using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using PowerPoint = Microsoft.Office.Interop.PowerPoint;
using Office = Microsoft.Office.Core;

namespace VSTO
{
    public partial class ThisAddIn
    {
        private void ThisAddIn_Startup(object sender, System.EventArgs e)
        {
            //Create empty presentation
            PowerPoint.Presentation ppt = this.Application.Presentations.Add();

            //Add a blank slide
            PowerPoint.Slide slide = ppt.Slides.Add(1, PowerPoint.PpSlideLayout.ppLayoutBlank);

            //Get the master
            PowerPoint.Master master = ppt.SlideMaster;

            //Insert an image to slide master
            master.Shapes.AddPicture("../../image.gif", Office.MsoTriState.msoTriStateMixed, Office.MsoTriState.msoTriStateMixed, 700, 50, 247, 70);

            //Add a blank slide
            ppt.Slides.Add(1, PowerPoint.PpSlideLayout.ppLayoutBlank);

            //Save the file
            ppt.SaveAs("MasterImage.pptx");
        }

        private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
        {
        }

        #region VSTO generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InternalStartup()
        {
            this.Startup += new System.EventHandler(ThisAddIn_Startup);
            this.Shutdown += new System.EventHandler(ThisAddIn_Shutdown);
        }
        
        #endregion
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Spire.Presentation;
using System.Drawing;
using System.IO;
using Spire.Presentation.Drawing;

namespace Spire.Presentation
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create presentation
            Presentation ppt = new Presentation();

            //Get the slide
            ISlide slide = ppt.Slides[0];

            //Get the master 
            IMasterSlide master = ppt.Masters[0];

            //Insert an image to slide master
            string imageFile = "../../image.gif";           
            IEmbedImage image = master.Shapes.AppendEmbedImage(ShapeType.Rectangle, imageFile, new Rectangle(450,50,247,70));
            image.Line.FillFormat.FillType = FillFormatType.None;
            
            //Add a blank slide
            ppt.Slides.Append();

            //Save and Launch
            ppt.SaveToFile("MasterImage.pptx", FileFormat.Pptx2010);
            System.Diagnostics.Process.Start("MasterImage.pptx");
            
        }
    }
}