WO2004014079A1 - Procede et appareil d'insertion et d'extraction de filigrane - Google Patents

Procede et appareil d'insertion et d'extraction de filigrane Download PDF

Info

Publication number
WO2004014079A1
WO2004014079A1 PCT/KR2002/001205 KR0201205W WO2004014079A1 WO 2004014079 A1 WO2004014079 A1 WO 2004014079A1 KR 0201205 W KR0201205 W KR 0201205W WO 2004014079 A1 WO2004014079 A1 WO 2004014079A1
Authority
WO
WIPO (PCT)
Prior art keywords
watermark
image
component
message
embedding
Prior art date
Application number
PCT/KR2002/001205
Other languages
English (en)
Inventor
Chang-Keun Choi
Ik-Seong Bae
Hyun-Tae Kim
Jeong-Hyun Kim
Chang-Ryoul Choi
Je-Chang Jeong
Original Assignee
Sealtronic Technology, Inc.
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 Sealtronic Technology, Inc. filed Critical Sealtronic Technology, Inc.
Priority to PCT/KR2002/001205 priority Critical patent/WO2004014079A1/fr
Priority to AU2002346328A priority patent/AU2002346328A1/en
Publication of WO2004014079A1 publication Critical patent/WO2004014079A1/fr

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T1/00—General purpose image data processing
    • G06T1/0021—Image watermarking
    • G06T1/005—Robust watermarking, e.g. average attack or collusion attack resistant
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T1/00—General purpose image data processing
    • G06T1/0021—Image watermarking
    • G06T1/0028—Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
    • 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
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2201/00—General purpose image data processing
    • G06T2201/005—Image watermarking
    • G06T2201/0065—Extraction of an embedded watermark; Reliable detection
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2201/00—General purpose image data processing
    • G06T2201/005—Image watermarking
    • G06T2201/0083—Image watermarking whereby only watermarked image required at decoder, e.g. source-based, blind, oblivious
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2201/00—General purpose image data processing
    • G06T2201/005—Image watermarking
    • G06T2201/0202—Image watermarking whereby the quality of watermarked images is measured; Measuring quality or performance of watermarking methods; Balancing between quality and robustness
    • 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
    • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G11B20/00884—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving a watermark, i.e. a barely perceptible transformation of the original data which can nevertheless be recognised by an algorithm
    • 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
    • H04N2005/91307—Television signal processing therefor for scrambling ; for copy protection by adding a copy protection signal to the video signal
    • H04N2005/91335—Television signal processing therefor for scrambling ; for copy protection by adding a copy protection signal to the video signal the copy protection signal being a watermark

