Block map implementation of difference expansion reversible watermarking

This paper investigates the block implementation of median edge detector (MED) based prediction error expansion reversible watermarking. Image is divided in overlapping blocks. A block is considered for data embedding only if all its pixels can be embedded. By embedding on blocks, the size of the location map is reduced. The block map implementation provides considerably better results than the classical location map implementation and rather similar to the histogram shifting ones. Experiments for different block sizes are provided.