Patent ID: 7653211
Filing Date: 2010-01-26
Classification: G06T,H04N

Abstract:
1. A digital watermark detection apparatus to detect the watermark information from an input image signal, comprising: a first transformation unit configured to obtain an orthogonal transformation image signal by subjecting one of an input image signal embedded with watermark information and a first accumulated signal obtained by accumulating the input image signal over a period of time to orthogonal transformation; a scaling unit configured to generate a scaled image signal by scaling the orthogonal transformation image signal; a complex addition unit configured to produce a complex addition signal by subjecting the orthogonal transformation image signal and the scaled image signal to complex addition; a second transformation unit configured to produce a transformation complex addition signal by subjecting the complex addition signal to orthogonal transformation or inverse orthogonal transformation; and an estimation unit configured to estimate the watermark information based on a peak which appears at one of the transformation complex addition signal and a second accumulated signal obtained by accumulating the transformation complex addition signal over a period.