Definitions

  • the present invention relates to a method for embedding and detecting a self-reference watermark by using the extended M-ary modulation method based on QOS and a finite field sequence resistant to desynchronization attacks, in a watermarking method for protecting a copyright.
  • Watermarking is a technology for protecting a copyright by embedding an imperceptible signal in an image and afterward detecting an embedded watermark from the image, thereby offering a viable alternative for the protection of copyright.
  • Conventional watermarks have been embedded with a type of perceptible logo, but recently other methods for embedding an imperceptible watermark are being studied to overcome a problem caused by watermark deletion and qualitative degradation of an image.
  • the original copyright owner can settle a dispute by embedding the copyrighter's imperceptible watermark and then detecting the embedded watermark.
  • this buyer who is illegally circulating this image can be discovered by detecting the watermark embedded in the circulated image if the original copyrighter sold the image with the watermark embedded. That is, the watermark can be used for protection of the copyright of digital images and prevention of copying data. Because the traditional watermarking method does not use original data, it is impossible for the watermark to be detected with regard to desynchronization attacks, for example, rotation, image scaling, and image aspect ratio change.
  • the present invention is proposed to overcome the aforementioned problems of the prior art.
  • the object of the present invention is to provide a method and a device for protecting a copyright of digital contents by applying a robust watermarking method.
  • another object of the present invention is to provide the robust watermarking method that is resilient to desynchronization attacks and overcomes the problem caused by the conventional watermarking method having a difference between the original data and the watermark-embedded image. Also, another object of the present invention is to provide a watermarking method for resolving problems of a self-reference watermarking method such as low channel capacity and high calculation amount.
  • the method and the device for embedding a watermark to an image is characterized as follows: separating Y component from the image; determining an intensity of embedding the watermark by using the separated Y component; coding the message by using a message and copyrighter key to generate a watermark sequence; and embedding the watermark to the Y component corresponding to an intensity of embedding of watermark and the watermark sequence.
  • a step for determining the intensity of embedding the watermark by using the separated Y component further comprises determining an intensity of embedding the entire watermark by the overall complexity of the image and determining an intensity of embedding the watermark regionally.
  • a step of coding a message by using a message and copyrighter key to generate a watermark sequence further comprises: establishing a finite field sequence and the message about synchronization information content as a two-dimensional ("2-D") partitioning set; applying the extended M-ary modulation technique during the use of QOS for coding in order to embed the message in the 2-D partitioning set; coding the copyrighter key in order to embed a synchronization recovery sequence; and allocating randomly the watermark in the 2-D partitioning set by using the coded copyrighter key.
  • 2-D two-dimensional
  • a method for detecting a watermark in the image is characterized by comprising: separating Y component from the image; estimating a watermark signal from the Y component; estimating an affine transform parameter from the watermark signal by using an autocorrelation function; recovering the Y component by using the estimated affine transform parameter; checking a watermark in the Y component by using the autocorrelation function; and decoding a message from the watermark signal by using QOS.
  • the method further comprises correcting errors when the decoded message has errors.
  • the autocorrelation function comprises: applying a hard-decision of the estimated watermark signal; calculating the autocorrelation function after the hard-decision; finding periodic peaks in the autocorrelation function; and estimating the affine transform parameter by using the periodic peaks.
  • Fig. 1 is a block diagram of a device for self-reference watermarking by using the extended M-ary modulation method based on finite field sequences and QOS according to the preferred embodiment of the present invention.
  • Fig. 2 is a flowchart showing that a watermark embedding unit embeds a watermark during a method for self-reference watermarking using the extended M-ary modulation method based on finite field sequences and QOS according to the preferred embodiment of the present invention.
  • Fig. 3 is a flowchart showing a method for determining watermark strength according to the preferred embodiment of the present invention.
  • Fig.4 is a flowchart showing a process for coding a message to be embedded by a copyrighter as the copyrighter's secret key according to the preferred embodiment of the present invention.
