In praise of AA filters

Started Oct 23, 2013 | Discussions thread
John Sheehy
Forum ProPosts: 16,283
Like?
Re: Wait a minute: Foveon example not so aliased after all...
In reply to crames, Oct 27, 2013

crames wrote:

Take a look at the foveon example zoomed 300% with sinc interpolation. There is actually only a few small aliased patches, mostly in the upper left.

Huh?  I see moire in the right edge, second patch from bottom, the right bottom of the first full patch in the lower right corner, the patch just a little left and south of center, and I also see inconsistent rendering of the darker spots in the areas where the three-toned lines cross the other lines, due to luck of alignment.  This is a clearly aliased capture.  I don't see just fabric here; I see poor capture, which ruins the fabric.  Face it, we need cameras with a hell of a lot more pixels to properly record things like this.  Shortcuts do not work.

Foveon zoomed 300% with sinc interpolation

You can't really evaluate aliasing without doing some interpolation - has to do with the sampling theorem. If it goes away when you interpolate, it can't be aliasing.

What people often think is aliasing is really caused by the way the image is displayed, rather than the way it is captured.

Not in a 1:1 display; then there has to be a difference in capture for there to be a difference in output.  A converter does not randomly increase micro-contrast in some areas and decrease it in others.

Reply   Reply with quote   Complain
Post (hide subjects)Posted by
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark post MMy threads
Color scheme? Blue / Yellow