Neat Image user guide / Filtration
process details
Stage II. Prepare a device noise profile
Use the Device Noise Profile tab in the Filtration
Job Editor:
To filter the input image, Neat Image needs to know the characteristics of
noise produced by the image acquisition device (digital camera, scanner, etc.)
that the image comes from. The noise characteristics of a device working in
certain mode are stored in a device noise profile.
There are several ways to get a device noise profile that suits the input image:
- To build a new profile using the input image or a specially prepared test
image;
- To automatically select the most suitable device noise profile from a ready-made
set of profiles using the automatic Profile Matcher;
- To manually select a suitable profile from a ready-made set of profiles
using their descriptions or file names.
The first option is often the easiest one provided the input image contains
uniform featureless image areas that contain noise but no visible or important
details. Neat Image can automatically find such image areas and analyze noise
in there to build a noise profile of the image. When there are featureless areas
in the image that can be analyzed, this way of preparing a noise profile is
the most accurate.
The last two options are available once you have a ready-made set of profiles.
You may find free sets of profiles for your imaging device(s) in:
- Profiles section
of Neat Image web page;
- Device noise
profiles section of Neat Image community forum;
- Other digital imaging forums and web pages from users of Neat Image.
If you cannot find a ready-made set of profiles, then you can easily build
profiles yourself. Moreover, please be aware that using ready-made profiles
built by other people may produce less than optimal results with your images
because of possible slight differences in noise properties of cameras (scanners)
as well as due to different imaging processing workflows used. Therefore, we
advise to use ready-made noise profile built by others only as a starting point
to learn how to use Neat Image. To achieve the best results consider building
your own profiles.
You can build a set of profiles for different device modes or just one profile
to process one image. See the Device
noise profiles section for detailed instructions.
Once you have a set of profiles for different modes of your imaging device,
you can (automatically or manually) select a profile that matches the input
image. Or if you have just built a singe profile specifically for the input
image, then you can just use it to process the image in the Stages III-V.
To build a new profile using the input image
- Click
(the Auto Profile
with Regular Image button) on the toolbar, or select the Profile
| Auto Profile with Regular Image menu item, or press F2.
Neat Image will show the image area selected for analysis (see blue selection
box in the image viewer; blue color is an indication of automatic selection)
and will analyze it automatically.
In difficult cases, Neat Image may have trouble with finding a uniform featureless
area in the input image. You will notice that the selected area, for example,
will contain some important image details. In such a case, just move the selection
(or draw a new one) to an area that does not contain any image details and
click the same Auto Profile with Regular Image button
again.
If you see that the area selected for analysis is indeed uniform and featureless,
then you can be sure that noise analysis and resulting noise profile is accurate.
In this case, consider the noise profile ready and proceed to Stage
III. Adjust filter settings.
To automatically select matching noise profile from
the set
- Click
(the Profile
matcher button) or select the Profile | Open Best
Matching Profile menu item.
The automatic Profile Matcher uses the EXIF data
fields of the input image to select the device noise profile that best matches
the device mode of the image. The device noise profile is selected in a set
of profiles stored in a special folder (and its subfolders) specified in the
application options.
See Profile
matching options for more details about the following profile matching options:
Matching device noise profile folder, Matching
parameters priorities and Auto match on image open.
To manually select noise profile from the set
- Click
(the Open device
noise profile… button, blue disk) in the Device Noise
Profile box or select the Profile | Open…
menu item. In the Open device noise profile dialog
box, you can specify the name of the device noise to be opened.
or
- lect a profile using the popup menu: click on the button on the right side
of the profile name shown in the top part of the Device
Noise Profile box, and select a profile from the popup menu (if there
is no popup menu, check the Folder options).
When selecting a profile that matches the device mode of the input image,
use the profile file names and folder structure to guide your search. See
Preparing
profile set for different device modes: Stage III. Structuring profile set
for more information on structuring the profile sets.
Stage I :: Stage II :: Stage
III :: Stage IV
:: Stage V