EP1627385A2 - Systeme et procede pour decourager les copies au moyen d'une perte recurrente de quantification - Google Patents

Systeme et procede pour decourager les copies au moyen d'une perte recurrente de quantification

Info

Publication number
EP1627385A2
EP1627385A2 EP04730893A EP04730893A EP1627385A2 EP 1627385 A2 EP1627385 A2 EP 1627385A2 EP 04730893 A EP04730893 A EP 04730893A EP 04730893 A EP04730893 A EP 04730893A EP 1627385 A2 EP1627385 A2 EP 1627385A2
Authority
EP
European Patent Office
Prior art keywords
signal
amount
human perception
perception threshold
level
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP04730893A
Other languages
German (de)
English (en)
Inventor
Wilhelmus F. J. Fontijn
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Koninklijke Philips Electronics NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Koninklijke Philips Electronics NV filed Critical Koninklijke Philips Electronics NV
Publication of EP1627385A2 publication Critical patent/EP1627385A2/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/76—Television signal recording
    • H04N5/91—Television signal processing therefor
    • H04N5/913—Television signal processing therefor for scrambling ; for copy protection
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G11B20/00731—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving a digital rights management system for enforcing a usage restriction
    • G11B20/00818—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving a digital rights management system for enforcing a usage restriction wherein the usage restriction limits the signal quality, e.g. by low-pass filtering of audio signals or by reducing the resolution of video signals
    • G11B20/00826—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving a digital rights management system for enforcing a usage restriction wherein the usage restriction limits the signal quality, e.g. by low-pass filtering of audio signals or by reducing the resolution of video signals wherein a spoiler signal is added to degrade the signal quality
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/76—Television signal recording
    • H04N5/91—Television signal processing therefor
    • H04N5/913—Television signal processing therefor for scrambling ; for copy protection
    • H04N2005/91357—Television signal processing therefor for scrambling ; for copy protection by modifying the video signal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/76—Television signal recording
    • H04N5/91—Television signal processing therefor
    • H04N5/913—Television signal processing therefor for scrambling ; for copy protection
    • H04N2005/91357—Television signal processing therefor for scrambling ; for copy protection by modifying the video signal
    • H04N2005/91385—Television signal processing therefor for scrambling ; for copy protection by modifying the video signal the video frame number being modulated

