Abstract: 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 a watermark signal can be detected in that region of the image. The regions that have a high probability that a watermark can be detected (in contrast to all regions of the image) are examined to find watermark data. Probability factors used to select detection regions include: requiring a minimum variance separation between detection blocks; requiring a minimum distance between overlapping blocks; segmenting the detection blocks into a first and second subset based on separate criteria; establishing a keep away zone to prevent selection of a detection block near an image's border; and selecting a detection block only after its neighbors met sufficient threshold requirements.