  • Fig. 5 is a flowchart showing that the watermark-detecting unit detects the watermark during a self-reference watermarking method by using the extended M-ary modulation method based on QOS and finite field sequences according to the preferred embodiment of the present invention.
  • Fig. 1 is a block diagram of a device for self-reference watermarking using the extended M-ary modulation method based on QOS and finite field sequences according to the preferred embodiment of the present invention.
  • the device consists of the watermark embedding unit 1 and the watermark detecting unit 3.
  • the watermark embedding unit 1 functions by embedding a watermark in an image and the watermark detecting unit 3 functions by detecting a watermark from the image.
  • the watermark embedding unit 1 and the watermark detecting unit 3 can be included in one device, but they are constituted as individual devices.
  • Fig. 2 is a flowchart showing that the watermark embedding unit embeds a watermark during a method for self-reference watermarking using the extended M-ary modulation method based on QOS and finite field sequences according to the preferred embodiment of the present invention. As shown in Fig. 2, the watermark embedding unit transforms RGB components of image to YUN components at step 10.
  • RGB is a way of representing color to be defined by red, green, and blue.
  • YUV is a way of representing color to be defined that the luminance is expressed as Y component and the chrominance is expressed as U and V components, considering the fact that a person's eye is sensitive to luminosity.
  • Use of YUV color image has a possible advantage upon considering the property of compression when embedding a watermark. The sense of sight in a human is more sensitive to luminance Y than chrominance UV when seeing an image.
  • Equation 1 describes that the watermark embedding unit transforms RGB components to YUV components as follows: Equation 1
  • a watermark embedding unit extracts only Y component at step 20.
  • a watermark can be embedded without image format, and the image need not depend on whether it is gray-level picture or a color picture.
  • the watermark embedding unit determines the intensity of embedding a watermark using the separated Y component, considering the entire properties of image and regional properties of image at step 30. In particular, this will be described as shown in Fig. 3.
  • Fig. 3 is a flow chart showing a method for determining the intensity for embedding a watermark according to the preferred embodiment of the present invention. As shown in Fig 3, the watermark embedding unit is divided into two steps and determines the intensity for embedding a watermark (watermark strength).
  • the watermark embedding unit determines a global watermark strength based on the overall complexity of image at step 310.
  • the watermark embedding unit partitions the image to a texture region, a flat region, and an edge region at step 320. Also, the watermark embedding unit partitions the edge region to the width edge, the length edge, 45' diagonal edge, and 135' diagonal edge.
  • the watermark embedding unit determines watermark strength at each region at step 330.
  • the watermark embedding unit cannot embed a watermark in a simple region but rather enhances watermark strength in a complex region.
  • the watermark embedding unit encodes the message to be embedded by the copyrighter as the copyrighter's secret key if watermark strength is determined at step 60. In particular, it will be described as shown in Fig.4.
  • Fig. 4 is a flowchart showing a process for encoding a message to be embedded by the copyrighter as the copyrighter's secret key according to the preferred embodiment of the present invention.
  • the watermark embedding unit establishes a 2-D set partition of the message to be coded and the copyrighter key by using finite field sequences. For robust resistance to cropping attack, the watermark is embedded as a unit block which is smaller than the image.
  • the watermark embedding unit establishes a 64x64 block as unit block, and the unit blocks can be partitioned into 16 sets of cardinality 256.
  • the watermark embedding unit partitions the unit block as a set by applying a finite field sequence.
  • a finite field sequence is best described in terms of trace function of the finite field.
  • a finite field sequence from GF(p n ) to GF(p) partitions a set of cardinality p a into p sets of cardinality p n .
  • a method that the watermark embedding unit partitions the unit block using a finite field sequence into a set is applied as follows:
  • the trace function from GF(2 12 ) to GF(2 4 ) partitions a block of the image into 16 cells of size 256 as follows:
  • Tr( ⁇ ct+d ) is allocated to each slot, where 0 ⁇ t ⁇ 64x64 and d is an arbitrary integer which can be determined by the watermark embedding unit.
  • Slots of the same allocated value are grouped as a cell.
  • the parameter in the process can be used as the copyrighter's secret key, having space of (2 12 -l)x ⁇ (2 12 -1), where ⁇ (.) is the Euler phi function.
  • a finite field sequence from GF(q n )/0 to GF(q) as described in the above definition is called the m-sequence, where q is a prime.
