Get ImageFormat from File Extension

Question

Is there quick way to get the ImageFormat object associated to a particular file extension? I'm looking for quicker than string comparisons for each format.

Answer 1

Here's some old code I found that should do the trick:

 var inputSource = "mypic.png";  var imgInput = System.Drawing.Image.FromFile(inputSource);  var thisFormat = imgInput.RawFormat; 

This requires actually opening and testing the image--the file extension is ignored. Assuming you are opening the file anyway, this is much more robust than trusting a file extension.

If you aren't opening the files, there's nothing "quicker" (in a performance sense) than a string comparison--certainly not calling into the OS to get file extension mappings.