1 multimedia security part ii mesh watermarking overview 2008/07/17 presenter : ming-zhou liao...
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Multimedia Security Part IIMultimedia Security Part IIMesh Watermarking Overview Mesh Watermarking Overview
2008/07/17Presenter : Ming-Zhou Liao
Intelligent System/Media Processing Laboratory, Department of Computer Science and Information
Engineering, National Cheng Kung University
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OutlineOutline
------------------------------Part I-------------------------------IntroductionBasic Concepts of 3D WatermarkingTwo Classical Scheme of Robust and Fragile Watermarking------------------------------Part II------------------------------Hierarchical Blind Watermarking of 3D Triangular Meshes
Wang, Kai; Lavoue, Guillaume; Denis, Florence; Baskurt, Atilla; Multimedia and Expo, 2007 IEEE International Conference
------------------------------Part III------------------------------ConclusionRelative Reference ResourcesHomework!?
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OutlineOutline
------------------------------Part I-------------------------------IntroductionBasic Concepts of 3D WatermarkingTwo Classical Scheme of Robust and Fragile Watermarking------------------------------Part II------------------------------Hierarchical Blind Watermarking of 3D Triangular Meshes
Wang, Kai; Lavoue, Guillaume; Denis, Florence; Baskurt, Atilla; Multimedia and Expo, 2007 IEEE International Conference
------------------------------Part III------------------------------ConclusionRelative Reference ResourcesHomework!?
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MotivationMotivation
“Everything” is digital these daysA copy of a digital media element is identical to the originalHow can an owner protect their content?What does all of this mean in terms of law?
What does it mean to own “bits”?
The digital rights management problem (DRM) has been addressed for many information types
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What Is Multimedia Security?What Is Multimedia Security?
What do we want from a security system?Access and copy control
Playback controlRecord controlGeneration control...
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What Is Multimedia Security? (Cont.)What Is Multimedia Security? (Cont.)
Goals of cryptography for classical data streams:ConfidentialitySignature & watermarkAuthentication Identifications and access control Non-repudiations
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What Is Multimedia Security? (Cont.)What Is Multimedia Security? (Cont.)
Goals of cryptography for multimedia streams:Multimedia confidentiality (Encryption)Multimedia signature & watermarkMultimedia authentication Multimedia identifications and access control Multimedia non-repudiations
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What Is Multimedia Security? (Cont.)What Is Multimedia Security? (Cont.)
UnfortunatelyProblems of multimedia security are the same problem of cryptography…Will it be illegal to remove security features from a data element?
In other words, security of multimedia systems depends on security of cryptographic systems
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Typical Cryptography SystemTypical Cryptography SystemTrusted UsersTrusted Users
Figure 1. Typical cryptography system – trusted users
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Typical Cryptography SystemTypical Cryptography System Distrusted Users Distrusted Users
Figure 2. Typical cryptography system – distrusted users
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Media Elements Media Elements
Covered from many different fields:AudioVideoDocuments (including HTML documents)ImagesPrograms (executable code)Graphics
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Multimedia Security - Tools Set Multimedia Security - Tools Set
There are some ways which can achieve the multimedia security:
EncryptionAuthenticationHashingTime-stampingWatermarking
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Multimedia Security - Applications Multimedia Security - Applications
Some associated applications are addressed as follow:
PrivacyForgery detection (watermarking)Copyright protection (watermarking)Proof of purchaseProof of deliveryIntruder detection
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What Is Watermarking? What Is Watermarking?
The use of perceptually invisible authentication techniques
“Controlled” distortion is introduced in a multimedia elementVisible watermarks also exists
GoalsVerify the owner of a digital dataDetect forgeries of an original dataIdentify illegal copies of the dataPrevent unauthorized distribution
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What Is Watermarking? (Cont.)What Is Watermarking? (Cont.)
