determine if file is an image

Question

I am looping through a directory and copying all files. Right now I am doing string.EndsWith checks for ".jpg" or ".png", etc . .

Is there any more elegant way of determining if a file is an image (any image type) without the hacky check like above?

Answer 1

Check the file for a known header. (Info from link also mentioned in this answer)

The first eight bytes of a PNG file always contain the following (decimal) values: 137 80 78 71 13 10 26 10

Answer 2

Check out System.IO.Path.GetExtension

Here is a quick sample.

public static readonly List<string> ImageExtensions = new List<string> { ".JPG", ".JPE", ".BMP", ".GIF", ".PNG" };  private void button_Click(object sender, RoutedEventArgs e) {     var folder = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);     var files = Directory.GetFiles(folder);     foreach(var f in files)     {         if (ImageExtensions.Contains(Path.GetExtension(f).ToUpperInvariant()))         {             // process image         }     } }