Apparent Increase in Noise Level When Television Pictures Are Frame-Repeated

Subjective measurements were made of the apparent increase in noise level which occurs when television pictures are frame-repeated. We show that in all cases of practical interest this increase is small (less than 3 dB), that it is dependent on the type of scanning (greater increases with line-sequential than with line-interlaced scanning), and that it is relatively independent of the picture signal-to-noise ratio. At smaller numbers of repetitions — the region which shows most promise for practical schemes of bandwidth saving — the increase in apparent noise level with increased frame-repetition is most rapid.