Robust Image Hashing With Weighted Saliency Map and Laplacian Eigenmaps

Copy detection is crucial for protecting image copyright. This paper proposes a robust image hashing approach via Weighted Saliency Map (WSM) and Laplacian Eigenmaps (LE) (hereafter WSM-LE approach). An important contribution is the WSM construction via the edge map and the saliency map. As the WSM can indicate the interest regions of image, hash calculation based on WSM can provide robustness of our WSM-LE approach. Another contribution is the low-dimensional feature learning by the LE technique. As the LE technique can effectively learn the internal geometric relationships of image, the extracted low-dimensional features can improve discrimination of our WSM-LE approach. In addition, the low-dimensional features are treated as vectors and the vector distances are used to create a compact and encrypted hash. Numerous experiments and comparisons are conducted to confirm the effectiveness and superiority of our WSM-LE approach. The results indicate that our WSM-LE approach has excellent classification and copy detection performances than some baseline approaches.