To solve the problems of the seal images gesture adjusting and the seal images matching,Delaunay triangulation cutting al-gorithm in computational geometry is imported.

This paper proposes a fragile watermarking method for image authentication,in the method,the original image is firstly divided into 8×8 blocks,then choose the region to be protected.

Therefore content-based multimedia data authentication technique has become a research focus, within which image authentication is important and crucial.

A wavelet-based image watermarking algorithm for tamper-proofing;

Multiwavelet image watermarking algorithm based on genetic algorithms;

Improving on fractal image watermarking algorithm;

New algorithm for embedding and detection image watermark;

Adaptive image watermarking algorithm based on block DCT transform and Arnold shuffling;

A robust image watermarking scheme based on a trusted third party;

In order to embed watermark image, we process the watermark image by classification, one part embedded in space domain with blind w.

The algorithm splits the original image to some blocks,using correlation of neighboring pixels,a bit watermark is embedded into erery block,the watermark is a binary sequence based on significative watermark image,and using key and average of prediction swatch to determine the position of watermark in the image block,which can assure very good security for the watermark.

The process of embedding,withdrawing and checking watermark image is analyzed,the method of picture’s Arnold trans-formation and relativity examination is researched.