Conversion

package ppt;

import com.spire.presentation.FileFormat;
import com.spire.presentation.Presentation;

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

public class ConvertDemo {

    public void convertDemo(String filePath, String convertTo, String resultFileName) throws Exception {
        Presentation presentation = new Presentation();
        presentation.loadFromFile(filePath);
        ConvertFormat(presentation, convertTo,resultFileName);
    }


    private void ConvertFormat(Presentation presentation, String convertTo, String resultFileName) throws Exception {
        switch (convertTo){
            case "PDF":
                presentation.saveToFile(resultFileName+".pdf", FileFormat.PDF);
                break;

            case "HTML":
                presentation.saveToFile(resultFileName+".html",FileFormat.HTML);
                break;

            case "IMAGE":
                BufferedImage[] images = new BufferedImage[presentation.getSlides().getCount()];
                for (int i = 0; i< presentation.getSlides().getCount();i++){
                    images[i] = presentation.getSlides().get(i).saveAsImage();
                }
                if (images != null && images.length > 0){
                    if (images.length == 1){
                        ImageIO.write(images[0],".PNG", new File(resultFileName+".png"));
                    }
                }else {
                    for (int j = 0; j < images.length;j++){
                        String fileName = String.format("image-{0}.png",j);
                        ImageIO.write(images[j],".PNG",new File(fileName));
                    }
                }
                break;

            case "XPS":
                presentation.saveToFile(resultFileName+".xps",FileFormat.XPS);
                break;

            case "TIFF":
                presentation.saveToFile(resultFileName+".tiff",FileFormat.TIFF);
                break;
        }
    }
}

using Spire.Presentation;
using System;
using System.Drawing;
using System.Drawing.Imaging;

namespace DemoOnlineCode
{
    class Convertors
    {
        public void demoConvert(string filePath, string format, string resultFileName)
        {
            Presentation presentation = new Presentation();
            presentation.LoadFromFile(filePath);
            ConvertFormat(presentation,format,resultFileName);
        }
        private static void ConvertFormat(Presentation presentation, string format, string resultFileName)
        {
            switch (format)
            {
                case "PDF":
                    presentation.SaveToFile(resultFileName + ".PDF", FileFormat.PDF);
                    break;

                case "HTML":
                    presentation.SaveToFile(resultFileName + ".html", FileFormat.Html);
                    break;

                case "IMAGE":
                    Image[] images = new Image[presentation.Slides.Count];
                    for (int i = 0; i < presentation.Slides.Count;i++)
                    {
                        images[i] = presentation.Slides[i].SaveAsImage();
                    }
                    if (images != null && images.Length > 0)
                    {
                        if (images.Length == 1)
                        {
                            images[0].Save(resultFileName + ".bmp", System.Drawing.Imaging.ImageFormat.Bmp);
                        }
                        else
                        {
                            for (int i = 0; i < images.Length; i++)
                            {
                                string fileName = string.Format("{0}-Image-{1}.png", resultFileName, i);
                                images[i].Save(fileName, ImageFormat.Png);
                            }
                        }
                    }
                        break;

                case "XPS":
                    presentation.SaveToFile(resultFileName + ".xps", FileFormat.XPS);
                    break;

                case "TIFF":
                    Image[] images2 = new Image[presentation.Slides.Count];
                    if (images2 != null && images2.Length > 0)
                    {
                        for (int i = 0; i < presentation.Slides.Count; i++)
                        {
                            images2[i] = presentation.Slides[i].SaveAsImage();
                        }
                            JoinTiffImages(images2,resultFileName+ ".tiff", EncoderValue.CompressionLZW);
                    }                                                      
                    break;            
            }
        }

        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 = null;
            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++;
            }
        }

    }
}