pdf转图片，结果图片会变小

//将PDF文档转换为图片的方法



        ///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aImageFormat.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(stringpdfInputPath,string imageOutputPath,



            string imageName, intstartPageNum, int endPageNum, ImageFormat imageFormat, doubleresolution)



        {



           Acrobat.CAcroPDDoc pdfDoc =null;



           Acrobat.CAcroPDPage pdfPage =null;



           Acrobat.CAcroRect pdfRect =null;



           Acrobat.CAcroPoint pdfPoint =null;



            // Create the document (Can only create the AcroExch.PDDocobject using late-binding)



            // Note using VisualBasic helper functions, have to addreference to DLL



           pdfDoc = (Acrobat.CAcroPDDoc)Microsoft.VisualBasic.Interaction.CreateObject("AcroExch.PDDoc","");



            // validateparameter



            if (!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.Bmp; }



            if (resolution <= 0) { resolution =1; }



            // start to convert each page



            for (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, betterfor us to scale in .NET



               // than Acrobat as it would greek out smalltext



               pdfPage.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) + i.ToString() +"." +imageFormat.ToString(), imageFormat);



                   pdfBitmap.Dispose();



               }



               // Application.DoEvents();



            }



           pdfDoc.Close();



            Marshal.ReleaseComObject(pdfPage);



            Marshal.ReleaseComObject(pdfRect);



            Marshal.ReleaseComObject(pdfDoc);



            Marshal.ReleaseComObject(pdfPoint);



        }



 

补充：.NET技术 ,  C#

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