNG.
BackgroundColor	This property sets the color that will fill the background. By default, this property is Transparent.
PageSetup	This property gets a page setup object and uses it for configuration output page-set.
HorizontalResolution	Sets horizontal resolution for output images in pixels per inch. The default value is 300 dpi.
VerticalResolution	Sets vertical resolution for output images in pixels per inch. The default value is 300 dpi.
UseAntialiasing	This property sets the image rendering quality. Antialiasing is enabled by default.
Text	Gets a TextOptions object which is used for configuration of text rendering.

To learn more about the ImageSaveOptions class, please read the Fine-Tuning Converters article.

Convert EPUB to PNG using ImageSaveOptions

To convert EPUB to PNG with ImageSaveOptions specifying, you should follow a few steps:

1. Open an existing EPUB file.
2. Create a new ImageSaveOptions object and specify save options.
3. Use the ConvertEPUB() method of the Converter class to save EPUB as a PNG image. You need to pass the EPUB file stream, ImageSaveOptions, and output file path to the ConvertEPUB() method to convert EPUB to PNG.

The following C# code snippet shows how to convert EPUB to PNG using custom save options:

// Open an existing EPUB file for reading
using var stream = File.OpenRead(DataDir + "input.epub");

// Prepare a path to save the converted file
string savePath = Path.Combine(OutputDir, "input-options.png");

// Initialize ImageSaveOptions 
var options = new ImageSaveOptions()
{
    UseAntialiasing = true,
    HorizontalResolution = 400,
    VerticalResolution = 400,
    BackgroundColor = System.Drawing.Color.AliceBlue
};            

// Call the ConvertEPUB() method to convert EPUB to PNG
Converter.ConvertEPUB(stream, options, savePath);

The ImageSaveOptions() constructor initializes an instance of the ImageSaveOptions class that is passed to ConvertEPUB() method. The ConvertEPUB() method takes the stream, options, output file path savePath and performs the conversion operation.

In the example, we use:

• BackgroundColor property that specifies the color that the background will be filled in. The default BackgroundColor is Transparent.
• HorizontalResolution and VerticalResolution properties that set horizontal/vertical resolution for output images in pixels per inch. By default, these properties are 300 dpi.
• UseAntialiasing property that sets the rendering quality for this image. This example uses UseAntialiasing = true for quality rendering.

Use UseAntialiasing = true when you want to improve the visual quality of rendered shapes, text, and images in your application, especially when clarity and smooth edges are essential. Enabling antialiasing smooths out jagged edges by blending the colors of pixels around the edges, resulting in a softer, more refined look.

While UseAntialiasing = true provides better visual quality, it can also increase processing time. For applications where rendering speed is a priority, it may be optimal to set UseAntialiasing = false.

You can download the complete examples and data files from GitHub.

Aspose.HTML offers a free online EPUB to PNG Converter that converts EPUB to PNG image with high quality, easy and fast. Just upload, convert your files and get results in a few seconds!