计算机仿真
計算機倣真
계산궤방진
COMPUTER SIMULATION
2014年
5期
293-296
,共4页
图像哈希%极谐变换%几何攻击%鲁棒
圖像哈希%極諧變換%幾何攻擊%魯棒
도상합희%겁해변환%궤하공격%로봉
Image hashing%Polar harmonic transform( PHT)%Geometric attack%Robust
针对现有图像哈希算法普遍存在抗几何攻击能力不强的缺点,提出了一种基于极谐变换( Polar Harmonic Transform, PHT)的鲁棒图像哈希算法。极谐变换是新近发展的一种正交矩变换方法,图像的变换幅值对旋转缩放具有不变性,利用这一特点用图像的极谐变换幅值生成图像。首先对图像进行极谐变换,然后将得到的幅值系数进行筛选量化得到二值序列,最后根据预先设计的密钥对二值序列进行置乱生成图像。仿真结果表明,上述算法对几何攻击和常规信号处理攻击均具有很强的鲁棒性,优于对比算法性能,能够用于图像识别、搜索、认证等方面的应用。
針對現有圖像哈希算法普遍存在抗幾何攻擊能力不彊的缺點,提齣瞭一種基于極諧變換( Polar Harmonic Transform, PHT)的魯棒圖像哈希算法。極諧變換是新近髮展的一種正交矩變換方法,圖像的變換幅值對鏇轉縮放具有不變性,利用這一特點用圖像的極諧變換幅值生成圖像。首先對圖像進行極諧變換,然後將得到的幅值繫數進行篩選量化得到二值序列,最後根據預先設計的密鑰對二值序列進行置亂生成圖像。倣真結果錶明,上述算法對幾何攻擊和常規信號處理攻擊均具有很彊的魯棒性,優于對比算法性能,能夠用于圖像識彆、搜索、認證等方麵的應用。
침대현유도상합희산법보편존재항궤하공격능력불강적결점,제출료일충기우겁해변환( Polar Harmonic Transform, PHT)적로봉도상합희산법。겁해변환시신근발전적일충정교구변환방법,도상적변환폭치대선전축방구유불변성,이용저일특점용도상적겁해변환폭치생성도상。수선대도상진행겁해변환,연후장득도적폭치계수진행사선양화득도이치서렬,최후근거예선설계적밀약대이치서렬진행치란생성도상。방진결과표명,상술산법대궤하공격화상규신호처리공격균구유흔강적로봉성,우우대비산법성능,능구용우도상식별、수색、인증등방면적응용。
Most existing image hashing algorithms are not robust enough to geometric attacks. To solve this prob-lem, a robust image hashing algorithm based on Polar Harmonic Transform( PHT) was proposed in this paper. The PHT is a recently developed orthogonal moment method, and the magnitudes of PHTs are invariant to image rotation and scaling. According to the feature. the magnitudes of PHTs were quantized into image digest. The images were transformed with Polar Harmonic firstly, then the derived magnitudes were selected and quantized into binary se-quence. At last, according to the previous key, the sequence was disturbed to receive the image digest. Simulation results show that the proposed hashing is robust to geometric attacks and conventional signal processing attacks, which outperforms the typical comparative algorithms and can be used in image identification, search and authentication, etc.