batch process images

[kramerjm at gmail.com (James Kramer)]

On 4/9/06, James R. Van Zandt <jrvz at comcast.net> wrote:


> I tried this, and the only change I see is a slight loss of detail in
> some areas.
>
> However I don't know what I should be looking for.
>
> FWIW the two images are here:
>
> http://jrv.oddones.org/0225-104011.jpg    1931703
> http://jrv.oddones.org/0225-104011mod.jpg  672882
>
> I note the modified file is 1/3 the size of the original - apparently
> Gimp's compression with the default 85% setting is a lot more
> effective than the camera's.  OTOH that could account for the slight
> loss of detail.
>
>              - Jim Van Zandt
>
The loss in detail is the outcome of the noise reduction.  Noise can
be compared to grain in a film based photograph.  The filter reduces
the grain by smoothing the pixels.  It is also possible to increase
the sharpness of the images after the noise reduction.  The image that
you chose makes it difficult to see the noise.  Images with the sky or
some light solid surface will make it easier to detect.  If you
magnify the images you should see more of the effect.  Your camera may
do some of the filtering in it circuitry.
jay