net3.1 pdf转图片目前只有两种
Acrobat.dll
要准备的:下载Adobe Acrobat Professional 9
添加引用:Microsoft.CSharp.dll,Acrobat.dll 和Microsoft.VisualBasic.dll
/// <summary>
/// 将PDF文档转换为图片的方法,你可以像这样调用该方法:ConvertPDF2Image("F:\\A.pdf", "F:\\", "A", 0, 0, null, 0);
/// 因为大多数的参数都有默认值,startPageNum默认值为1,endPageNum默认值为总页数,
/// imageFormat默认值为ImageFormat.Jpeg,resolution默认值为1
/// </summary>
/// <param name="pdfInputPath">PDF文件路径</param>
/// <param name="imageOutputPath">图片输出路径</param>
/// <param name="imageName">图片的名字,不需要带扩展名</param>
/// <param name="startPageNum">从PDF文档的第几页开始转换,默认值为1</param>
/// <param name="endPageNum">从PDF文档的第几页开始停止转换,默认值为PDF总页数</param>
/// <param name="imageFormat">设置所需图片格式</param>
/// <param name="resolution">设置图片的分辨率,数字越大越清晰,默认值为1</param>
public static void ConvertPDF2Image(string pdfInputPath, string imageOutputPath,
string imageName, int startPageNum, int endPageNum, ImageFormat imageFormat, double resolution)
{Acrobat.CAcroPDDoc pdfDoc = null;Acrobat.CAcroPDPage pdfPage = null;Acrobat.CAcroRect pdfRect = null;Acrobat.CAcroPoint pdfPoint = null;// Create the document (Can only create the AcroExch.PDDoc object using late-binding)// Note using VisualBasic helper functions, have to add reference to DLLpdfDoc = (Acrobat.CAcroPDDoc)Microsoft.VisualBasic.Interaction.CreateObject("AcroExch.PDDoc", "");// validate parameterif (!pdfDoc.Open(pdfInputPath)) { throw new FileNotFoundException(); }if (!Directory.Exists(imageOutputPath)) { Directory.CreateDirectory(imageOutputPath); }if (startPageNum <= 0) { startPageNum = 1; } if (endPageNum > pdfDoc.GetNumPages() || endPageNum <= 0) { endPageNum = pdfDoc.GetNumPages(); } if (startPageNum > endPageNum) { int tempPageNum = startPageNum; startPageNum = endPageNum; endPageNum = startPageNum; }if (imageFormat == null) { imageFormat = ImageFormat.Jpeg; }if (resolution <= 0) { resolution = 1; }// start to convert each pagefor (int i = startPageNum; i <= endPageNum; i++){pdfPage = (Acrobat.CAcroPDPage)pdfDoc.AcquirePage(i - 1);pdfPoint = (Acrobat.CAcroPoint)pdfPage.GetSize();pdfRect = (Acrobat.CAcroRect)Microsoft.VisualBasic.Interaction.CreateObject("AcroExch.Rect", "");int imgWidth = (int)((double)pdfPoint.x * resolution);int imgHeight = (int)((double)pdfPoint.y * resolution);pdfRect.Left = 0;pdfRect.right = (short)imgWidth;pdfRect.Top = 0;pdfRect.bottom = (short)imgHeight;// Render to clipboard, scaled by 100 percent (ie. original size)// Even though we want a smaller image, better for us to scale in .NET// than Acrobat as it would greek out small textpdfPage.CopyToClipboard(pdfRect, 0, 0, (short)(100 * resolution));IDataObject clipboardData = Clipboard.GetDataObject();if (clipboardData.GetDataPresent(DataFormats.Bitmap)){Bitmap pdfBitmap = (Bitmap)clipboardData.GetData(DataFormats.Bitmap);pdfBitmap.Save(Path.Combine(imageOutputPath, imageName) + ".jpg", imageFormat);pdfBitmap.Dispose();}}pdfDoc.Close();Marshal.ReleaseComObject(pdfPage);Marshal.ReleaseComObject(pdfRect);Marshal.ReleaseComObject(pdfDoc);Marshal.ReleaseComObject(pdfPoint);
}
注意:转换速度、图片质量都还不错,但是无法跨平台使用。
Ghostscript.dll 功能很强大,也能跨平台,但是必须安装 gs10031w64.exe,请加大酌情使用
https://download.csdn.net/download/zuoming120/90575414?spm=1001.2014.3001.5501 这个是资源包
net8 有两种产品
1 Docnet.Core
https://download.csdn.net/download/zuoming120/90575430 这个是我的测试demo
有些时候图片清晰度不够。但是可用
2 itext7.pdfimage
下载 https://github.com/thombrink/itext7.pdfimage
新建core8项目,安装itext7和system.drawing.common
修改 imageListener下有不安全的代码
unsafe{for (int y = 0; y < image.Height; y++){byte* ptrMask = (byte*)bitsMask.Scan0 + y * bitsMask.Stride;byte* ptrInput = (byte*)bitsInput.Scan0 + y * bitsInput.Stride;byte* ptrOutput = (byte*)bitsOutput.Scan0 + y * bitsOutput.Stride;for (int x = 0; x < image.Width; x++){ptrOutput[4 * x] = ptrInput[4 * x]; // blueptrOutput[4 * x + 1] = ptrInput[4 * x + 1]; // greenptrOutput[4 * x + 2] = ptrInput[4 * x + 2]; // redptrOutput[4 * x + 3] = ptrMask[4 * x]; // alpha}}}
改成
// 遍历每一行
for (int y = 0; y < image.Height; y++)
{ // 计算每行的起始字节位置 int scanOffsetInput = y * bitsInput.Stride; int scanOffsetMask = y * bitsMask.Stride; int scanOffsetOutput = y * bitsOutput.Stride; // 获取当前行的字节数组 byte[] scanlineInput = new byte[bitsInput.Stride]; byte[] scanlineMask = new byte[bitsMask.Stride];byte[] scanlineOutput = new byte[bitsOutput.Stride];Marshal.Copy(bitsInput.Scan0 + scanOffsetInput, scanlineInput, 0, scanlineInput.Length); Marshal.Copy(bitsMask.Scan0 + scanOffsetMask, scanlineMask, 0, scanlineMask.Length); // 遍历每一列(或每一像素) for (int x = 0; x < image.Width; x++) { // 计算当前像素在字节数组中的位置(基于每个像素4个字节) int pixelOffsetInput = x * 4; int pixelOffsetMask = x * 4; int pixelOffsetOutput = x * 4; // 读取输入图像的RGB值 byte blue = scanlineInput[pixelOffsetInput]; byte green = scanlineInput[pixelOffsetInput + 1]; byte red = scanlineInput[pixelOffsetInput + 2]; // 读取遮罩图像的alpha值 byte alpha = scanlineMask[pixelOffsetMask]; // 将值写入输出图像的对应位置 scanlineOutput[pixelOffsetOutput] = blue; scanlineOutput[pixelOffsetOutput + 1] = green; scanlineOutput[pixelOffsetOutput + 2] = red; scanlineOutput[pixelOffsetOutput + 3] = alpha; } // 将处理过的行复制回输出图像的BitmapData中 Marshal.Copy(scanlineOutput, 0, bitsOutput.Scan0 + scanOffsetOutput, scanlineOutput.Length);
}
然后运行两个demo,就可以了,切记必须是net8项目