Watermarking

Modified on 2010/12/20 13:31 by Administrator — Categorized as: Digital Image Processing

protect the rights of their owners


조건


visible watermark

Image

Image

Invisible Watermark

깨지기 쉬운 워터마크

Image

강력한 워터 마크


Image

DCT-based watermarking

Mark insertion

Setp1 : 2-D DCT of the image

Setp2 : Locate its K largest coefficients,Image, by magnitude

Setp3 : Create a watermark by generating a K-element pseudo-random sequence of numbers,Image, taken from a Gaussian distribution.

Setp4

: Image

Setp5 : Inverse DCT of the result from step 4

Mark extraction

Setp1 : 2-D DCT of the image

Setp2 : Extract the K DCT coefficients Image

Image

otherwise : unmarked or different watermark

Setp3 : Image

Setp4

: Measure the similarity

Image

Setp5

Image