[A complimentary Cc of this posting was sent to
Alfred Molon
<alfred_molon@yahoo.com>], who wrote in article <MPG.221838d7f379063f98b973@news.supernews.com>:
> To upsize images from 6-10 MP to 16MP which interpolation method
> delivers better results - Lanczos or Bicubic?
There are many Lanczos' (and I even heard that there are flavors of
bicubic - although I can imagine only 2). Any Lanczos' would be
slower than any bicubic. Which one is better MUST depend on how fuzzy
your image already is; I would expect that in most situations Lanczos'
would beat bicubic...
But I think a lot would depend on WHY you want to upsize... E.g., a
decent printer would know "the best" way to upscale to its native
resolution...
Alfred Molon wrote:
> To upsize images from 6-10 MP to 16MP which interpolation method
> delivers better results - Lanczos or Bicubic?
From my experience Sinc (Lanczos 3) in Gimp is visibly better than
Bicubic in Photoshop for upscaling. The reverse seems to apply for
downscaling - unless you like to see visible aliasing.
In article <1202593221.933094@ftpsrv1>, frederick says...
> From my experience Sinc (Lanczos 3) in Gimp is visibly better than
> Bicubic in Photoshop for upscaling. The reverse seems to apply for
> downscaling - unless you like to see visible aliasing.
I was thinking of perhaps using the Lanczos filter of the ImageMagick
command line utilities, to upsize images in a batch mode. Do you happen
to know which Lanczos filter ImageMagick uses for upsizing?
--
In article <fol69g$1925$1@agate.berkeley.edu>, Ilya Zakharevich says...
> Any Lanczos' would be
> slower than any bicubic.
That is not a problem.
> Which one is better MUST depend on how fuzzy
> your image already is;
Well, the image has the typical fuzzyness level of an image produced by
a digital camera.
> But I think a lot would depend on WHY you want to upsize...
Some stock agencies insist on receiving images in a resolution of 16MP
(which does not have to be the native resolution, i.e. upsizing is
explicitely allowed).
--
Alfred Molon wrote:
> In article <1202593221.933094@ftpsrv1>, frederick says...
>
>> From my experience Sinc (Lanczos 3) in Gimp is visibly better than
>> Bicubic in Photoshop for upscaling. The reverse seems to apply for
>> downscaling - unless you like to see visible aliasing.
>
> I was thinking of perhaps using the Lanczos filter of the ImageMagick
> command line utilities, to upsize images in a batch mode. Do you happen
> to know which Lanczos filter ImageMagick uses for upsizing?
No sorry - I don't. I guess you should just try it - the end result is
what counts...
I see with ImageMagick that anti-aliasing can be performed when
downsampling with Lanczos. That's a good idea - with Gimp set to use
Lanczos as default interpolation, it would be very handy to have some
anti-aliasing applied automatically when an image is downsampled.
On Sun, 10 Feb 2008 00:44:17 +0100, Alfred Molon wrote:
> In article <1202593221.933094@ftpsrv1>, frederick says...
>
>> From my experience Sinc (Lanczos 3) in Gimp is visibly better than
>> Bicubic in Photoshop for upscaling. The reverse seems to apply for
>> downscaling - unless you like to see visible aliasing.
>
> I was thinking of perhaps using the Lanczos filter of the ImageMagick
> command line utilities, to upsize images in a batch mode. Do you happen
> to know which Lanczos filter ImageMagick uses for upsizing?
I've always been amazed at the results when I accidently click on the
[FullScreen] button versus the [X] button when trying to close down an
ImageMagick display. It'll take a not-so-hot-to-begin-with web cam
image from 640x480 to 1272x995 _and seemingly make the image better at_
_the same time!_
Lanczos or Bicubic better for upsizing? 
Linear Mode
