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n-D Visualizer/Controls Options

n-D Visualizer/Controls Options

Select Options from the n-D Controls menu bar to access the n-D Class Controls dialog and to change various display options.

See the following sections:

Open the Class Controls Dialog


To access the n-D Class Controls dialog, select Options > Class Controls from the n-D Controls menu bar. For details, see Interact with Classes.

Add Annotation


To add an annotation to the n-D Visualizer window, select Options > Annotate Plot from the n-D Controls menu bar. You cannot add borders to the n-D Visualizer.

Plot Z Profiles


To open a plot window containing the spectrum of a point selected in the n-D Visualizer:

  1. Select Options > Z Profile from the n-D Controls menu bar. The Input File Associated with n-D Data dialog appears.
  2. Select the data file associated with the n-D data. Typically, this file is the reflectance or original data. If you select an input file with different spatial dimensions than the file used for input into the n-D Visualizer, you will be prompted to enter the x and y offsets that point to the n-D subset.
  3. Select from the following options:
    • To plot a Z Profile for the point nearest the cursor, middle-click in the n-D Visualizer plot window.
    • To add plots to the Z Profile plot window, right-click in the n-D Visualizer plot window. The Z Profile corresponding to the point you selected is added to the Z Profile plot window.
  4. When the Z Profile plot window is open, the selected file is automatically used to calculate the mean spectra when you select Options > Mean Class or Mean All from the n-D Controls menu bar.

Import Spectra


To import spectra from other sources such as spectral libraries:

  1. Select Options > Import Library Spectra from the n-D Controls menu bar. The n-D Visualizer Import Spectra dialog appears.
  2. The input spectra must be in the same space as the n-D input data (that is, MNF space).

    Note: To convert the spectra to MNF, select Transform > MNF Rotation > Apply Forward MNF to Spectra from the Toolbox, and use the statistics you saved when you ran the MNF on the original data.

  3. Drag spectra names from a Z Profile or Spectral Library plot window into the n-D Visualizer Import Spectra dialog, or select Import from the n-D Visualizer Import Spectra menu bar to import spectra from a spectral library, ROI, or ASCII file. For details, see Collect Endmember spectra.
  4. Click Apply. The Import Spectra Parameters dialog appears.
  5. Select from the following options to set the spectra parameters.
    • To edit a spectrum name, select the spectrum and make any changes in the Name field.
    • To edit the spectrum color, select the name and select a color from the Color button.
    • To plot the spectrum in the n-D Visualizer plot window, select the Show Spectrum check box.
  6. Click OK. The spectra appear in the n-D Visualizer as stars with labels. Note that some spectra may fall outside the current projection and will not be visible until you rotate the data.

Delete Spectra

To delete imported library spectra from the n-D Visualizer:

  1. Select Options > Delete Library Spectra from the n-D Controls menu bar.
  2. Select the spectra to delete.
  3. Click OK.

Edit Spectra Parameters

To change the color or name of imported library spectra and to turn spectra on or off in the n-D Visualizer:

  1. Select Options > Edit Library Spectra from the n-D Controls menu bar. The Import Spectra Parameters dialog appears.
  2. Select the spectra to edit.
  3. Edit the color, change the names, and turn the Show Spectrum check box on or off for the individual spectra.
  4. Click OK.

Plot Mean Spectra


To plot a mean spectrum for the current class:

  1. Select Options > Mean Class from the n-D Controls menu bar. Or, to plot the mean spectra for all the defined classes, select Options > Mean All. An Input File Associated with n-D Data dialog appears.
  2. Select the file to use when calculating the mean. Typically, this file contains reflectance data.

If a Z Profile window is active, the mean spectra are automatically extracted from the file opened in the Z Profile.

Clear Classes


To clear the currently selected class from the n-D Visualizer:

  1. Select Options > Clear Class from the n-D Controls menu bar, or right-click in the n-D Visualizer and select Clear Class. The currently selected class is defined by the Active Class label in the n-D Class Controls dialog.
  2. To clear all of the classes from the n-D Visualizer, select Options > Clear All from the n-D Controls menu bar, or right-click in the n-D Visualizer and select Clear All.

Export Classes to ROIs


After you have defined all desired classes, you can export their image pixel locations to ROIs, which you can then use as endmembers for classifications, Linear Spectral Unmixing, Matched Filtering, or other spectral mapping methods.

  1. To export the current class to an ROI, select Options > Export Class from the n-D Controls menu bar, or right-click in the n-D Visualizer and select Export Class.
  2. To export all of the classes defined in the n-D Visualizer to ROIs, select Options > Export All from the n-D Controls menu bar, or right-click in the n-D Visualizer and select Export All.

An ROI is created to match the spatial location of the corresponding image pixels, which you can use with the original reflectance image for extraction of endmembers and classification.

Each time you export n-D Visualizer classes, new ROIs are generated. For example, if you choose Export All twice, two identical ROIs are generated for each class. For this reason, you should consider waiting until you have selected all of the corners of the data cloud before selecting Export All.

Turn Axes On and Off


To turn the axes on or off in the n-D Visualizer:

  1. Select Options > Show Axes from the n-D Controls menu bar.
  2. Select Options > Show Axes again to turn off the axes.

Note: ENVI does not keep track of which classes have already been exported to ROIs. If a selected class is exported more than once, ENVI creates multiple (identical) ROIs.



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