Main principlesTransparency
The watermark is not visible in the image under typical viewing conditions
Robustness to attackThe watermark can still be detected after the image has undergone linear and/or nonlinear operationsRobustness is crucial to the success of data embedding
CapacityThe technique is capable of allowing multiple watermarks to be inserted into the image with each watermark being independently verifiableShould be embed a nontrivial amount of information into models
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Two Type of WatermarkingTwo Type of Watermarking
Robust watermarkingDesigned for the sender to check the copyright ownership
Fragile watermarkingDesigned for the receiver to verify the authentication of the received data Major functions
Integrity checkingChanged region locating
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Two Type of Watermarking (Cont.)Two Type of Watermarking (Cont.)
Table 1 A comparison of fragile watermarking and digital signature applied in 3D model.
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Extraction StrategiesExtraction Strategies
Private watermarkingNeeds original model and watermarks
Public (blind) watermarkingCan extract watermarks in the absence of the original model and the watermarksAll fragile watermarking are public watermarking scheme
Semi-public watermarkingDoes not need original model but the original watermarks are necessary for comparing stage
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OutlineOutline
------------------------------Part I-------------------------------IntroductionBasic Concepts of 3D WatermarkingTwo Classical Scheme of Robust and Fragile Watermarking------------------------------Part II------------------------------Hierarchical Blind Watermarking of 3D Triangular Meshes
Wang, Kai; Lavoue, Guillaume; Denis, Florence; Baskurt, Atilla; Multimedia and Expo, 2007 IEEE International Conference
------------------------------Part III------------------------------ConclusionRelative Reference ResourcesHomework!?
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Embedding TargetEmbedding Target
Representation of 3D modelsPolygonal meshesCurved surfacesSolid boundVoxel enumeration
Embedding candidateGeometry is the best candidate for data embeddingNongeometrical components have higher chances of alteration or removal than geometry
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Embedding Primitives of Polygonal ModelEmbedding Primitives of Polygonal Model
Geometrical embedding primitivesThe coordinates of points and vertices can be modified to embed dataAdvantageous to employ primitives that are Invariant to certain class of geometrical transformations
Invariant to translation and rotationLength of lineArea of a polygonVolume of a polyhedron
Invariant to rotation, uniform-scaling, and translationRatio of the areas of two polygonal
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Embedding Primitives of Polygonal Model Embedding Primitives of Polygonal Model (cont.)(cont.)
Topological embedding primitivesWatermark can be embedded by changing the topology of a modelThe changes may also involve change in geometry as a side effect
E.g. inserting or displacing vertices
Figure 3. Simple examples of topological embedding primitives.
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Embedding Primitive ArrangementEmbedding Primitive Arrangement
Image or audio data already have regular implicit ordering of embedding primitives
Topological arrangementEmploys topological adjacency to arrange embedding primitivesNot resistant to topological modification
Quantitative arrangementEmploys inequality relations among the quantities
E.g. Area of triangles, volumes of polyhedrons
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Common Attack Strategies Common Attack Strategies
The watermarking approach should withstand all of possible alterations ideally
Similarity transformsRotationUniform scaling Translation
Affine transforms Non-uniform scalingProjective distortions
Noising and de-noisingWhite Gaussian noise additionLaplacian smoothing
Figure 4. Adding random noise.
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Common Attack Strategies (Cont.)Common Attack Strategies (Cont.)
Connectivity attacksVertex reorderingRe-triangulation
Re-samplingSimplificationMesh refinementRemeshing (introduced later)
Topological attacksCropping
Compression attacksPoint coordinates quantizationFormat conversion attacks
Figure 5. Simplification of triangular meshes.
Figure 6. Enhancement of the bunny.
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Common Attack Strategies (Cont.)Common Attack Strategies (Cont.)
Geometrical deformationsBendingMesh editingMesh morphingLocal deformations
Figure 7. Watermarked
models and various attacks.
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RemeshingRemeshing
The process refers to approximation such geometry using a mesh with (semi)-regular connectivity
Figure 8. A series of surface covered with regular or semi-regular regions.
