Re: Gaussian blur kernels
Jon Watte <[email protected]>
| Newsgroups | gmane.games.devel.algorithms |
|---|---|
| Message-ID | <[email protected]> |
Nicholas "Indy" Ray wrote: > On Wed, Jul 15, 2009 at 4:46 PM, Joe Meenaghan<[email protected]> wrote: > >> Would the 5x5 over the lower res texture be approximately equivalent to a >> 9x9 at the higher res for example, or perhaps something along these lines? >> > > No... That isn't how it works; A downsample shares very little in > common with a blur. > > Actually, they are both low-pass filters, so downsampling-plus-upsampling is a form of blur. However, box filtering (the traditional downsampling function) isn't actually all that great at low-pass filtering, so it can generate aliasing, which a Gaussian filter does not. (AFAICR, the Gaussian filter kernel shares some properties with a sinc reconstruction kernel, and thus is "optimal" under certain conditions/assumptions, but details are hazy). Sincerely, jw -- Revenge is the most pointless and damaging of human desires. ------------------------------------------------------------------------------ Enter the BlackBerry Developer Challenge This is your chance to win up to $100,000 in prizes! For a limited time, vendors submitting new applications to BlackBerry App World(TM) will have the opportunity to enter the BlackBerry Developer Challenge. See full prize details at: http://p.sf.net/sfu/Challenge _______________________________________________ GDAlgorithms-list mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list Archives: http://sourceforge.net/mailarchive/forum.php?forum_name=gdalgorithms-list