How to remove watermarks?

You know, the annoying icons left on video's after being made via certain programs?I'd like to just remove them while leaving the image intact.

vitually impossible with video.

There are some softwares can remove some simple watermark..Of course you can do it via PS.

Replying to #3

PS, explain?

I think it means Photoshop. For images, you can simply erase the watermark I think. But for video, its almost impossible.