Thank you for your information. I have found fftw in the add-ons and it works well.
You suggets to me to look at JPEG compression. To what do you think? I have not found neither in Jwiki nor in the add-on. I have just found that but it is not in J even if it is practice! http://www.clubic.com/telecharger-fiche10615-the-jpeg-wizard.html But the link is in french! For the theory: JPEG in english: in Wikipedia http://en.wikipedia.org/wiki/JPEG Michel > > FFTW is provided as a J add-on (Windows only). > > > If you are interested in the DCT for image compression, I suggest you > look at JPEG compression: DCT is the algorithm that is used. > > Best wishes, > > John ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
