I remember an image that looked less attractive after Neat Image had
removed the grain. What previously looked like shingles on a distant
building roof turned out to be nothing but grain. :-)
Chuck Norcutt
C.H.Ling wrote:
> ----- Original Message -----
> From: "Moose"
>> C.H.Ling wrote:
>>
>>> I remember I have seen someone mentioned here that resize does not reduce
>>> noise, I'm not sure if it is true.
>> I've certainly said here that it doesn't "necessarily" reduce noise. In
>> practice, my experience is that sometimes it does reduce apparent noise,
>> sometimes not, and occasionally, it seems to make it more objectionable.
>> I've no theoretical knowledge, but have noticed the effect of down
>> sampling on noise seems to vary with the nature of the noise and the
>> amount by which the image is being down sampled.
>>
>
> I have similar experience, sample down an image usually will not reduce the
> noise.
>
>> There are so many variables involved, especially with film scanning, tha
>> most of us have only a limited sample of the real world variation. You
>> and I both scan @ 4000 dpi, but with both different scanners and
>> different software. Even with the same piece of film, some
>> characteristics of both grain and scanner noise will differ.
>>
>
> I believe the light source made some difference, Nikon uses LED which
> enhance the grain more.
>
>> One difficulty with NR like this is that our eyes, at least mine, tend
>> to interpret the noise reduction as a loss of fine detail. The edges of
>> the grain tend to make things look sharper. In this case, even if a tiny
>> bit is lost, it doesn't matter, as the whole point is to prepare for
>> down sampling.
>>
>
> This is normal, long ago in the film age I heard people will found the image
> sharper for high speed film where there are stronger grain. For film images
> NR do reduce the details especially for the low contrast one and the fine
> texture on the clothes.
>
> C.H.Ling
>
>
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
|