Dualities in Computerized Sound Pressure and Advanced Sound Watermarking.


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Dualities in. Advanced Audio Compression and. Advanced Audio Watermarking ... Malvar (2003),
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Dualities in Digital Audio Compression and Digital Audio Watermarking Yi-Wen Liu , Postdoc/Research Engineer, Boys Town National Research Hospital, Omaha, NE Keywords : concealing, gliding point quantization, commotion forming, water filling, channel coding, spread range, composing on filthy paper June 28, 2007

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High constancy AAC encoding at 128 kbps/stereo [Remark] 2 * 44,100 specimens/sec * 16 bits = 1.41 Mbps

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dz dM Masking: Presence of a tone* builds limit in its vicinity** 1.0 Bark ~ 1.3mm on basilar film Spreading capacity takes after the envelope voyaging waves. * Tonal versus commotion masker ** Also check: forward-and in reverse veiling.

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+ Removing veiled segments: Does it accomplish adequate pressure?

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Psycho - acoustics The clamor forming standard: Quantization blunder X (q) [k] – X[k] to be covered Window X (q) [k] X[k] M odified D iscrete C osine T ransform Huffman coding Bit pressing  Quantization x[n] 01001011… Parameters Bit designation

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Band-wise FP quantization: Bit portion minimizes SMR-weighted square mistake.

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Jack and Jill went up the slope to get a bucket of water… R b SMR/6dB N b Fixed-versus variable-rate execution. Imagine a scenario in which R b is fragmentary. negative?

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Image source: Bureau of Engraving and Printing, United States Department of the Treasury http://www.moneyfactory.com/

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Applications of computerized watermarks Copyright insurance Copy security (Philips Research, 2000) Transaction following Prohibiting transfer of pilfered materials (YouTube/Google, 2007) Broadcast observing

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Broadcast checking: the "convenient individuals meter" (By Arbitron Inc., NYSE: ARB) Programs (and plugs) are inserted with acoustical watermarks A wearable gadget Picks up the watermarks Identifies programs System tried in Houston Image source: http://www.arbitron.com/portable_people_meters/home.htm

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signal range watermark Arbitron\'s innovation: Pseudo-irregular watermarks spread underneath concealing sign imprint signal + mark Kirovski & Malvar (2003), "Spread range watermarking of sound signs," IEEE Trans. Signal Processing.

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Noise is Signal and Signal is Noise . B "Assault" N W ENC + DEC B* X Y S B, B*: Bit streams W: Watermark S: Original signal X: Watermarked signal N: Noise Y: Corrupted duplicate of X Information Capacity for discrete-time Gaussian Channel (Shannon 1948): C = ½ log 2 ( 1 + SNR ), bits per test.

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2 n I (U;S) groupings B W: watermark 2 n C documents "Assault" N ENC + DEC B* X Y S: music Communication with irregular "state data" known at the encoder (Gel\'fand & Pinsker, 1980) Theorem: (Costa, 1983. "Composing on messy paper", Cohen & Lapidoth 2002) If N is Gaussian i.i.d. what\'s more, S is ergodic, then limit is as high as though S were additionally known not decoder . C = max p(u,w|s) { I (U;Y) - I (U;S)} = ½ log 2 ( 1 + <W 2 >/<N 2 >)

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= 0 = 1 Image procured from http://cst-www.nrl.navy.mil/cross section/struk/pnma.html Moulin et al. (2005). "Information concealing codes". Q uantization I ndex M odulation (Chen & Wornell, 1999, 2001; Chou et al., 2001) s in s 0 s 1 Δ s: step-size. Should be huge yet not very substantial .

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Similarities and contrasts in light of duality

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We just touched the most superficial layer… What if assault is more brilliant than added substance commotion? Direct scaling & separating Audio pressure Time distorting, pitch moving. Conspiracy assault, affectability assault, … when all is said in done, it\'s an amusement amongst encoder and attacker(s). Encoder\'s leeway: going first; to utilize psychoacoustics without bounds degree. Encoder\'s inconvenience: going first. Attacker(s) can endeavor to alter or even delete watermark.

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MBI Boys Town National Research Hospital Douglas Keefe, Steve Neely Stanford University Music: Julius Smith , Marina Bosi EE: Tom Cover Acknowledgment

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