Effect of Locations of using High Boost Filtering on the Watermark Recovery in Spatial Domain Watermarking

Generally, High Boost filter is used to emphasize high frequency components representing the image details without eliminating low frequency components representing the basic form of the signal. The dissimilarity between the watermark and unwatermarked parts of the image are increased by this filter. Thus, watermark could be recovered significantly better by recovery algorithm. In this article, a comparison is taken place between the effects of different places of preforming High Boost filter on the reliability of the recovery methods in spatial domain image watermarking. This filter is convolved in two different places in the watermark extraction algorithm; before running the watermark extraction and before calculate the correlation in the middle of extraction. This article concentrate to conclude which of these places is more proper to convolve this filter. A classic correlation based method is used as a representative of spatial domain watermarking. Several experiment are done, to show which one of this places is more proper for preforming proposed filter.