Tweening is the art of generating and placing intermediate or “in between” frames between two existing images — giving the perception that the first evolves smoothly into the second. Also known as frame rate conversion (FRC), tweening can be used to replace damaged or missing frames in a digital video system or can provide motion blur reduction in LCD displays. Sarnoff uses advanced optical flow technology to produce tweened frames, thereby concealing errors or increasing motion smoothness.

Sarnoff’s tweening technology creates a highly accurate motion vector for each pixel in a given pair of frames. Called the optical flow field, this information is used to produce an interpolated frame that can be inserted between a pair of existing frames. In doing so, the frame rate is doubled, allowing the video to run smoothly with high quality while offering error concealment. Sarnoff uses a built-in quality metric that assesses the tweened frame and reduces the visibility of motion boundary artifacts.

Tweening has several useful applications. Continuous frame doubling provides smoother motion in video on mobile phones and other portable devices. On LCD screens, it also effectively conceals missing or damaged input frames in video decoders. By replacing missing or damaged frames with smoothly interpolated frames, picture quality is increased.