The Digital Wetgate: A Third-Generation Noise Reducer

Gerhard Wischermann

This paper describes the development of noise-reduction technology and addresses its applications. First-generation noise reducers using linear filtering techniques such as recursive or transversal filters were designed for removing film grain noise or tape noise of analog VTRs. With the introduction of nonlinear median filtering techniques it became possible to conceal impulse-type noise such as film dust, randomly dispersed film scratches, or FM sparkles. — A third-generation noise reducer now has been developed by BTS. By the use of advanced techniques for error detection and motion adaption it is now possible to conceal large film dirt or fixed vertical film scratches — so-called tramline scratches. A wide range of new features especially designed for film reproduction, such as automatic pulldown and scene-change detection, provide great concealment power in the digital wetgate.

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Published
1996-02
Content type
Information
DOI
10.5594/J04670
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