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Regularity of MeshesRegularity of Meshes
In topological mesh modeling our only concern is mesh structure
How faces, edges and vertices are related with each other
Topological regularity as all faces and vertices have the same combinatorial property
i.e. having the same size and same valence, respectivelyThe valence of a vertex is defined as the number of edge-ends that emanates from that vertexThe face size is counted as the number of edge sides (also called half-edges) belonging to a face
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Regularity of Meshes (Cont.)Regularity of Meshes (Cont.)
Figure 9. A series of examples of regular mesh object.
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OutlineOutline
------------------------------Part I-------------------------------IntroductionBasic Concepts of 3D WatermarkingTwo Classical Scheme of Robust and Fragile Watermarking------------------------------Part II------------------------------Hierarchical Blind Watermarking of 3D Triangular Meshes
Wang, Kai; Lavoue, Guillaume; Denis, Florence; Baskurt, Atilla; Multimedia and Expo, 2007 IEEE International Conference
------------------------------Part III------------------------------ConclusionRelative Reference ResourcesHomework!?
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Triangle Similarity Quadruple AlgorithmTriangle Similarity Quadruple Algorithm
Pair of dimensionless quantities{ b/a, h/c } or { θ1, θ2 }
Micro-Embedding Primitive (MEP)Each MEP stores a quadruple of values {Maker, Subscript, Data1, Data2}
Figure 11. A macro-embedding-primitive.
Figure 10. Examples of dimensionless quantities that define a set of similar triangles.
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Classical Strategy of Fragile Watermarking Classical Strategy of Fragile Watermarking
Computes two indices for every vertexLocation indexValue indexHash function
Perturbed every vertex to make two indices equalFigure 12. An example of triangular mesh topology.
Figure 13. Modify the coordinate of vertex to match the value of hash function.
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Problems of These ApproachProblems of These Approach
TSQ Algorithm Resistant
RotationTranslationUniform scaling
Classical fragile watermarking Causality problem
Former processed vertex will be changed by later processed neighboring vertex
Convergence problemUser can not control the distortion induced by perturbing process
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OutlineOutline
------------------------------Part I-------------------------------IntroductionBasic Concepts of 3D WatermarkingTwo Classical Scheme of Robust and Fragile Watermarking------------------------------Part II------------------------------Hierarchical Blind Watermarking of 3D Triangular Meshes
Wang, Kai; Lavoue, Guillaume; Denis, Florence; Baskurt, Atilla; Multimedia and Expo, 2007 IEEE International Conference
------------------------------Part III------------------------------ConclusionRelative Reference ResourcesHomework!?
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Introduction of The PaperIntroduction of The Paper
Embed two watermark into different resolution levelsGeometrically robust watermark
Synchronizing and quantizing watermark primitives according to the edge length of the coarsest level
High-capacity watermarkPermutation of the norms of a group of wavelet coefficients
Both watermark are blind and invariant to similarity transformations
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Proposed FrameworkProposed Framework
Pre-procedureThe irregular mesh is remeshed to generate a corresponding semi-regular mesh
Normally has a negligible geometrical distortion More favorable for compression thanks to its simple connectivity
Extraction Suppose that a mesh with the same semi-regular connectivity can be reconstructed
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Proposed Framework (Cont.)Proposed Framework (Cont.)
Lazy wavelet decomposition mechanismA group of four triangles is merged in oneThree of the six initial vertices are conserved
in the lower resolution
This kind of wavelet analysis is applicable only on semi-regular triangular meshes
Figure 14. Illustration of 3D triangular mesh wavelet analysis.
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Proposed Framework (Cont.)Proposed Framework (Cont.)
Multiresolution analysis is a very suitable tool for hierarchical watermarking
No inter-infection between different watermarks if they are inserted in different levels
Figure 15. Hierarchical watermarking of a semi-regular mesh.
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Robust and Blind WatermarkingRobust and Blind Watermarking
All the norms are altered to locate in the middle of the nearest correct subinterval
The synchronizing mechanism and the watermarking primitives are separated
The causality problem is avoided
Figure 16. Three quantization examples of coefficient norms.
