import com.spire.pdf.FileFormat;
import com.spire.pdf.PdfDocument;
import com.spire.pdf.conversion.PdfStandardsConverter;
import com.spire.pdf.graphics.PdfImageType;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

public class PdfConvertDemo {

    public void pdfConversion(String pdfFile,String convertType) throws IOException {
        String outputFileName = "output";
        PdfDocument pdf=new PdfDocument();
        pdf.loadFromFile(pdfFile);
        PdfStandardsConverter standardsConverter = new PdfStandardsConverter(pdfFile);
        switch (convertType) {
            case "DOCX":
                outputFileName += ".docx";
                pdf.saveToFile(outputFileName, FileFormat.DOCX);
                break;
            case "DOC":
                outputFileName += ".doc";
                pdf.saveToFile(outputFileName, FileFormat.DOC);
                break;
            case "XPS":
                outputFileName += ".xps";
                pdf.saveToFile(outputFileName, FileFormat.XPS);
                break;
            case "XLSX":
                outputFileName += ".xlsx";
                pdf.saveToFile(outputFileName, FileFormat.XLSX);
                break;
            case "POSTSCRIPT":
                outputFileName += ".ps";
                pdf.saveToFile(outputFileName, FileFormat.POSTSCRIPT);
                break;
            case "HTML":
                outputFileName += ".html";
                pdf.saveToFile(outputFileName, FileFormat.HTML);
                break;
            case "IMAGE":
                BufferedImage image=null;
                for (int i = 0; i < pdf.getPages().getCount(); i++) {
                    image= pdf.saveAsImage(i, PdfImageType.Bitmap);
                    ImageIO.write(image,"PNG",new File(outputFileName+i+".png"));
                }
                break;
            case "SVG":
                outputFileName+=".svg";
                pdf.saveToFile(outputFileName, FileFormat.SVG);
                break;
            case "TIFF":
                outputFileName += ".tiff";
                pdf.saveToTiff(outputFileName);
                break;
            case "PDFA1A":
                outputFileName += ".pdf";
                standardsConverter.toPdfA1A(outputFileName);
                break;
            case "PDFA1B":
                outputFileName += ".pdf";
                standardsConverter.toPdfA1B(outputFileName);
                break;
            case "PDFA2A":
                outputFileName += ".pdf";
                standardsConverter.toPdfA2A(outputFileName);
                break;
            case "PDFA2B":
                outputFileName += ".pdf";
                standardsConverter.toPdfA2B(outputFileName);
                break;
            case "PDFA3A":
                outputFileName += ".pdf";
                standardsConverter.toPdfA3A(outputFileName);
                break;
            case "PDFA3B":
                outputFileName += ".pdf";
                standardsConverter.toPdfA3B(outputFileName);
                break;
        }
        pdf.close();
    }
}

using Spire.Pdf;
using Spire.Pdf.Conversion;
using Spire.Pdf.Graphics;
using System;
using System.Drawing;
using System.Drawing.Imaging;

namespace DemoOnlineCode
{
    class PdfConvertDemo
    {
        public void PdfConversions(string pdfFile, string convertType)
        {
            String outputFileName = "output";
            PdfDocument pdf = new PdfDocument();
            pdf.LoadFromFile(pdfFile);
            PdfStandardsConverter standardsConverter = new PdfStandardsConverter(pdfFile);
            switch (convertType)
            {
                case "DOCX":
                    outputFileName += ".docx";
                    pdf.SaveToFile(outputFileName, FileFormat.DOCX);
                    break;
                case "DOC":
                    outputFileName += ".doc";
                    pdf.SaveToFile(outputFileName, FileFormat.DOC);
                    break;
                case "XPS":
                    outputFileName += ".xps";
                    pdf.SaveToFile(outputFileName, FileFormat.XPS);
                    break;
                case "XLSX":
                    outputFileName += ".xlsx";
                    pdf.SaveToFile(outputFileName, FileFormat.XLSX);
                    break;
                case "POSTSCRIPT":
                    outputFileName += ".ps";
                    pdf.SaveToFile(outputFileName, FileFormat.POSTSCRIPT);
                    break;
                case "HTML":
                    outputFileName += ".html";
                    pdf.ConvertOptions.SetPdfToHtmlOptions(true, false, 1, false);
                    pdf.SaveToFile(outputFileName, FileFormat.HTML);
                    break;
                case "IMAGE":
                    Image image = null;
                    for (int i = 0; i < pdf.Pages.Count; i++)
                    {
                        image = pdf.SaveAsImage(i, PdfImageType.Bitmap);
                        image.Save(outputFileName + i + ".png",ImageFormat.Png);
                    }
                    break;
                case "SVG":
                    outputFileName += ".svg";
                    pdf.SaveToFile(outputFileName, FileFormat.SVG);
                    break;
                case "TIFF":
                    outputFileName += ".tiff";
                    JoinTiffImages(SaveAsImage(pdf), outputFileName, EncoderValue.CompressionLZW);
                    break;
                case "PDFA1A":
                    outputFileName += ".pdf";
                    standardsConverter.ToPdfA1A(outputFileName);
                    break;
                case "PDFA1B":
                    outputFileName += ".pdf";
                    standardsConverter.ToPdfA1B(outputFileName);
                    break;
                case "PDFA2A":
                    outputFileName += ".pdf";
                    standardsConverter.ToPdfA2A(outputFileName);
                    break;
                case "PDFA2B":
                    outputFileName += ".pdf";
                    standardsConverter.ToPdfA2B(outputFileName);
                    break;
                case "PDFA3A":
                    outputFileName += ".pdf";
                    standardsConverter.ToPdfA3A(outputFileName);
                    break;
                case "PDFA3B":
                    outputFileName += ".pdf";
                    standardsConverter.ToPdfA3B(outputFileName);
                    break;
            }
            pdf.Close();
        }
        private static Image[] SaveAsImage(PdfDocument document)
        {
            Image[] images = new Image[document.Pages.Count];
            for (int i = 0; i < document.Pages.Count; i++)
            {
                //Use the document.SaveAsImage() method save the pdf as image
                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");
        }
        public static void JoinTiffImages(Image[] images, string outFile, EncoderValue compressEncoder)
        {
            //Use the save encoder
            System.Drawing.Imaging.Encoder enc = System.Drawing.Imaging.Encoder.SaveFlag;
            EncoderParameters ep = new EncoderParameters(2);
            ep.Param[0] = new EncoderParameter(enc, (long)EncoderValue.MultiFrame);
            ep.Param[1] = new EncoderParameter(System.Drawing.Imaging.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;
                    //Save the first frame
                    pages.Save(outFile, info, ep);
                }
                else
                {
                    //Save the intermediate frames
                    ep.Param[0] = new EncoderParameter(enc, (long)EncoderValue.FrameDimensionPage);
                    pages.SaveAdd(img, ep);
                }
                if (frame == images.Length - 1)
                {
                    //Flush and close.
                    ep.Param[0] = new EncoderParameter(enc, (long)EncoderValue.Flush);
                    pages.SaveAdd(ep);
                }
                frame++;
            }
        }
    }
}