{'fraction_non_alphanumeric': 0.018475750577367205, 'fraction_numerical': 0.0, 'mean_word_length': 5.470149253731344, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Image watermarking with zero-mean patches

We describe a new technique for robust watermarking of digital images for copyright protection. The proposed technique involves modulating the image signal with random zero-mean patches at random locations, the randomness being determined by a pseudorandom number generator seeded with a public-key digital signature. Watermark verification is done using correlation measurements on a candidate image, and does not require the original image. The watermark is robust against a wide range of geometric manipulations and image processing. However; like other watermarking schemes that do not use any transformation-invariant domain for applying the watermark, our scheme also requires a registration search prior to detection. The search procedure, which can be made faster by retaining the original image, is also discussed.