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)? [英] How to convert a XPS file to an image in high quality (rather than blurry low resolution)?

问题描述

我正在尝试使用 WPF 转换 XPS.

I'm trying to convert an XPS with WPF.

想法是这些图像可以用 silverlight 4 加载，为此我使用以下代码:

The idea is that these images can be loaded with silverlight 4, for this I am using the following code:

 // 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/ 一个转换 XPS 的项目文档.效果很好！但问题是图像分辨率低且模糊.我研究并发现了 RenderTargetBitmap 并在此页面上找到:http://www.codeproject.com/Questions/213737/Render-目标位图质量问题

This code is taken from http://xpsreader.codeplex.com/ a project to convert an XPS document. works great! But the problem is that the image is low resolution and blurry. I researched and found that RenderTargetBitmap and find on this page: http://www.codeproject.com/Questions/213737/Render-target-bitmap-quality-issues

这里的问题是你没有使用硬件 RenderTargetBitmap 渲染.

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

One solution is to use DirectX with WPF to do this, but have not found any clear example to show me the right way to do it.

我很欣赏建议.提前致谢.

I appreciate suggestions. Thanks in advance.

更新:我附上了 XPS 文档，我正在尝试转换图像请下载test.xps

推荐答案

我在这篇文章和许多其他文章中看到，人们在将 DocumentPage 转换为 Image 并将其保存在 HDD 上时遇到问题.此方法从文档查看器中获取所有页面并将它们作为 jpg 图像保存在硬盘上.

I saw in this post and in many others that peoples have problems with conversion of DocumentPage to Image and saving it on HDD. This method took all pages from document viewer and save them on HDD as jpg images.

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();
                }
            }
        }
    }

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