Apparatus and method for inserting/extracting nonblind watermarkusing feathers of digital media data

A device and a method for inserting/extracting non-blind watermark using feature of digital media data are provided to restore a watermark efficiently by searching host media data automatically with the feature, which is robust to deformation by watermarking, of the media data. An additional information database(300) stores additional watermark information, which is related to a watermark method, watermark data, a watermark inserter, or watermark strength of each media data stored in a media database(100). A watermark inserting module searches the additional watermark information from the address information database and inserts a watermark into host media data according to the searched additional watermark information when the host media data is selected among the media data stored in the media database. A feature extracting module(310) extracts feature used for identifying the media data from the watermarked media data(500). A feature searching module(320) searches the additional watermark information by using the extracted feature. A watermark extracting module(330) extracts the watermark from the watermarked media data by using the searched host media data(4) and additional watermark information(5).