# The Profile page

[Note: This page only describes the controls on the Profile page. Automatic profile loading, manual profile creation, profile annotations, and other topics related to profiles are discussed elsewhere. Click here for more in-depth information about profiles.]

The Profile page offers a graphical depiction of the current noise profile, along with functions for creating profiles automatically.

The Noise Index is an approximate measure of the total noise in a profile. Higher values indicate more total noise. Be careful using this to compare different cameras. For instance, small differences are probably not meaningful because they can be due to randomness in the sampling process. Also, noise can vary in "character" from one camera to another, and that isn't captured by the Noise Index.

The noise chart depicts the relative amount of noise associated with different colors and tones. Each cell in the chart denotes a single color. The leftmost bar in each cell represents the high-frequency component of the noise (i.e. fine noise). Each bar to the right represents increasingly coarse noise (i.e. lower spatial frequencies). A red dot underneath a bar means that that particular frequency was actually sampled; otherwise, the value was interpolated from other samples.

Beneath the chart is some text that displays the name of the current profile. It also indicates the origin of the profile -- for instance, whether it was automatically loaded, manually created, or auto-profiled from the current image.

The Profile Image button creates a profile automatically from the current image. It scans the image looking for uniform, detail-free regions, and it measures the noise in the selected regions. When it finishes, the selected regions are displayed in the main viewing window. You can use the Manual Profiling tool (located under the main window) to edit the remove individual selections or add new ones.

While the Profile Image function is convenient, be aware that it can be fooled by some textures and patterns. Also, some images contain too much detail in the highlights or shadows, so the automatic profiler might not be able to obtain good samples for those regions, and it will extrapolate from other samples. It is a good idea to examine the selections made by the automatic profiler and see if they look reasonable.

The Profile Chart button is similar to the Profile Image button, but it is designed to be used with a special profiling target, or calibration chart. The target is included with the Noise Ninja distribution in a JPEG file named calibration_chart.jpg. See "Profiling your camera or scanner" to learn more about using the profiling chart. Note that the Profile Chart buttons discards redundant selections (that is, those that are similar in color and tone to other selections). So, while it might appear to miss some squares in the chart, chances are that it evaluated them decided that they added no useful information.

The Reset button clears the current noise profile and any selections.