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Transcript of tgy
Mrunalini Reddy Do you know what watermarks are ? Did you know!?? The term Watermarks was given since the marks resemble the effects of water on paper History of Watermarking More than 700 years ago, watermarks were used in Italy to indicate the paper brand and the mill that produced it.
By the 18th century watermarks began to be used as Anticounterfeiting measures on money and other documents. WaterMarking
Digital watermarks are designed to be completely
invisible, or in the case of audio clips, inaudible
The bits representing the watermark must be
scattered throughout the file in such a way that they cannot be identified and manipulated Visible and Invisible Watermarks PURPOSE OF WATERMARKING C opyright protection
Data authentication Properties of Watermark >Invisibility
>Capacity (Number of bits can be hidden)
>Low error probability
>Image watermarking ( filtering, resizing, contrast enhancement, cropping, rotation... )
>Video watermarking ( frame averaging, frame dropping, frame swapping, statistical analysis, interpolation... ) >Video media is susceptible.
>Video content is sensitive .
>Video compression are computationally intensive.
>Video is BW hungry!
>For low bit-rate video ,watermarking poses additional challenges.
>Watermarking should be robust enough against frame drops!!! Challenges for Video Watermarking > Signal enhancement.
> Lossy compression
> Geometric transforms(translation,rotation, etc.)
> Data reduction (cropping, clipping, etc.)
> Multiple watermarking Watermarking Attacks original JPEG q=100
NC=0.999 JPEG q=80
NC=0.993 JPEG q=10
NC=0.557 >Pinnacle studio >Video Charge studio >Matlab >Windows XP movie maker WATERMARKING Thank you Softwares used visible both invisible