import com.spire.presentation.FileFormat;
import com.spire.presentation.Presentation;
import com.spire.presentation.SlideBackground;
import com.spire.presentation.drawing.*;

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

public class AppplyBgToAllSlides {

    public static void main(String[] args) throws Exception {

        //load a PowerPoint file
        Presentation presentation = new Presentation();
        presentation.loadFromFile("C:\\Users\\Administrator\\Desktop\\input.pptx");

        //get the image data
        BufferedImage bufferedImage = ImageIO.read(new FileInputStream("C:\\Users\\Administrator\\Desktop\\bg.jpg"));
        IImageData imageData = presentation.getImages().append(bufferedImage);

        //loop through the slides
        for (int i = 0; i < presentation.getSlides().getCount() ; i++) {

            //apply the image to the specific slide as background
            SlideBackground background = presentation.getSlides().get(i).getSlideBackground();
            background.setType(BackgroundType.CUSTOM);
            background.getFill().setFillType(FillFormatType.PICTURE);
            background.getFill().getPictureFill().setFillType(PictureFillType.STRETCH);
            background.getFill().getPictureFill().getPicture().setEmbedImage(imageData);
        }

        //save the file
        presentation.saveToFile("output/BackgroundImage.pptx", FileFormat.PPTX_2013);
        presentation.dispose();
    }
}