Compact and Robust Fingerprints Using DCT Coefficients of Key Blocks

In this paper, we present a novel fingerprinting method for image authentication, the fingerprint length of which is very short (only 81 bytes) and independent on image sizes. First, we extract features based on the block DCT coefficients of images, and binarize the feature map to get key blocks. Then we apply Principal Components Analysis (PCA) to the DCT Coefficients of key blocks. Finally, we take the quantized eigenvector matrix (9×9) as fingerprints. Experimental results show that the proposed method is discriminative, robust against compression, and sensitive to malicious modifications.