VLC Media Player:
1. Open your video on VLC media player.
2. Pause your video to the point for which you need to capture image.
3. On Video menu click Snapshot (Menu bar –> Video –> Snapshot)
4. Your image is saved
5. You can access your image from default store location.
6. To change default storage location go to Menu –> Tools –> Preference
7. Under Preference –> Video –> Video Snapshot section. Change your location.
URL for download if you don't already have the program
www.videolan.org/vlc/