Archived posting to the Leica Users Group, 2004/09/25
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]It seems very odd to me that Leica is trying to eliminate the anit-aliasing filter. I distinctly remember my digital signal processing courses that state that before you sample an analog signal you have to limit the bandwidth with a filter to at least half the sampling frequence (and that would be if you had a perfect low-pass filter, you have to go lower for real-world filters.) Moire patterns would be the result because artifacts would be generated by digital sampling. I had a real-world example of this where we were measuring ion-acoustic waves in very low-density argon plasmas and got results that were really exciting - until the experimentalist realized he hadn't built-in the low-pass filter. When the filter was installed the "exciting" results vanished and things approached theory. Oh darn. But that wasn't with optical systems and maybe someone who's won the galactic institude prize for extreme cleverness has figured out how to avoid the artifacts. I sorta hope so....but I'm wary of free lunches. Adam On Thu, 01 Jul 2004 08:49:02 -0400, Dan C <bladman99@yahoo.ca> wrote: > The other article concerns the digital back for the R8/R9. They are aiming > for a December launch, but they seem to be having problems getting the > internal image processing software ready. Leica isn't happy with it. An > "anti-aliasing" filter isn't be used, and they appear to be having problems > solving the resultand moir? patterns visible is some images. But they are > also confident these problems will be solved. No sample images yet. > > -dan c.