The Virtual studio System technique can make use of computer creating dummy properties and scenes and it compose those stuffs and foreground signals come from camera in studios.

虚拟演播室技术是利用计算机虚拟生成演播室内的道具和布景并将其与摄像机输出的前景信号合成。

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Parallax scrolling involves the background image moving slower than the content in the foreground, creating an illusion of depth and immersion. Image credits: squarespace.

视差滚动使背景图像比前景的内容移动得更慢，继而产生深度和沉浸的错觉。

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Magisto will soon offer even more sophisticated effects like morphing between faces and creating a 3D effect by manipulating the background and foreground of integrated images.

ENGADGET: Magisto adds still photos to its AI video editing witchery (video)