A scheme for censorship of sensitive image content with high-quality reconstruction ability

Multimedia files often contain fragments with sensitive content that should not be visible to everyone. Such content is usually censored prior to distribution. We propose a technique that allows to blur selected fragments of the image while retaining details necessary for original appearance reconstruction in the image itself. The information is retained by means of a digital watermark. The protected image can be viewed in ordinary viewers and a dedicated decoder is required for content restoration. The decoder ensures that only authorized recipients are able to see the protected fragments. We evaluate the proposed approach in terms of protection capacity and reconstruction quality also under lossy compression. The results show that high image quality is achievable and the proposed scheme might be beneficial for certain applications. Moderate complexity of the decoding process makes it feasible for real-time usage scenarios.