Each folder of example data set contains:

1.) An RGB composite image, made from Red, Green and Blue images from the full cube (.png format, can be opened in many programs).

2.) An ENVI header for the data cube with a filename ending in "dat.hdr" (see below, used to determine how to open data file)

3.) The ENVI data cube file with a filename ending in ".dat" (binary, see below, can be opened in ENVI or other hyperspectral software)

4.) A folder with each of the wavelength slices as a separate image, with the wavelength in the filename, in .png format, which can be opened in many programs

==========================================================================
Hyperspectral Data Cube Description.

The VNIR20 software produces ENVI format Hyperspectral data cubes.

An ENVI format data cube consists of two files:
	A header file (plain text) with a description of the format, dimensions and spectral bands in the image.
	A data file (binary) which consists of a series of images of the scene, at each wavelength called out in the header file.

Here is an example of a header file, with some explanation of its format: 

ENVI
description = {
  File Imported to ENVI}
samples = 114  (Number of Columns in the images)
lines   = 101  (Number of Rows in the images)
bands   = 39  (Number of images (one for each wavelength))
header offset = 0
file type = ENVI Standard
data type = 4  (Format of data (4=>32-bit floating point))
interleave = bsq  (Band Sequential Format; data are stored as a set of consecutive images)
sensor type = Unknown
byte order = 0  ("Little-Endian" (Intel) byte order in binary file)
wavelength units = Nanometers
wavelength = {
 460.000000, 465.000000, 470.000000, 475.000000, 480.000000, 485.000000,
 490.000000, 495.000000, 500.000000, 505.000000, 510.000000, 515.000000,
 520.000000, 525.000000, 530.000000, 535.000000, 540.000000, 545.000000,
 550.000000, 555.000000, 560.000000, 565.000000, 570.000000, 575.000000,
 580.000000, 585.000000, 590.000000, 595.000000, 600.000000, 605.000000,
 610.000000, 615.000000, 620.000000, 625.000000, 630.000000, 635.000000,
 640.000000, 645.000000, 650.000000}
(This last set of numbers is the wavelengths associated with each of the sequential images)

The header file is used by the ENVI program to determine how to interpret and display the data from the data file.  It can also be opened in a text editor, and used to determine the appropriate parameters for opening the data file as a raw image in an image processing program such as ImageJ (http://rsbweb.nih.gov/ij/).

=====================================================================
Opening a Hyperspectral image in ImageJ:

File->Import->Raw
Choose the file in the file window that pops up
An Import... window pops up, with fields to be filled in for the image to be opened.  The values in the Import... window can be taken from the header file:
Image type: 32-bit Real (from "data type = 4" in header)
Width: 114 pixels (comes from "samples = 114" in header) 
Height: 101 pixels (comes from "lines   = 101" in header)
Offset to first image: 0 bytes (comes from "header offset = 0" in header)
Number of images: 39 (comes from "bands   = 39" in header)
Gap between images: 0 bytes (comes from "interleave = bsq" in header)
unchecked: White is zero
CHECKED: Little-endian byte order (comes from "byte order = 0" in header)
unchecked: Open all files in folder
unchecked: Use virtual stack
->OK 
The 3D data cube will then show up in a window with a slider at the bottom to allow the user to step between wavelength slices in the "stack".  
Image->Adjust->Brighness/Contrast->Auto will likely make the images more clear.