Definitions

  • the present invention relates to a method and apparatus to prevent copying of a video or audio signal by re-encoding the analog signal. More particularly, the present invention is related to modifying the signal which results in cumulatively more obvious recurring quantization loss in subsequent copies of the signal. Most particularly, the present invention is a method and apparatus for modifying a de-coded signal such that quantization loss is recurring and is not perceptible in the original decoding of the signal but with each subsequent copy of the signal the quantization loss cumulatively degrades the quality of the decoded signal so that the quality of the re-encoded signal is below an acceptable level.
  • the system and method of the present invention modulate and manipulate the actual video or audio content of an analog signal to degrade the quality of any re-encoded signal below an acceptable level.
  • analog video is encoded
  • the signal is sampled and a quantization step transforms the analog signal into discrete values that are compressed and stored digitally.
  • the digital signal is decoded the original analog signal is recreated as best as possible. But, the reproduction is not perfect because there are quantization and compression losses at the encoding side, i.e. the difference between the recreated analog value after decoding and the original analog value. This cannot be prevented because by nature the analog signal is continuous whereas the digital signal is discrete.
  • the copy can be close to the original digital encoding with regard to picture quality. This is due to the fact that through a proper choice of re-encoding parameters, the quantization loss does not recur or is very limited.
  • the system and method of the present invention alter the analog signal slightly after the decoding step so that the quantization loss is made recurring.
  • the re-encoded signal can be degraded enough to be annoying, without these measures being perceived by an observer of the first decoded analog signal.
  • These measures can be applied to any parameter that is quantized, e.g. for video such measures comprise frame rate modulation, block shifting, color and luminance variations.
  • the effectiveness of the present invention does not rely on additional measures either on the recording side or on the display side.
  • the cost of implementation is relatively small. It is a simple scheme that does not rely on the cooperation of any other part of an existing system, i.e., it does not require any changes to other parts of an existing system.
  • FIG. 1 illustrates copying a decoded video signal by re-encoding VGA.
  • FIG. 2 illustrates the location within a PC of an embodiment of the present invention that modifies the VGA to video signal derived from a decoded video signal output by the DVD-ROM of the PC.
  • FIG. 3 illustrates the location within a DVD video recorder (DVD-VR) of an embodiment of the present invention that modifies the VGA to video signal derived from a VGA signal of a decoded video signal output by the DVD-ROM of a PC.
  • DVD-VR DVD video recorder
  • FIG. 4 illustrates copying of a copy using two DVD-VRs that incorporate an embodiment of the present invention.
  • FIG. 5 illustrates frame rate modulation of an output analog signal, according to an embodiment of the present invention.
  • FIG. 6 illustrates adding a noise frame to an output analog signal, according to an embodiment of the present invention.
  • FIG. 7 illustrates making a noise addition in the digital domain, according to an embodiment of the present invention.
  • FIG. 8 illustrates sample re-encoding without measures where the frame rate of the re-encoded signal (b) is matched to the frame rate of the original (a).
  • FIG 9 illustrates a re-encoding with frame rate modulation (b) of an original signal (a).
  • FIG. 10 illustrates a re-encoding with luminance noise (b) added to the original signal (a).
  • the system and method of the present invention introduces recurring losses into a video stream by modulating the frame rate of the analog output of a video replay system.
  • the modulation employed by the present invention is low enough to allow the human brain correct for them, i.e. so they are not noticed by a human observer, while it is sufficient to cause discontinuities in the recorded signal.
  • FIGs. 2 and 3 illustrate copying hardware configurations which when modified to accomplish the method of the present invention are embodiments of the present invention that degrade a copy of a VGA signal derived from a PC's DVD-ROM drive.
  • the signal modification takes place in the PC at location 230 so that there is recurring quantization loss in the output VGA signal and when the VGA->video 210 signal is re-encoded 220 and copied there results a noticeable degradation in the quality of a reproduced signal.
  • FIG. 2 the signal modification, according to a preferred embodiment, takes place in the PC at location 230 so that there is recurring quantization loss in the output VGA signal and when the VGA->video 210 signal is re-encoded 220 and copied there results a noticeable degradation in the quality of a reproduced signal.
  • the signal modification also takes place in the PC at location 340 such that the quantization loss is recurring in the VGA->video 310 signal and re-encoding 320 and copying in the DVD-video recorder (DVD-VR) 330 results in a noticeable degradation in the quality of a reproduced signal.
  • FIG. 4 illustrates copying of a copy using DVD-VRs 400 and 410. The present invention can be incorporated into the DVD-VRs as well.
  • a digital source 510 e.g., a DVD-video file
  • a decoder 520 that decodes the content and calculates raw frames that are converted 530 to an analog signal 540.
  • some of the frames are delayed and some are output early.
  • the result is a frame rate modulation 550 in the resulting analog output 560.
  • the pitch of sound can be modulated.
  • a digital source 610 e.g., a DVD-video file
  • a decoder 620 is input to a decoder 620 that decodes the content and calculates raw frames that are converted 630 to an analog signal 640.
  • a noise frame is generated 650 and superimposed 660 on the frame coming from the AD converter such that each output frame 670 has its own noise frame superimposed.
  • the noise frame can consist of a below threshold luminance modulation.
  • FIG. 7 when the registers used for the storage of digital frames are large enough, the noise addition can take place in the digital domain, before the AD conversion 750 where values can be added below the quantization level 730.
  • Each output frame 760 has noise superimposed.
  • FIGs. 8 and 9 the frame rate of the re-encoded signal 810 matches the frame rate of the original signal 800.
  • FIG. 9 the differences in timing are very slight and are not perceivable by the viewer. The cumulative effect of these slight differences is that the re-encoded signal gets out of sync 910 at a certain point of time with the original 900.
  • an optimal compression scheme uses quantization steps that approximate the human perception threshold 1000. If over half of the value of the quantization step is added, i.e. half of the human perception threshold, then a viewer will not notice the difference. If a copy of this signal is re-encoded the recurring quantization loss makes the difference perceptible 1010.
  • random noise is added to the chrominance signal and has a similar effect.
  • the sensitivity of the human eye to color information is much less than the sensitivity to changes in luminance.
  • Another embodiment introduces recurring quantization losses by modulating the pitch of sound.
  • most lose the ability of absolute hearing meaning that they are no longer able to determine the absolute pitch of a sound but can perceive only the pitch of a sound in relation to the pitch of another sound. Slight changes to the pitch, e.g. 10% of the detection threshold, are not perceived. Cumulative slight changes till they reach 100% of the perception threshold are not perceived if the change is made gradually.
  • Re-encoding will make the quantization loss recurring so that any change in pitch becomes perceptible. This is illustrated in Table 1.
  • parameters that are quantized are modulated such that the actual modulation is not perceived but the effect after re-encoding is perceived.
  • modulate quantized parameters comprising time, color, luminance, pitch and position (pixel, block or picture shifting). The effect is further illustrated in Tables 2 and 3.
  • Table 2 In Table 2, analog values ranging from 0 to 100 (a) are quantized with a step of 1 (b). On the reproduced analog signal a random noise below the quantization step, i.e. perception threshold is superimposed (c). This makes the quantization loss recurring, amplifying the noise (d). This effect is repeated if the copy is copied (e), amplifying the effect (f).

