The Height Palette Editor applies a color palette to points in a linear, square root, or custom stretch. You can apply the color palette to all points in the project (full extents), or only to those that are visible in the Main window (view extents). You can save a custom palette you create to use with other ENVI LiDAR projects.

The Height Palette Editor is interactive, so the settings you choose in the dialog are immediately visible in the Main window as a preview. After you close the Height Palette Editor, you can use the Display Height Legend tool to view the color key.

To apply a height color palette:

  1. Click the Height Palette Editor button on the toolbar to open the Height Palette Editor dialog.
  2. Select one of the following to define the Height Range:
    • View Extents (default) applies the color palette only to points that are visible in the Main window. It spreads the palette between the minimum and maximum points within the view. The range is 0.000 (lowest point in view) to 1.000 (highest point in view).
    • Full Extents applies the color palette to all points in the project by assigning colors to specific heights throughout the full dataset. The range is the minimum and maximum heights of the project.
  3. Use the field or slider to enter a Minimum height value to apply to the palette. Points below this value will be assigned the same color as the minimum point. If the color palette is for View Extents, the default minimum is 0.00. For Full Extents, the default is the Min. Project Height value.
  4. Use the field or slider to enter a Maximum height value to apply to the palette. Points above this value will be assigned the same color as the maximum point. If the color palette is for View Extents, the default maximum is 1.00. For Full Extents, the default is the Max. Project Height value.
  5. If the color palette is for View Extents and the data has noise (such as, birds flew through the LiDAR collection area), you can enable the Clip View Extents (top 1%, bottom 1%) check box to clip the top and bottom points in the view so that they are not included in the color palette calculation.

  6. Manage the color palette in the Color Space table. The color bar to the left of the table shows the minimum to maximum range of the defined colors.

    • To edit an existing color, right-click the color row and select Edit Color, then select a color from the dialog that appears.
    • To add a new color, right-click an empty row and select Add Color, then select a color from the dialog that appears. If the rows between the last-defined color and the new color are unassigned, the rows between them will automatically be assigned colors, and height ranges will be assigned linearly.
    • To insert a new color between two existing colors, right click the color above the row to insert it and select Insert, then select a color from the dialog that appears.
    • To remove a color from the table, right-click on it and select Delete.
    • To move a color to a different order in the table, right-click on it and select Move Up or Move Down, accordingly.
    • To copy a color to another row in the table, right-click it and select Copy Color. Click the row where you want it to go, then right-click again and select Paste Color.
  7. To apply the color palette as a gradient, enable the Smooth Color Transition check box. The color bar shows the change, and the gradient is applied to the view.
  8. The default color palette is Custom Stretch. To apply a different stretch, select one of the following options from the drop-down list:
    • Linear Stretch applies the colors in a linear orientation.
    • Square Root Stretch applies the colors dynamically between the minimum and maximum ranges. This option allows for better color discrimination at the bottom of the color range.
  9. You can move the position of a color in the table to a different range, such as to highlight a particular height range. Select a color in the Color Space table and use the Position slider or field to specify the new position for that color. The color bar and the points in the Main window update to show the new position.

  10. To save a custom palette, click Save This Palette As and enter a name in the dialog box that appears.

    To apply a saved custom palette to a project, click Load Palette, and select the saved palette from the drop-down list.

  11. Click OK to apply the color palette.
  12. To view the height color legend, select Tools > Display Height Legend from the Toolbox. For details on the legend, see Display Height Legend.