Secure image retrieval using pyramid histogram of oriented gradient descriptor

Secure Content Based Image Retrieval (CBIR) deals with retrieving similar images from an image database without revealing the contents of the query image. In the traditional CBIR, it is not practically possible to store large volumes of image database locally. Hence, image database has to be stored in a remote server. In this paper, the images are encrypted using double key RSA algorithm and are stored in the remote servers. The pyramid histogram of oriented gradients (PHoG) descriptor is used as feature for representing the images. The PHoG descriptor is computed on the original image and are encrypted and then stored in the remote server. The double key RSA ensures security and the attacker cannot effortlessly decrypt the images stored in the public server.