在未來，許多的商品以及影像，舉凡數位票卷、犯罪影像、醫學影像等等，都從傳統模式走向數位化，為了防止被惡意竄改，影像認證變得極為重要。
我們提出一個基於內容的半易碎浮水印方法，來驗證數位影像的合法性。模擬結果顯示，利用離散小波轉換低頻資訊的Zernike moments來取影像特徵值，增加了影像的堅韌性，會使得影像擁有半易碎的特質，換而言之，我們的方法不僅僅可以讓影像抗壓縮，也可以指出測試影像被修改的位置。
實驗結果顯示，我們可以指出影像被竄改的位置，更有高度的堅韌性，抵抗JPEG壓縮係數75以上的能力，實做上，這個方法兼具高強韌性及影像認證，非常適合用在路面影像監視系統上。

In the very near future, many products and transaction in our daily life will be done in the digital world. For example, tickets, crime images, and medical images are digital. In order to prevent the images from being tampered with, image authentication is extremely important.
A semi-fragile watermarking algorithm based on the image content is proposed to inspect and verify the legitimacy of an image. Simulation result shows that choosing the Zernike moments as features in the low pass wavelet band increases the robustness of image.
Experimental result shows that we can tell if an image is maliciously attacked or not and locate which block is tampered. Moreover, the image has high robustness against noise and JPEG compression with the quality factor Q 75. The technique can be used in an surveillance system for image authentication to prove the legality both the image and the surveillance system for digital forensic.

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