Image processing method based on threshold and homomorphic encryption

The invention provides an image processing method based on threshold and homomorphic encryption, and relates to the technical field of data encryption, comprising the following steps: a first terminal encrypts an original picture feature vector to obtain an owner feature vector; the server receives an owner feature vector, the owner feature vector comprises a plurality of owner feature components, and the owner feature components are stored in a plurality of memories respectively; the second terminal obtains a retrieval picture feature vector, obtains a retriever feature vector through public key encryption, and obtains a retrieval number according to the retriever feature vector; the server selects any two memories to extract owner feature components according to the retrieval number, and obtains an encrypted retrieval result by using the two owner feature components and the retriever feature vector; and the second terminal decrypts the encrypted retrieval result by using the private key to obtain a decrypte