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Mosquito Noise in MPEG-compressed Video: Test Patterns and Metrics



Charles D. Fenimore, John M. Libert, Peter Roitman


Mosquito noise is a time dependent video compression impairment in which the high frequency spatial detail in video images having crisp edges is aliased intermittently. A new synthetic test pattern of moving spirals or circles is described which generates mosquito noise (MN) under Motion Pictures Expert Group (MPEG) compression. The spiral pattern is one of several NIST-developed patterns designed to stress specific features of compression based on motion estimation and quantization. The Spirals pattern has several spirals or circles superimposed on a uniform background. The frames are filtered to avoid interline flicker which may be confounded with MN. Motion of the spirals and changing luminance of the background can be included to reduce the correlation between successive frames. Unexpectedly, even a static pattern of spirals can induce mosquito noise due to the stochastic character of the encoder. We consider metrics which are specific to the impairment being measured. For mosquito noise, we examine two separable detectors: each consists of a temporal (frame-to-frame) computation applied to the output of a spatial impairment detector which is applied to each frame. The two spatial detectors are: FLATS, which detects level 8 x 8-pixel image blocks; and the root-mean-square (RMS) applied to the image differences between original and compressed frames. The test patterns are encoded at low bit rates. We examine the measured mosquito noise as a function of the Group-of-Pictures (GOP) pattern in the MPEG-2 encoding and find the GOP structure defines the periodicities of the MN.
Proceedings Title
Proc. Intl. Soc. for Optical Engineering (SPIE) Conf. on Human Vision and Electronic Imaging V
Conference Dates
January 24-27, 2000
Conference Location
San Jose, CA


digital video compression, flats, mosquito noise, quality metrics , test patterns, time dependent, stochastic process


Fenimore, C. , Libert, J. and Roitman, P. (2000), Mosquito Noise in MPEG-compressed Video: Test Patterns and Metrics, Proc. Intl. Soc. for Optical Engineering (SPIE) Conf. on Human Vision and Electronic Imaging V, San Jose, CA, [online], (Accessed April 15, 2024)
Created December 31, 1999, Updated October 12, 2021