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High-Capacity Blind WatermarkingHigh-Capacity Blind Watermarking
High-capacity watermark embedding mechanismThe wavelet coefficients are indexed according to the lengths of their associated edgesThe order sequence of coefficients is a permutation of the n numbers thus has n! possibilitiesSort and modify the residues of the norms to achieve a better imperceptibility
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High-Capacity Blind Watermarking (Cont.)High-Capacity Blind Watermarking (Cont.)
The modified norm is determined by
Table 2. Example of high-capacity watermark embedding steps.
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High-Capacity Blind Watermarking (Cont.)High-Capacity Blind Watermarking (Cont.)
The edges can be divided into several groupsMake the watermark less fragileAvoid the possible floating number calculation errors
Correspondence between bit strings and possible permutation has to be established
For two permutationsThe one with a bigger first number represents a bigger bit stringIf the first number is the same then compare the second number, and so on
1, 2, 3, …, n-1, n 0, 0, …, 0, 01, 2, 3, …, n, n-1 0, 0, …, 0, 1
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Experimental ResultsExperimental Results
Figure 17. Capacity comparison of different methods.
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Experimental Results (Cont.)Experimental Results (Cont.)
Figure 18. Hierarchical watermarking example: (a) original semi-regular mesh (b) watermarked mesh
Figure 19. Four attacked watermarked meshes: (a) 0.4% additive noise (b) 6 average smoothing (c) enhancement (d) 7-bit quantization
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Experimental Results (Cont.)Experimental Results (Cont.)
Table 3. Results of robustness experiments
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Comments Comments
Need to prepare the remeshing techniques that are insensitive to connectivity changes
The high-capacity watermark is somewhat fragile
The “robust” watermark can’t withstand the local deformation and cropping
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OutlineOutline
------------------------------Part I-------------------------------IntroductionBasic Concepts of 3D WatermarkingTwo Classical Scheme of Robust and Fragile Watermarking------------------------------Part II------------------------------Hierarchical Blind Watermarking of 3D Triangular Meshes
Wang, Kai; Lavoue, Guillaume; Denis, Florence; Baskurt, Atilla; Multimedia and Expo, 2007 IEEE International Conference
------------------------------Part III------------------------------ConclusionRelative Reference ResourcesHomework!?
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Conclusion Conclusion
Watermarking techniques for 3D model face many challenges for the follow reasons
Compared with images, only a small amount of data is available for watermark embeddingNo unique representation nor implicit ordering of model data existsNo robust transformation field could be used to embed watermark
Multiresolution representation may overcome this issue
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Conclusion (Cont.) Conclusion (Cont.)
Watermarking is still an interesting research area with many interesting problems:
Where will it be useful?Will watermarking only be used a second-tier security systemWill there be significant theoretical developments?
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OutlineOutline
------------------------------Part I-------------------------------IntroductionBasic Concepts of 3D WatermarkingTwo Classical Scheme of Robust and Fragile Watermarking------------------------------Part II------------------------------Hierarchical Blind Watermarking of 3D Triangular Meshes
Wang, Kai; Lavoue, Guillaume; Denis, Florence; Baskurt, Atilla; Multimedia and Expo, 2007 IEEE International Conference
------------------------------Part III------------------------------ConclusionRelative Reference ResourcesHomework!?
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Relative Reference ResourcesRelative Reference Resources
JournalComputerized Medical imaging and GraphicsCVGIP: Computer Vision and Image UnderstandingCVGIP: Graphical Models and Image ProcessingDigital Signal Processing: A Review JournalIEE Proceedings Part I: Communications Speech and VisionIEEE Trans. Image ProcessingIEEE Trans. Pattern Analysis and Machine IntelligenceIEEE Trans. Systems, Man, and CyberneticsImage and Vision ComputingInt’I Journal of Computer Vision
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Relative Reference Resources (Cont.)Relative Reference Resources (Cont.)