  • the watermark embedding unit encodes the message to properly embed the copyrighter's message in a block by 2-D set partition at step 410.
  • the procedure that the watermark embedding unit encodes the message is described as follows.
  • the watermark embedding unit uses the extended M-ary modulation, which is enhanced by using QOS, in order to embed L bits of message.
  • M-ary modulation uses a family of sequences that are mutually orthogonal to each other.
  • An extended m-sequence and a GMW (Gordon, Mills and
  • the maximum Iog 2 T+l bit can be embedded in biorthogonal modulation.
  • QOS can be made by well-known Gold sequences, Kasami sequences, or binary
  • the QOS set is llx 32, 9x 64, 23x 128, 21x 256 respectively.
  • an exponent of 2 was used among this set.
  • 16x 256 set is used.
  • unit can embed information of 12 bit per one period in orthogonal modulation and 13 bit
  • the watermark embedding unit can embed — bits into each of given H cells
  • a certain sequence is allocated as message.
  • the remaining cells are applied by the same method as the above method.
  • the watermark embedding unit encodes as the copyrighter's key for
  • M-H cells are constituted with synchronization recovery sequence, where H
  • ⁇ (t) is a sequence set that has (M-H)xR period, is constituted with
  • Equation 5 Equation 5
  • the watermark embedding unit performs a randomization by using a secret key when embedding a watermark into the unit block at step 430 to ensure that only a copyrighter can recognize watermark for absolute confidentiality.
  • the watermark embedding unit may embed the watermark in Y component after generating the watermark sequence and determining the watermark strength through procedures as shown in Figs. 3 and 4 at step 110.
  • Equation 6 Assuming that the value of the luminance component of image in a unit block of each NxN refers to p(x,y) 7 this can be represented as Equation 6.
  • p ⁇ ,y) p( ⁇ ,y) +a( ⁇ ,y) ⁇ w( ⁇ ,y) where, 0 ⁇ x,y ⁇ N, ⁇ (x,y) is a perceptual weighting factor, where HVS (Human
  • w(x,y) is an encoded watermark value.
  • the watermark embedding unit transforms the watermark-embedded Y w component and the UV components of original image into RGB components at step 130. This step can be represented as Equation 7. Equation 7
  • the method for detecting a watermark in the watermark-embedded image by the watermark embedding unit comprises three steps for estimating the watermark, synchronization recovery, and watermark decoding. These points will be described in further detail by referring to Fig.5.
  • Fig. 5 is a flowchart showing that the watermark detecting unit detects the watermark during a self-reference watermarking method by using the extended M-ary modulation method based on QOS and finite field sequences according to the preferred embodiment of the present invention.
  • the watermark detecting unit transforms RGB color space into YUV color space during a decision making step at step 500, and extracts Y component at step 510. Since steps 500 and 510 are the same as the steps when the watermark embedding unit embeds the watermark, that description can be omitted.
  • the watermark detecting unit estimates the watermark signal (step 520). Specifically, the watermark detecting unit referring to a blind detector can detect the watermark without using an original image. Accordingly, the watermark detecting unit recognizes power of image as the main noise source. Upon rating this noise compared to power of watermark, the main noise source may be hundreds of times as high as the power of watermark at maximum. In order to reduce the power of image, the watermark detecting unit performs a preprocessing called the whitening process. The preprocessing can improve performance of a self-reference watermarking method against desynchronization attacks.
  • the watermark detecting unit can estimate affine parameter by applying the autocorrelation method in order to recover a possible geometrical transformation (affine transform attack) using the estimated watermark signal (step 540). Given the estimated watermark sequence q(x,y the watermark detecting unit can calculate the autocorrelation function. However, since the estimated watermark signal uses real numbers and the calculation of the autocorrelation function requires a multiplication operation, its complexity is quite high. For example, it takes about 2 minutes to calculate the autocorrelation function of a 256x256. image on an 800MHz Pentium-Ill PC with 128MB main memory.
  • the present invention since the original watermark signal is a sequence of ⁇ 1 when the watermark embedding unit embeds the watermark, it is necessary to calculate the autocorrelation function of 2D sequence of ⁇ 1 when the watermark detecting unit detects the watermark.
  • the present invention reduces the complexity of integer multiplication operation to bit-wise operation when the watermark detecting unit detects the watermark.
  • Equation 8 r : ⁇ -tl ⁇ ⁇ 0,l ⁇
  • Equation 9 correlation N-2xd H (dJX) where d H ( ⁇ _',b denotes the Hamming distance between the two vectors X and
  • the watermark embedding unit partitions an image and embeds a
  • the watermark detecting unit can estimate
  • watermarking method additionally by using template signal.
  • Equation 11 in a matrix form.
