The following MATLAB function will read the raw images in this archive, at least on a Macintosh computer.
function x = ReadRawImage(filename, width, height)
% x = ReadRawImage(filename, width, height)
%
% Read a RAW DATA format image written by IPLAB.
% The raw image data is written as a series of signed
% short integers in row first order.
%
% 2/24/97 jdt Wrote it.
% 12/29/15 dhb Change short to ushort in the fread.
% This seems to be needed now.
% 12/05/20 dhb Change ushort to uint16, which seems more explicit,
% and be explicit about big endian byte order in fopen.
% Examples:
%{
% Download (e.g.) the BearFruitGrayB image set and unpack.
% Change variable theImageDir to wherever you unpacked, and
% put this function into the same directory. Then execute this
% example to read a single image plane. Data come back as unsigned
% 16-bit integers. The image size differs for some of the other
% hyperspectral images.
theImageDir = '/Users/dhb/Desktop/BearFruitGrayB';
cd(theImageDir);
imSize = 2020;
imagePlane = ReadRawImage('400',imSize,imSize);
figure; clf; imshow(imagePlane/max(imagePlane(:)));
%}
% Open file
id = fopen(filename, 'r', 'b');
% Read in the data.
x = fread(id, [width,height], 'uint16')';
% Close file
fclose(id);