Watermarking schemes evaluation
Abstract鈥擠igital watermarking has been presented as a solution to copy protection of multimedia objects and dozens of schemes and algorithms have been proposed. Two main problems seriously darken the future of this technology though.
Firstly, the large number of attacks and weaknesses which appear as fast as new algorithms are proposed, emphasizes the limits of this technology and in particu-lar the fact that it may not match users expectations.
Secondly, the requirements, tools and methodologies to assess the current technologies are almost non-existent. The lack of benchmarking of current algorithms is bla-tant. This confuses rights holders as well as software and hardware manufacturers and prevents them from using the solution appropriate to their needs. Indeed basing long-lived protection schemes on badly tested watermarking technology does not make sense.
nTIM PATRICK has been working professionally as a software architect and developer for nearly
25 years. By day he develops custom business applications in Visual Basic for small to medium-
sized organizations. He is a Microsoft Certified Solution Developer (MCSD). In April 2007,
Microsoft awarded Tim with its Most Valuable Professional (MVP) award for his work in sup-
porting and promoting Visual Basic and its community of users. Tim received his under-
graduate degree in computer science from Seattle Pacific University. You can contact him
through his web site, www.timaki.com.
The software is written in assembler, as it is very short and it need the speed in the main loop.
This is the heart of the synth. To be precise, it s in the 7 lines of assembler that makes up the main loop.
The rest of the code is the wavetables and the communication code.
Video-DVM is a very cheap DVM that shows how an output as complex as a videocomposite signal can be generated entirely in software: two I/O pins and three resistors are all the hardware required. Connected to any TV set it displays voltages, included max and min peaks, using both giant digits and an analog bar-display . A serial data output for computer data logging is provided, too.
As a programming language, C is rather like Pascal or Fortran.. Values are stored in variables.
Programs are structured by defining and calling functions. Program flow is controlled using loops, if
statements and function calls. Input and output can be directed to the terminal or to files. Related data
can be stored together in arrays or structures.
