Convert XPS to PNG using C++

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Aspose.Page C++ XPS to PNG converter allows to convert XPS document to PNG image on Windows and Linux.
It is necessary to do several steps in order to perform XPS to PNG conversion:

  1. Initialize an input stream for input XPS document.
  2. Create an instance of XpsDocument from created earlier input stream.
  3. Specify SmoothingModeResolution and other options of PngSaveOptions.
  4. Create an instance of ImageDevice.
  5. Save XPS document as image with PNG save options to an array of arrays of bytes. One array of bytes for one page of input document.
  6. Save resulting 2-dimensional arrays of bytes to PNG files creating for every bytes array a new file output stream.


Following code snippet shows how to convert XPS to PNG files in C++:

// For complete examples and data files, please go to https://github.com/aspose-page/Aspose.Page-for-C
// The path to the documents directory.
string dataDir = RunExamples.GetDataDir_WorkingWithDocumentConversion();
// Input file
string inputFileName = dataDir + "input.xps";
//Outut file 
string outputFileName = dataDir + "XPStoImage_out.png";
// Initialize XPS input stream
using (Stream xpsStream = File.Open(inputFileName, FileMode.Open, FileAccess.Read))
{
    // Load XPS document form the stream
    XpsDocument document = new XpsDocument(xpsStream, new XpsLoadOptions());
    // or load XPS document directly from file. No xpsStream is needed then.
    // XpsDocument document = new XpsDocument(inputFileName, new XpsLoadOptions());

    // Initialize options object with necessary parameters.
    PngSaveOptions options = new PngSaveOptions()
    {
        SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality,
        Resolution = 300,
        PageNumbers = new int[] { 1, 2, 6 }
    };

    // Create rendering device for image
    ImageDevice device = new ImageDevice();

    document.Save(device, options);

    // Iterate through document partitions (fixed documents, in XPS terms)
    for (int i = 0; i < device.Result.Length; i++)
        // Iterate through partition pages
        for (int j = 0; j < device.Result[i].Length; j++)
        {
            // Initialize image output stream
            using (Stream imageStream = System.IO.File.Open(Path.GetDirectoryName(outputFileName) +
                Path.GetFileNameWithoutExtension(outputFileName) + "_" + (i + 1) + "_" + (j + 1) +
                Path.GetExtension(outputFileName), System.IO.FileMode.Create, System.IO.FileAccess.Write))
                // Write image
                imageStream.Write(device.Result[i][j], 0, device.Result[i][j].Length);
        }
}

Let’s consider PngSaveOptions. Using this class we can assign different conversion parameters while converting XPS to PNG.

  • SmoothingMode assigns a degree of smoothing for lines, curves and edges of filled areas, may be AntiAlias, HighQuality, HighSpeed and Default (none). Default value is HighQuality.
  • Resolution controls resolution of resulting image. Default value is 96.
  • TextRenderingHint assigns quality of text rendering, may be AntiAlias, AntiAliasGridFit, ClearTypeGridFit, SingleBitPerPixel, SingleBitPerPixelGridFit, SystemDefault. Default value in XPS to PNG conversion is AntiAliasGridFit.
  • InterpolationMode defines algorithm that is used when scaling or/and rotating image, may be Bicubic, Bilinear, High, HighQualityBicubic, HighQualityBilinear, Low, NearestNeighbor and Default. Default value is HighQualityBicubic.
  • PageNumbers represents an array of numbers of pages which will be saved to PNG.