Int’I Journal on Document Analysis and RecognitionInt’I Journal of Pattern Recognition and Artificial IntelligenceJournal of Electronic ImagingJournal of Imaging Science and TechnologyJournal of Imaging TechnologyJournal of Mathematical Imaging and VisionJournal of the Optical Society of America A: Optics Image ScienceJournal of Vision and ApplicationsMultidimensional Systems and Signal Processing
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Relative Reference Resources (Cont.)Relative Reference Resources (Cont.)
Optical EngineeringPattern Analysis and ApplicationsPattern RecognitionPattern Recognition LettersPattern Recognition and Image Analysis (Moscow)Signal Processing (EURASIP)Signal Processing: Image Communication (EURASIP)The Transactions of The IEICE Series (Japan)
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Relative Reference Resources (Cont.)Relative Reference Resources (Cont.)
Proc. of conferences(3DIM) 2th Int’I Conf. on 3D Digital Imaging and Modeling(ACCV) Asian conf. Computer Vision(ASSP) IEEE Conf. Acoustics, Speech and Signal Processing(CVPR) IEEE Conf. Computer Vision and Pattern Recognition(EMM) 2th Int’I WK. on Energy Minimization Methods in CVPR(ICAIP) 8th Int’I Conf. Computer Analysis of Images and Patterns(ICCV) International Conf. Computer Vision(ICDAR) IAPR Conf. Document Analysis and Recognition
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Relative Reference Resources (Cont.)Relative Reference Resources (Cont.)
(ICSPAT) Int’I Conf. Signal Processing Applications & Technology(IGARSS) IEEE conf. Geographic and Remote-sensing Sciences(IPA) Int’I Conf. Image Processing and its Applications(IPTA) Int’I Conf. Image Processing: Theory and Applications(VCIP) SPIE’s Symp. Visual commun. And Image Processing
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Relative Reference Resources (Cont.)Relative Reference Resources (Cont.)
AssociationIEEE (the Institute of Electrical and Electronics Engineers)ACM (Association for Computing Machinery)IAPR (The International Association for Pattern RecognitionIS&T (The Society for Imaging Science and Technology)SPIE (The International Society for Optical Engineering)IASTED (The International Association of Science and Technology for Development)
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OutlineOutline
------------------------------Part I-------------------------------IntroductionBasic Concepts of 3D WatermarkingTwo Classical Scheme of Robust and Fragile Watermarking------------------------------Part II------------------------------Hierarchical Blind Watermarking of 3D Triangular Meshes
Wang, Kai; Lavoue, Guillaume; Denis, Florence; Baskurt, Atilla; Multimedia and Expo, 2007 IEEE International Conference
------------------------------Part III------------------------------ConclusionRelative Reference ResourcesHomework!?
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Homework!?Homework!?
Defense groupTo do
Design a suitable image watermarking algorithm to resist other malicious manipulation
Must satisfy the follow constrains
ConstrainsPeak Signal to Noise Ratio (PSNR): 38 ↑Watermark correlation: 0.7 ↑
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Homework!? (Cont.)Homework!? (Cont.)
Attack groupTo do
Attack the target watermarked image for disturbing watermark extraction
Must satisfy the follow constrains
ConstrainsPeak Signal to Noise Ratio (PSNR ): 38 ↑Watermark correlation: 0.7 ↓
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Homework!? (Cont.)Homework!? (Cont.)
Recommend toolMATLAB
ISMP FTPAddress: 140.116.247.34Port: 400Account: ismpPassword: ismp 13
Target image & watermark informationDecided by defense team
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RecruitRecruit
Benefits about being activity managerNo need to sweep the floor on the ground every weekNo need to charge the function of fluorescent light in lab
No need to borrow the key for seminar every weekNo need to get up early for setting up the stuff for seminar every weekMay be pay raise someday!?You are the only one……It’s cool………
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Q&AQ&A
Thank you for your listening!