Do we have an extraction code for difference expansion reversible watermarking?

I tried to implement DE on some images, but couldn't find in the code where is the image, that is being watermarked into the default image of ship. Secondly, if it's reversible watermarking there must be a code for detection of watermark and to extract it for

 http://www.mathworks.in/matlabcentral/fileexchange/25245-reversible-watermarking-by-difference-expansion/content/ian_Difference_Expansion.zip

This is the source from where I got the code for the algorithm.