Export images from Word or Excel file to separate pdf files.

MsOfficeImagesToPdf.cs

using System;
using System.IO;
using System.Linq;
using Excel = Microsoft.Office.Interop.Excel;
using Word = Microsoft.Office.Interop.Word;

namespace MsOfficeImagesToPdf
{
    class Converter : IDisposable
    {
        Word.Application word = new Word.Application();
        Excel.Application excel = new Excel.Application();
        string filename;
        int counter;

        string GetNextFilename()
        {
            return Path.ChangeExtension($"{Path.GetFileNameWithoutExtension(filename)} pic{counter++:D3}", "pdf");
        }

        void Save(float width, float height)
        {
            var newDoc = word.Documents.Add();
            var coef = width > 482 ? 17 * 28.3464567f / width : 1;
            width *= coef;
            height *= coef;
            try
            {
                var range = newDoc.Range();
                var page = range.PageSetup;
                page.BottomMargin = 0;
                page.TopMargin = 0;
                page.LeftMargin = 0;
                page.RightMargin = 0;
                page.PageWidth = width;
                page.PageHeight = height;
                range.Paste();

                if (range.InlineShapes.Count > 0)
                    range.InlineShapes[1].ConvertToShape();

                range.ShapeRange.Top = 0;
                range.ShapeRange.Left = 0;
                range.ShapeRange.Width = width;
                range.ShapeRange.Height = height;

                var name = GetNextFilename();
                Console.WriteLine($"{name} - {width}x{height}");
                newDoc.SaveAs(Path.Combine(Environment.CurrentDirectory, name), Word.WdSaveFormat.wdFormatPDF);
            }
            finally
            {
                newDoc.Close(Word.WdSaveOptions.wdDoNotSaveChanges);
            }
        }

        void ProcessWordDoc(string filename)
        {
            var doc = word.Documents.Open(filename, ReadOnly: true);
            var shapes = doc.InlineShapes.OfType<Word.InlineShape>().Select(s => s.ConvertToShape());
            foreach (var shape in doc.Shapes.OfType<Word.Shape>().Concat(shapes))
            {
                shape.Select();
                word.Selection.Copy();
                Save(shape.Width, shape.Height);
            }
            doc.Close(Word.WdSaveOptions.wdDoNotSaveChanges);
        }

        void ProcessExcelBook(string filename)
        {
            var book = excel.Workbooks.Open(filename, ReadOnly: true);
            foreach (var sheet in book.Worksheets.OfType<Excel.Worksheet>())
            {
                foreach (var shape in sheet.Shapes.OfType<Excel.Shape>())
                {
                    shape.CopyPicture();
                    Save(shape.Width, shape.Height);
                }
            }
            book.Close(Excel.XlSaveAction.xlDoNotSaveChanges);
        }

        public void Dispose()
        {
            excel.Quit();
            word.Quit();
        }

        public void Convert(string filename)
        {
            this.filename = filename;
            this.counter = 1;

            switch (Path.GetExtension(filename))
            {
            case ".doc":
            case ".docx":
                ProcessWordDoc(filename);
                break;
            case ".xls":
            case ".xlsx":
                ProcessExcelBook(filename);
                break;
            }
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            using (var converter = new Converter())
            {
                converter.Convert(Path.Combine(Environment.CurrentDirectory, args[0]));
            }
        }
    }
}