  • the watermark detecting unit estimates the affine parameter by applying the autocorrelation function method at step 530.
  • the watermark detecting unit performs the following four steps by using the watermark signal estimated at step 530.
  • the hard-decision threshold value is 0.
  • the watermark detecting unit performs the process for finding the periodic peaks and the process for estimating the affine parameter separately.
  • the watermark detecting unit uses various schemes in order to enhance the accuracy of estimating the affine parameter.
  • the watermark detecting unit can use the properties of affine parameter itself. Namely, since peaks always exist on a line, the watermark detecting unit can exclude incorrect peaks. Furthermore, when the watermarked image is large enough, the watermark detecting unit can improve the performance by averaging the parameters.
  • the watermark detecting unit can obtain peaks by calculating the autocorrelation function.
  • the watermark detecting unit inverts the Y component by use of the affine parameter at step 540. Also, the watermark detecting unit can estimate flipping, mirroring or rotation of 90xn after the procedure of recovering the Y component.
  • the watermark detecting unit performs synchronization recovery against the cropping attack at step 550. Assuming that the watermarked image is cropped and not transformed geometrically, the watermark detecting unit can detect the watermark signal theoretically. However, if the image is cropped by N'. D N', which size is available to recover, the watermark detecting unit can detect the watermark signal not only when a cropping attack occurs but also when geometric attacks occur. In order to detect the watermark signal from the cropped image, there must be an image whose size is at least larger than NxN.
  • the image recovery of the watermark detecting unit for the image translation using a synchronization signal is as follows. It can be assumed that there is no geometric attack in the image when the watermark detecting unit recovers the image by using affine parameter. As the synchronization recovery sequence is embedded together with the watermark signal into each block, the watermark detecting unit can estimate the
  • the synchronization recovery sequence may be used as a threshold of the function for
  • the false alarm rate can be calculated as follows assuming that the
  • threshold is set to 256 out of 1024 when the correlation is calculated using the
  • the watermark detecting unit detects the watermark from the image recovered
  • the watermark detecting unit determines that a
  • the watermark detecting unit terminates the procedure for detecting watermark at step 580.
  • the watermark detecting unit decodes the message at step 590.
  • the block-wise watermark folding scheme may be used in order to improve the performance of watermark detecting unit.
  • the watermark detecting unit uses the extended M-ary modulation method based on QOS to decode the message.
  • the calculation of the correlation by applying the extended M-ary modulation method based on QOS to the watermarked image is as follows:
  • Equation 13 where w t (i) is the estimated watermark sequence in the cell / and m,(i) is the sequence having index ; " . Both sequences are of length R.
  • the watermark detecting unit chooses the maximum correlated sequence as the embedded sequence and reads the information according to the embedded sequence. Then, the watermark detecting unit determines whether or not error occur in the watermark at step 600. If some error occur, the watermark detecting unit corrects the error of decoded watermark by using ECC (Error Correcting Codes) at step 610. In this correction, the present invention uses FEC (Forward Error Correction) to improve the performance of the watermark detecting unit.
  • ECC Error Correcting Codes
  • the watermark detecting unit chooses another sequence different from the embedded sequence.
  • the correlation of embedded sequence does not become the maximum value.
  • the sequence chosen by the watermark detecting unit still has a relatively high correlation.
  • the watermark detecting unit can improve its performance by exploiting this property.
  • the watermark sequence to be embedded into the image must be encoded in association with ECC.
  • CRC cyclic redundancy check
  • MDS maximum distance separable codes have high error correction capability.
  • the watermark detecting unit determines again whether or not any error remains at step 620. If an error still exists, the watermark detecting unit terminates the procedure for detecting the watermark without finishing the watermark detection at step 630.
  • the watermark detecting unit terminates the procedure for detecting the watermark by finishing the watermark detection at step 640.
  • the present invention can provide for enhanced copyright protection. Also, the present invention solves the problem of conventional watermark algorithms that require the original image to detect the embedded watermark.
  • the present invention since the present invention has the same resilience as the method that does not use the copyrighter's key, it can be applied to a public watermark method.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Editing Of Facsimile Originals (AREA)
  • Image Processing (AREA)

