动态CPDF图像质量损失

我们正在使用一种叫 DynamicPDF 从数据库的动态数据中动态生成PDF。他们的文档说,他们的软件保持了图像字节的完整性,并且没有做任何更改。尽管如此,我们观察到我们添加的图像在生成的PDF输出上似乎有质量损失(至少是这样)。所以我的问题是,我需要如何处理dynamicpdf API,以确保图像质量输出等于或接近我输入的内容?

我们正在使用版本5.1.2 build 13650,下面是用于添加图像的代码。

private void plcImageMain_LaidOut(object sender, PlaceHolderLaidOutEventArgs e)
{
 if (e.LayoutWriter.RecordSets.Current.HasData)
 {
         string productId = e.LayoutWriter.RecordSets.Current["ProductId"].ToString();
         string imgUrl = base.SetImageUrlParams(e.LayoutWriter.RecordSets.Current["ImageUrl"] as string, e.ContentArea.Width, e.ContentArea.Height);

         System.Drawing.Bitmap bm = base.GetBitmap(imgUrl);

         ceTe.DynamicPDF.PageElements.Image img = new ceTe.DynamicPDF.PageElements.Image(bm, 0, 0);
         img.Height = e.ContentArea.Height;
         img.Width = e.ContentArea.Width;
         e.ContentArea.Add(img);
 }
}

/// <summary>
/// Gets a bitmap from the requested image url
/// </summary>
/// <param name="imgCtrl"></param>
/// <param name="imgUrl"></param>
protected System.Drawing.Bitmap GetBitmap(string imgUrl)
{
 // TODO: Add some validation to ensure the url is an image.
 System.Net.WebRequest httpRequest = System.Net.HttpWebRequest.Create(imgUrl);

 using (System.Net.HttpWebResponse httpResponse = httpRequest.GetResponse() as System.Net.HttpWebResponse)
 using (Stream imgStream = httpResponse.GetResponseStream())
 {
    System.Drawing.Bitmap bm = System.Drawing.Bitmap.FromStream(imgStream) as System.Drawing.Bitmap;
    return bm;
 }
}

[编辑]

Here 是前后截图。

[编辑]

使用getimage编码(为什么这么慢?)

protected ceTe.DynamicPDF.Imaging.ImageData GetImageData(string imgUrl)
{
   ImageData imgData = null;
   using (System.Net.WebClient wc = new System.Net.WebClient())
   {
     imgData = ImageData.GetImage(wc.DownloadData(imgUrl));
   }
  return imgData;
}

GetImageData ("http://s7d2.scene7.com/is/image/SwissArmy/cm_vm_53900E--111mm_sol_front_a?fmt=jpeg&wid=400&hei=640");