1、MATLAB实现

计算图像哈希值SHA-512，在文献[1]提到的算法如下：

% Example Code:    Create an MD5 crypto-hash of an arbitrary string, "str"
% Main class of interest:    System.Security.Cryptography.HashAlgorithm% Example String to hash with MD5
% str = 'hello there big world';
% str= ' i love china';
myx=imread('lena.jpg');% Image_As_A_vector = reshape(typecast(myx, 'uint8'), 1, []));
array_in=char(strjoin(string(reshape(myx,1,[]))));
str=array_in;
% Create any specified cryptographic hasher. 
% Supported string args include 'MD5', 'SHA1', 'SHA256', 'SHA384', 'SHA512'.
% That's what I could figure out by random guessing...  'SHA3' didn't work.
% hasher = System.Security.Cryptography.HashAlgorithm.Create('MD5');
hasher = System.Security.Cryptography.HashAlgorithm.Create('SHA512');
% Convert the char