Image Hash algorithm based on quaternion matrix singular value decomposition and application thereof

The invention provides an image Hash algorithm based on quaternion matrix singular value decomposition, which comprises the following steps: S1, reading a color image, and zooming the size of the color image; s2, representing the scaled color image by using a quaternion matrix to obtain a complex matrix; s3, equally dividing the complex matrix into (shown in the description) sub-blocks with the same size; s4, calculating the maximum singular value of each sub-block to obtain a numerical matrix with the size (shown in the description); s5, converting the matrix into a 01 matrix; and S6, performing calculating according to the 01 matrix to obtain the hash value of the color image. According to the algorithm, each channel in the image can be regarded as a whole to be processed, so that the correlation among the channels is brought into full play, and the color image processing capability is improved. In addition, the invention further provides an image similarity measurement method basedon the algorithm, the ima