Is there hidden watermark can be applied in image like companies logo?
ah, gotcha. It would be nice if we could embed invisible watermarks, but that technology doesn't yet exist... that i know of. The one thing which can be done is in the metadata. It's easy enough to change the copyright info. If you download an image and then view using Bridge, you can see what's in the metadata. Or you can open in Ps and go File>File Info.