PDF转图片工具实现

一、安装

sudo yum install poppler-utils
pdftoppm -v
pdftoppm -png -r 300 a.pdf /tmp/page

运行效果：

PDF转图片工具 - 在线PDF转PNG/JPG/TIFF转换器 | 免费在线工具

后台实现：

using System.Diagnostics;
using System.IO.Compression;namespace SaaS.OfficialWebSite.Web.Utils
{public class PdfTopPmService{private ILogger<PdfTopPmService> _logger;public PdfTopPmService(ILogger<PdfTopPmService> logger){_logger = logger;}public async Task<MemoryStream> ConvertToImagesAsync(MemoryStream pdfStream){// 临时保存PDF文件（仅用于转换过程）var tempPdfPath = Path.GetTempFileName();using (var fileStream = new FileStream(tempPdfPath, FileMode.Create)){pdfStream.Position = 0;await pdfStream.CopyToAsync(fileStream);fileStream.Flush();}// 使用pdftoppm转换PDF为图片var outputFiles = ConvertPdfToImages(tempPdfPath);// 创建ZIP文件（内存流）var zipStream = new MemoryStream();using (var archive = new ZipArchive(zipStream, ZipArchiveMode.Create, true)){foreach (var imagePath in outputFiles){var entry = archive.CreateEntry(Path.GetFileName(imagePath));using (var entryStream = entry.Open()){using (var imageStream = System.IO.File.OpenRead(imagePath)){await imageStream.CopyToAsync(entryStream);}}// 删除临时图片文件System.IO.File.Delete(imagePath);}}// 删除临时PDF文件System.IO.File.Delete(tempPdfPath);return zipStream;}private List<string> ConvertPdfToImages(string pdfPath){var outputFiles = new List<string>();var outputPattern = Path.Combine(Path.GetTempPath(), "page");// 使用pdftoppm命令行工具转换PDFvar process = new Process{StartInfo = new ProcessStartInfo{FileName = "pdftoppm",Arguments = $"-png -r 300 {pdfPath} {outputPattern}",UseShellExecute = false,RedirectStandardOutput = true,CreateNoWindow = true}};process.Start();process.WaitForExit();// 获取生成的图片文件var tempFiles = Directory.GetFiles(Path.GetTempPath(), "page-*.png");outputFiles.AddRange(tempFiles);return outputFiles;}}
}