# Configuration and the Preferences dialog

A variety of configuration options are available in the Preferences dialog, which is accessible from the Noise Ninja menu. These options affect the performance, behavior, and appearance of Noise Ninja.

## Profiles page

The Startup behavior group controls the automation of profile selection each time the plug-in user interface is launched. The Profile Policy combo box provides the following options:

- Auto-load profile based on EXIF: This will examine the EXIF data in the current image to identify the camera model, ISO, and other relevant attributes of the image. It will then attempt to the noise profile that best matches these attributes. If matching fails, then the Fallback policy will be applied. The matching process can be configured by clicking on the Set auto-loader criteria button. Note that the auto-load option is only useful if your images contain sufficient EXIF data. Most digital cameras today embed EXIF data in JPEG and RAW images. However, some manufacturers store important information like the ISO setting in a proprietary location where Photoshop and Noise Ninja can't find it.
- Invoke automatic profiler: The image is scanned for detail-free regions, and the noise in those regions is analyzed to construct a noise profile automatically. Note that, if you use this option, it can cause a delay each time the plug-in is invoked. For normal-sized images the delay will usually be only a few seconds, but the delay will increase for larger images.
- Use previous profile and settings: This will apply the noise profile and filter settings that were used the last time the plug-in was invoked. This setting can be useful if you are processing several images that were shot under the same conditions.
- Reset profile and settings: The profile and filter settings will be reset to default values.

The Startup behavior policy is overridden in the following situations:

- If the plug-in is invoked by the "Last Filter" command in Photoshop (that is, the plug-in is applied without displaying the user interface), then the previous profile and filters settings will be applied.
- If the plug-in is invoked by an action (an automated Photoshop macro), then the policies recorded in the action on the Action page of the plug-in will be used.

The Location and naming group includes options for the location of noise profiles and automatic profile naming.

- The Root directory specifies the folder that will contain noise profiles. The automatic profile loader will always look in this directory when it attempts to find matching profiles. You can share profiles with the standalone version of Noise Ninja by setting the root directory to the same one that is used by the standalone version.
- The Propose name when saving profile option, when enabled, will generate a file name automatically that summarizes key annotations of the profile. The names can be quite long and a little hard to read. It is not necessary to enable this option, because the automatic profile loader ignores the file name and instead relies on the annotations embedded within each profile. But this option can be useful when you have many profiles to keep track of.
- The Propose directory when saving profile option should normally be enabled if you intend to use the automatic profiler. When you save a profile, this option will automatically create and name folders that correspond to the camera manufacturer and camera model annotations in the profile. This ensures that the automatic profile loader will be able to locate the profiles later. If you try to create the folders yourself, you are more likely to make a typographical error that will prevent the profiles from being located by the auto loader.

## Filtering page

The Multiprocessing options allow noise removal to execute on more than one processor to accelerate computation. It requires that you have a computer with two or more processors, or a processor that supports hyperthreading. On a single-processor computer, you should choose "One thread", because extra threads only add overhead. On a dual-processor or hyperthreaded computer, four threads seems to result in the best utilization of the processors.

If you select Set Default Sharpening to Zero, the sharpening amount on the Filter page will be set to zero when the filter settings are reset or loaded from disk. You can still use the sharpening function by moving the slider to a nonzero value.

## Preview page

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The Preview Window Size option controls the dimensions of the preview window. A smaller preview will tend to update more quickly than a larger one. Also, if you have a low-resolution display, a smaller preview size will allow the plug-in dialog to fit better on the screen. If you try to choose a size that is too large for your screen, the window will be automatically resized to smaller dimensions.

The Update Mode option determines whether the preview is animated. If "Wait for Filter" is selected, the preview is updated all at once after the filter calculations have finished. The other options cause the preview to be updated in strips, with a dashed line indicating the amount of progress. The animation provides more obvious visual feedback, though some users find it distracting.

The Logging option determines where the log file is located. You should choose a location that has both read and write permissions. Each time Noise Ninja is invoked, whether normally or via an action, it writes an entry in the log file that indicates the image file name, what profile policy and filtering policies are in effect, what profile was selected, and other information. This can be useful for sanity-checking the behavior of a new action.