Abstract

La présente invention concerne un procédé d'inclusion et de détection d'un filigrane. Le procédé de détection d'un filigrane évalue le paramètre de transformation affine grâce à un motif périodique du filigrane inséré, et décode le filigrane en appliquant le paramètre de transformation affine à une image. En outre, pour améliorer la capacité du canal du filigrane, le procédé de l'invention exploite la modulation à base m étendue fondée sur des séquences de corps fini et de qualité de service. En outre, pour réduire la complexité, le procédé de l'invention applique un calcul au niveau du bit à la fonction d'autocorrélation.
PCT/KR2002/001205 2002-06-25 2002-06-25 Procede et appareil d'insertion et d'extraction de filigrane WO2004014079A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/KR2002/001205 WO2004014079A1 (fr) 2002-06-25 2002-06-25 Procede et appareil d'insertion et d'extraction de filigrane
AU2002346328A AU2002346328A1 (en) 2002-06-25 2002-06-25 Method and apparatus for inserting and extracting watermark

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/KR2002/001205 WO2004014079A1 (fr) 2002-06-25 2002-06-25 Procede et appareil d'insertion et d'extraction de filigrane

Publications (1)

Publication Number Publication Date
WO2004014079A1 true WO2004014079A1 (fr) 2004-02-12

Family

ID=31492719

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2002/001205 WO2004014079A1 (fr) 2002-06-25 2002-06-25 Procede et appareil d'insertion et d'extraction de filigrane

Country Status (2)

Country Link
AU (1) AU2002346328A1 (fr)
WO (1) WO2004014079A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005045763A1 (fr) * 2003-11-04 2005-05-19 Canon Kabushiki Kaisha Methode d'estimation d'une relation affine entre des images

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5875249A (en) * 1997-01-08 1999-02-23 International Business Machines Corporation Invisible image watermark for image verification
JPH1155639A (ja) * 1997-02-24 1999-02-26 Nec Corp デジタルデータのエンコードシステム及び電子透かしデータ挿入方法並びに制御プログラムを格納した記憶媒体
JPH11331548A (ja) * 1998-05-15 1999-11-30 Nec Corp 画像属性変更装置と電子透かし装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5875249A (en) * 1997-01-08 1999-02-23 International Business Machines Corporation Invisible image watermark for image verification
JPH1155639A (ja) * 1997-02-24 1999-02-26 Nec Corp デジタルデータのエンコードシステム及び電子透かしデータ挿入方法並びに制御プログラムを格納した記憶媒体
JPH11331548A (ja) * 1998-05-15 1999-11-30 Nec Corp 画像属性変更装置と電子透かし装置

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005045763A1 (fr) * 2003-11-04 2005-05-19 Canon Kabushiki Kaisha Methode d'estimation d'une relation affine entre des images
US7532768B2 (en) 2003-11-04 2009-05-12 Canon Kabushiki Kaisha Method of estimating an affine relation between images

Also Published As

Publication number Publication date
AU2002346328A1 (en) 2004-02-23

Similar Documents

Publication Publication Date Title
JP4250187B2 (ja) 空間領域における頑強で可逆なデータ隠蔽およびデータ復元のためのシステムおよび方法
Yang et al. A contrast-sensitive reversible visible image watermarking technique
US20090220070A1 (en) Video Watermarking
Lancini et al. A robust video watermarking technique in the spatial domain
US20090252370A1 (en) Video watermark detection
EP0984616A2 (fr) Méthode et appareil pour filigrane digital
US20090136083A1 (en) Coefficient Selection for Video Watermarking
KR100977712B1 (ko) 구조적 멀티패턴 워터마크 생성 장치 및 방법과 이를이용한 워터마크 삽입 장치 및 방법과 워터마크 검출 장치및 방법
US20040017926A1 (en) Steganographic image encoding
CN110599388B (zh) 一种基于定位点辅助的盲鲁棒数字水印嵌入和检测方法
US20090226030A1 (en) Coefficient modification for video watermarking
Csurka et al. A Bayesian approach to affine transformation resistant image and video watermarking
Rakhmawati Image fragile watermarking with two authentication components for tamper detection and recovery
Padmaa et al. Zig-zag pvd–a nontraditional approach
Liu et al. A robust DWT-based blind data hiding algorithm
CN113592698B (zh) 基于十六元数矩的多视角彩色图像零水印处理方法及系统
Ernawan et al. Self-recovery in fragile image watermarking using integer wavelet transform
WO2004014079A1 (fr) Procede et appareil d'insertion et d'extraction de filigrane
Lancini et al. A robust video watermarking technique for compression and transcoding processing
Ho et al. Character-embedded watermarking algorithm using the fast Hadamard transform for satellite images
WO1998041017A1 (fr) Procede et systeme de codage d'informations
Chen et al. Image watermarking robust to print and generation copy
Wah Image Watermarking and Data Hiding Techniques
Lee et al. Multi-bit video watermarking based on 3D DFT using perceptual models
David et al. Image Authentication Techniques and Advances Survey

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ OM PH PL PT RO RU SD SE SG SI SK SL TJ TM TN TR TT TZ UA UG US UZ VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

WWW Wipo information: withdrawn in national office

Country of ref document: JP