Use the Build 3D Cube tool to take a multispectral file or hyperspectral file (which may be spatially and spectrally subsetted) and create an RGB image with the spectral slice of the top row and far-right column in a perspective view. The spectral slices are stretched and a user-selected color table is applied. The final image is a 3D, RGB, color-composite image cube. All of the intermediate processing occurs file-to-file, or in memory, depending on your preferences. (Temporary files created during the process are deleted after they are used).

  1. From the Toolbox, select Spectral > Build 3D Cube. The 3D Cube Input File dialog appears.
  2. Select an input file and perform optional spatial and spectral subsetting, then click OK. The 3D Cube RGB Face Input Bands dialog appears.
  3. Select the RGB bands to place on the face of the image cube by clicking on the desired bands.
  4. Click OK. The 3D Cube Parameters dialog appears.
  5. Select the color table for the side and top of the 3D cube from the list of standard ENVI/IDL color tables.

  6. Enter a value for Spectral Scale to apply a multiplier to the pixel dimensions of the side and top.

    Tip: A factor greater than 1.0 exaggerates the side and top dimensions of the cube by replicating the spectral profiles. This is particularly useful for image cubes that contain a small number of spectral bands.

  7. Enter a Border value to modify the number of border (background) pixels surrounding the output image.
  8. Select output to File or Memory.
  9. Click OK. ENVI adds the resulting output to the Layer Manager.