Paint.NET image
From Just Solve the File Format Problem
Paint.NET image (or PDN) is the native graphics file format of the Paint.NET image editor for Microsoft Windows.
Identification
Files begin with a signature: the ASCII characters "PDN3
".
Software
- Paint.NET official site (which, confusingly enough, isn't actually at paint.net itself, which belongs to an actual paint company!)
- Lazpaint