A C# console program that creates square 150x150 thumbnails for all the images in a given folder, preserving the directory structure

Thumbinate.cs

using System;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Threading.Tasks;

namespace Thumbinate
{
    class Program
    {
        static int Main(string[] args)
        {
            var sw = new Stopwatch();
            sw.Start();
            Console.WriteLine("Thumbinate started at {0:yyyy-MM-dd HH:mm:ss.ffff}", DateTime.Now);
            try
            {
                return Run(args);
            }
            catch (Exception ex)
            {
                Console.Error.WriteLine(ex.ToString());
                return 1;
            }
            finally
            {
                sw.Stop();
                Console.WriteLine("Thumbinate finished. Elapsed time: {0}", sw.ElapsedMilliseconds);
            }
        }

        static int Run(string[] args)
        {
            if (args.Length < 2) return Syntax();
            if (!Directory.Exists(args[0])) return Syntax();
            var source = new DirectoryInfo(args[0]);
            var target = Directory.Exists(args[1]) ? new DirectoryInfo(args[1]) :
                                                     Directory.CreateDirectory(args[1]);
            var source_len = source.FullName.Length;


            var files = source.GetFiles("*.jpg", SearchOption.AllDirectories);

            foreach (var file in files)
            {
                try
                {
                    var dest_folder = Path.Combine(target.FullName, file.DirectoryName.Substring(source_len).TrimStart('\\'));
                    if (!Directory.Exists(dest_folder))
                    {
                        Console.WriteLine("Creating folder {0}", dest_folder);
                        Directory.CreateDirectory(dest_folder);
                    }
                    var destination = Path.Combine(dest_folder, file.Name);
                    if (!File.Exists(destination))
                    {
                        using (var bitmap = new Bitmap(file.FullName))
                        {
                            int newWidth = 150, newHeight = 150;
                            int offsetWidth = 0, offsetHeight = 0;
                            if (bitmap.Height < bitmap.Width)
                            {
                                newWidth = (int)((double)bitmap.Width * 150d / (double)bitmap.Height);
                                offsetWidth = (newWidth - 150) / 2;
                            }
                            else
                            {
                                newHeight = (int)((double)bitmap.Height * 150d / (double)bitmap.Width);
                                offsetHeight = (newHeight - 150) / 2;
                            }
                            var cropRect = new Rectangle(offsetWidth, offsetHeight, 150, 150);
                            using (var new_bitmap = new Bitmap(bitmap, newWidth, newHeight))
                            {
                                var cloned = new_bitmap.Clone(cropRect, bitmap.PixelFormat);
                                cloned.Save(destination);
                                cloned.Dispose();
                            }
                        }
                    }
                }
                catch (Exception ex)
                {
                    Console.Error.WriteLine("{0}:: {1}", file.FullName, ex.Message);
                }
            }
            return 0;
        }

        static int Syntax()
        {
            Console.Error.WriteLine("Invalid arguments.\r\nSyntax: Thumbinate source_folder target_folder");
            return 1;
        }
    }
}