如何将XPS文件转换为高质量的图像(而不是模糊的低分辨率)？

Question

我正在尝试使用WPF转换XPS.

想法是这些图像可以加载silverlight 4,为此我使用以下代码:

 // XPS Document
            XpsDocument xpsDoc = new XpsDocument(xpsFileName, System.IO.FileAccess.Read);
            FixedDocumentSequence docSeq = xpsDoc.GetFixedDocumentSequence();

        // The number of pages
        PageCount = docSeq.References[0].GetDocument(false).Pages.Count;

        DocumentPage sizePage = docSeq.DocumentPaginator.GetPage(0);
        PageHeight = sizePage.Size.Height;
        PageWidth = sizePage.Size.Width;
        // Scale dimensions from 96 dpi to 600 dpi.
        double scale = 300/ 96;

        // Convert a XPS page to a PNG file
        for (int pageNum = 0; pageNum < PageCount; pageNum++)
        {
            DocumentPage docPage = docSeq.DocumentPaginator.GetPage(pageNum);
            BitmapImage bitmap = new BitmapImage();
            RenderTargetBitmap renderTarget =
                new RenderTargetBitmap((int)(scale * (docPage.Size.Height + 1)),
                                                               (int)(scale * (docPage.Size.Height + 1)),
                                                               scale * 96,
                                                               scale * 96, PixelFormats.Pbgra32);
            renderTarget.Render(docPage.Visual);


            PngBitmapEncoder encoder = new PngBitmapEncoder();

            encoder.Frames.Add(BitmapFrame.Create(renderTarget));

            FileStream pageOutStream = new FileStream(name + ".Page" + pageNum + ".png", FileMode.Create, FileAccess.Write);
            encoder.Save(pageOutStream);
            pageOutStream.Close();

此代码取自http://xpsreader.codeplex.com/转换XPS文档的项目.效果很好!但问题是图像分辨率低且模糊.我研究并发现RenderTargetBitmap并在此页面上找到:http: //www.codeproject.com/Questions/213737/Render-target-bitmap-quality-issues

这里的问题是你有没有使用硬件RenderTargetBitmap渲染.

一种解决方案是使用带有WPF的DirectX来执行此操作,但是没有找到任何明确的示例来向我展示正确的方法.

我很感激建议.提前致谢.

更新:我附加了XPS文档,我正在尝试转换图像 请下载test.xps

Answer 1

sourceforge.net上有一个名为xps2img的项目,它将xps转换为图像.它是用C#制作的,还包含源代码.看看这个.它将帮助您实现您想要的.

http://sourceforge.net/projects/xps2img/files/

Answer 2

我在这篇文章以及许多其他文章中看到，人们在将DocumentPage转换为Image并将其保存到HDD时遇到问题。此方法从文档查看器中获取所有页面，并将它们另存为jpg图像在HDD上。

public void SaveDocumentPagesToImages(IDocumentPaginatorSource document, string dirPath)
    {
        if (string.IsNullOrEmpty(dirPath)) return;

        if (dirPath[dirPath.Length - 1] != '\\')
            dirPath += "\\";

        if (!Directory.Exists(dirPath)) return;

        MemoryStream[] streams = null;
        try
        {
            int pageCount = document.DocumentPaginator.PageCount;
            DocumentPage[] pages = new DocumentPage[pageCount];
            for (int i = 0; i < pageCount; i++)
                pages[i] = document.DocumentPaginator.GetPage(i);

            streams = new MemoryStream[pages.Count()];

            for (int i = 0; i < pages.Count(); i++)
            {
                DocumentPage source = pages[i];
                streams[i] = new MemoryStream();

                RenderTargetBitmap renderTarget =
                   new RenderTargetBitmap((int)source.Size.Width,
                                           (int)source.Size.Height,
                                           96, // WPF (Avalon) units are 96dpi based
                                           96,
                                           System.Windows.Media.PixelFormats.Default);

                renderTarget.Render(source.Visual);

                JpegBitmapEncoder encoder = new JpegBitmapEncoder();  // Choose type here ie: JpegBitmapEncoder, etc
                encoder.QualityLevel = 100;
                encoder.Frames.Add(BitmapFrame.Create(renderTarget));

                encoder.Save(streams[i]);

                FileStream file = new FileStream(dirPath + "Page_" + (i+1) + ".jpg", FileMode.CreateNew);
                file.Write(streams[i].GetBuffer(), 0, (int)streams[i].Length);
                file.Close();

                streams[i].Position = 0;
            }
        }
        catch (Exception e1)
        {
            throw e1;
        }
        finally
        {
            if (streams != null)
            {
                foreach (MemoryStream stream in streams)
                {
                    stream.Close();
                    stream.Dispose();
                }
            }
        }
    }