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Computer Security & Cryptography (AREA)
  • Television Signal Processing For Recording (AREA)
  • Signal Processing For Digital Recording And Reproducing (AREA)
  • Compression Or Coding Systems Of Tv Signals (AREA)
  • Signal Processing Not Specific To The Method Of Recording And Reproducing (AREA)
  • Compression, Expansion, Code Conversion, And Decoders (AREA)

Abstract

Selon cette invention, un signal est légèrement altéré après l'étape de décodage de sorte que la perte de quantification devienne récurrente, bien que non évidente à l'oeil d'un observateur du signal décodé. Le signal légèrement altéré est suffisamment dégradé lorsqu'il est codé à nouveau pour provoquer une gêne, sans que les mesures aient été perçues dans le premier signal décodé. L'invention peut être appliquée à un signal numérique décodé si l'espace disponible dans le registre est suffisant ou à un signal analogique après sa conversion de signal analogique en signal numérique.
EP04730893A 2003-05-16 2004-05-03 Systeme et procede pour decourager les copies au moyen d'une perte recurrente de quantification Withdrawn EP1627385A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US47145103P 2003-05-16 2003-05-16
PCT/IB2004/001591 WO2004102951A2 (fr) 2003-05-16 2004-05-03 Systeme et procede pour decourager les copies au moyen d'une perte recurrente de quantification

Publications (1)

Publication Number Publication Date
EP1627385A2 true EP1627385A2 (fr) 2006-02-22

Family

ID=33452447

Family Applications (1)

Application Number Title Priority Date Filing Date
EP04730893A Withdrawn EP1627385A2 (fr) 2003-05-16 2004-05-03 Systeme et procede pour decourager les copies au moyen d'une perte recurrente de quantification

Country Status (5)

Country Link
EP (1) EP1627385A2 (fr)
JP (1) JP2007510319A (fr)
KR (1) KR20060010804A (fr)
CN (1) CN1791919A (fr)
WO (1) WO2004102951A2 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4622558B2 (ja) * 2005-02-07 2011-02-02 ソニー株式会社 符号化装置および方法、プログラム、記録媒体、並びにデータ処理システム
KR101465148B1 (ko) * 2013-02-28 2014-11-26 연세대학교 산학협력단 동영상을 부호화/복호화하기 위한 장치 및 그 방법

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5757910A (en) * 1993-04-06 1998-05-26 Goldstar Co., Ltd. Apparatus for preventing illegal copying of a digital broadcasting signal
JP2982768B2 (ja) * 1997-11-07 1999-11-29 日本電気株式会社 不正複写防止方法および装置
US6137952A (en) * 1998-04-02 2000-10-24 Hewlett-Packard Company Apparatus and method for degrading the quality of unauthorized copies of color images and video sequences
TW538636B (en) * 2000-09-01 2003-06-21 Matsushita Electric Industrial Co Ltd Reproduction equipment, reproduction equipment specifying equipment, reproduction equipment specifying system and methods and recording media for said equipment and system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2004102951A2 *

Also Published As

Publication number Publication date
WO2004102951A3 (fr) 2005-03-31
JP2007510319A (ja) 2007-04-19
CN1791919A (zh) 2006-06-21
KR20060010804A (ko) 2006-02-02
WO2004102951A2 (fr) 2004-11-25

Similar Documents

Publication Publication Date Title
US6809792B1 (en) Spectral watermarking for motion picture image data
CN1144400C (zh) 视频的压缩后隐藏数据的传送
US6760375B2 (en) Method for protection of data decoding according to protection data and first and second apparatus protection data to determine whether main data are decoded in their entirety, partially, or not at all
JP3349704B2 (ja) 十分なネットワーク伝送及び記録能力を備えたビデオ信号をスクランブル化する方法及び装置
US6954856B1 (en) Additional information embedding method, additional information detecting method, additional information embedding apparatus and additional information detecting apparatus
EP1085754B1 (fr) Protection numérique contre la copie vidéo
JPH10503338A (ja) ビデオプラットフォーム及び保護されていないソース素材用の総合的なコピー防止の装置及び方法
CN1258915A (zh) 信息信号的版权保护方法、记录和输出的方法和设备
US6137952A (en) Apparatus and method for degrading the quality of unauthorized copies of color images and video sequences
JP4909274B2 (ja) プロテクトされるコンテンツとは別にコピープロテクション情報を格納する方法と装置
US7092616B2 (en) Method and apparatus for copy protecting video content and producing a reduced quality reproduction of video content for personal use
US7636440B2 (en) Digital watermark with variable location
US20040025024A1 (en) Information processing apparatus and information processing method
WO2004102951A2 (fr) Systeme et procede pour decourager les copies au moyen d'une perte recurrente de quantification
US20070086033A1 (en) Media distribution methods and systems with quality degradation
JP2002191033A (ja) 電子透かし埋め込み装置、および電子透かし埋め込み方法
EP0948203A2 (fr) Méthode pour empêcher la copie non autorisée des images
JPH0746535A (ja) デジタル信号記録装置、デジタル信号再生装置
JP2003348318A (ja) 電子透かし埋め込み装置、電子透かし埋め込み方法および記録媒体の製造方法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20051216

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR

DAX Request for extension of the european patent (deleted)
17Q First examination report despatched

Effective date: 20070608

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20071019