Upon capturing a digital watermark-embedded print product by an image capturing device held by the hand of a user and extracting embedded information, the relative speed between the hand-held image capturing device and the print product changes, failing in extracting the embedded additional information. In an embodiment, the image capturing device performs continuous shooting for every small area to read the print product. A shoot image is analyzed to calculate the feature amount of the image. Information about an image capturing quality characteristic generated at the time of capturing the print product is estimated, and a change of the feature amount accompanying the image capturing quality characteristic is predicted based on the estimation result. A code indicated by the watermark is determined based on the calculation result and the prediction result.