The present invention detects the presence of a digital watermark in an image by selecting regions within the image having a high probability of containing the watermark. The image is examined to determine which regions of the image have characteristics indicating that there is a high probability that...http://www.google.com.tw/patents/US20020057823?utm_source=gb-gplus-share專利 US20020057823 - Watermark detection utilizing regions with higher probability of success