tag:blogger.com,1999:blog-8288194986820249216.post3960257076105633356..comments2024-03-22T05:09:17.789-07:00Comments on Abstract Heresies: Going backwardsJoe Marshallhttp://www.blogger.com/profile/03233353484280456977noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-8288194986820249216.post-59989159101216218112009-07-01T15:03:53.960-07:002009-07-01T15:03:53.960-07:00PS. As it was mentioned earlier you should try and...PS. As it was mentioned earlier you should try and experiment with median filters. They are non-linear (so they don't fit the Fourier aka frequency domain theory) but can be really useful for eliminating impulse noise without blurring the signal.jpchttps://www.blogger.com/profile/05403272030490907018noreply@blogger.comtag:blogger.com,1999:blog-8288194986820249216.post-15732325618775507312009-07-01T14:56:55.533-07:002009-07-01T14:56:55.533-07:00DFT is it's own inverse (the scalling may be d...DFT is it's own inverse (the scalling may be different depending on what scalling you chosen for forward DFT). [1]<br /><br />Taking inverse DFT of modified spectrum is problematic because of the implied periodicity of the signal (DFT computes as if the signal was wrapped around from end to the beginning). This can be worked around (look for explanations of the overlap-add method).<br /><br />For a very good introduction (or refreshment) to DSP try the book that can be downloaded at [2]. I have a deadtree copy on my bookshelf and I cannot overstate how great it is.<br /><br />[1]: http://en.wikipedia.org/wiki/Discrete_Fourier_transform#Definition<br /><br />[2]: http://dspguide.com/jpchttps://www.blogger.com/profile/05403272030490907018noreply@blogger.com