90 Technical Issues: Killing the Gremlins
Another tricky issue can be that noise is often only visible in part
of the image, say, in the shadows or the sky. In Photoshop, there are
a number of ways to make sure that noise reduction is applied only
to those parts of the image that really need it- Quick mask. In Photoshop, use the quick mask tool and paint over areas you don’t
want noise reduction to impact before running the noise-reduction software. This is
fast and effective, but you have to judge in advance which areas to exclude from
noise reduction. - Selection. Use the lasso tool to do the same job as Quick mask; then feather the
selection before running noise reduction. - History brush. After you have run your noise-reduction software, select a history
state from the time immediately before you ran the software, and use the history
brush on any areas where too much detail has been lost. You can build up the effect
FIGURE 5.10 The Noise Ninja Photoshop plug-in profi le window.