C# PDF转图片（Png/Bmp/Emf/Tiff）

1、下载并安装该类库，在项目程序中添加Spire.Pdf.dll文件

2、（一）PDF转Png【C#】using Spire.Pdf;using System.Drawing;namespace PDFtoImage1{ class Program { static void Main(string[] args) { //初始化一个PdfDocument类实例,并加载PDF文档 PdfDocument doc = new PdfDocument(); doc.LoadFromFile(@"C:\Users\Administrator\Desktop\sample.pdf"); //遍历PDF每一页 for (int i = 0; i < doc.Pages.Count; i++) { //将PDF页转换成Bitmap图形 System.Drawing.Image bmp = doc.SaveAsImage(i); //将Bitmap图形保存为Png格式的图片 string fileName = string.Format("Page-{0}.png", i + 1); bmp.Save(fileName, System.Drawing.Imaging.ImageFormat.Png); } } }}调试运行程序，生成文档。（Spire.PDF支持将PDF文档转换为多种图像格式的文件，可根据需要选择相应的文件格式，这里以Png为例。）

3、（二）PDF转Ti酆璁冻嘌ff【C#】using System;using System.Drawing;using System.Drawing.Imaging;using Spire.Pdf;namespace SavePdfAsTiff{ class Program { static void Main(string[] args) { //创建一个PdfDocument类对象，并加载PDF文档 PdfDocument document = new PdfDocument(); document.LoadFromFile(@"C:\Users\Administrator\Desktop\sample.pdf"); //调用方法SaveAsImage()将PDF文档保存为tiff格式 JoinTiffImages(SaveAsImage(document), "result.tiff", EncoderValue.CompressionLZW); System.Diagnostics.Process.Start("result.tiff"); } //自定义方法SaveAsImage()将PDF文档保存图像文件 private static Image[] SaveAsImage(PdfDocument document) { Image[] images = new Image[document.Pages.Count]; for (int i = 0; i < document.Pages.Count; i++) { images[i] = document.SaveAsImage(i); } return images; } private static ImageCodecInfo GetEncoderInfo(string mimeType) { ImageCodecInfo[] encoders = ImageCodecInfo.GetImageEncoders(); for (int j = 0; j < encoders.Length; j++) { if (encoders[j].MimeType == mimeType) return encoders[j]; } throw new Exception(mimeType + " mime type not found in ImageCodecInfo"); } //自定义JoinTiffImages()方法，使用指定编码器和图像编码器参数将图像从pdf页面保存到tiff图像类型，。 public static void JoinTiffImages(Image[] images, string outFile, EncoderValue compressEncoder) { Encoder enc = Encoder.SaveFlag; EncoderParameters ep = new EncoderParameters(2); ep.Param[0] = new EncoderParameter(enc, (long)EncoderValue.MultiFrame); ep.Param[1] = new EncoderParameter(Encoder.Compression, (long)compressEncoder); Image pages = images[0]; int frame = 0; ImageCodecInfo info = GetEncoderInfo("image/tiff"); foreach (Image img in images) { if (frame == 0) { pages = img; pages.Save(outFile, info, ep); } else { ep.Param[0] = new EncoderParameter(enc, (long)EncoderValue.FrameDimensionPage); pages.SaveAdd(img, ep); } if (frame == images.Length - 1) { ep.Param[0] = new EncoderParameter(enc, (long)EncoderValue.Flush); pages.SaveAdd(ep); } frame++; } } }}

4、（三）转换PDF指定页为图片（PDF转Png、Bmp、Emf）【C#】using Spire.Pdf;using System.Drawing;usi荏鱿胫协ng System.Drawing.Imaging;namespace PDFtoImage{ class Program { static void Main(string[] args) { //实例化一个PdfDocument类对象，并加载PDF文档 PdfDocument doc = new PdfDocument(); doc.LoadFromFile(@"C:\Users\Administrator\Desktop\sample.pdf"); //调用方法SaveAsImage()将PDF第二页保存为Bmp格式 Image bmp = doc.SaveAsImage(1); // //调用另一个SaveAsImage()方法，并将指定页面保存保存为Emf、Png Image emf = doc.SaveAsImage(0, Spire.Pdf.Graphics.PdfImageType.Metafile); Image zoomImg = new Bitmap((int)(emf.Size.Width * 2), (int)(emf.Size.Height * 2)); using (Graphics g = Graphics.FromImage(zoomImg)) { g.ScaleTransform(2.0f, 2.0f); g.DrawImage(emf, new Rectangle(new Point(0, 0), emf.Size), new Rectangle(new Point(0, 0), emf.Size), GraphicsUnit.Pixel); } //命名保存的文件并打开 bmp.Save("convertToBmp.bmp", ImageFormat.Bmp); System.Diagnostics.Process.Start("convertToBmp.bmp"); emf.Save("convertToEmf.emf", ImageFormat.Emf); System.Diagnostics.Process.Start("convertToEmf.emf"); zoomImg.Save("convertToZoom.png", ImageFormat.Png); System.Diagnostics.Process.Start("convertToZoom.png"); } }}