pds4 viewer : display a spectral profile from a spectral cube.

[mmebsout]

To view an Array_3D_Spectrum data, the PDS4 viewer offers Table or Image options.
It would be nice to have a Plot option inside the Image visualisation to view a spectral representation of one pixel.

examples :

3 - a cube of dimension spatial_x/spatial_y/spectral viewed with frames of dimensions spatial_x/spatial_y
-> a button "view spectral pixel" would change the cursor to a cross and a selection of pixel would give a graph representation of array_value per spectral axis (frame index)

1 - a cube of dimension spatial_x/spatial_y/spectral viewed with frames of dimensions (spatial_y or spatial_x)/spectral

• a button "view spectral horizontal line" would change the cursor to an horizontal arrow and a selection of a pixel would give a graph representation or array_value per spectral axis.
  

####2 - similarily in vertical mode

3 - a cube of dimension spatial_x/spatial_y/spectral viewed with frames of dimensions spatial_x/spatial_y

-> a button "view spectral pixel" would change the cursor to a cross and a selection of pixel would give a graph representation of array_value per spectral axis (frame index)