ENVI格式数据由一个*.hdr的头文件和一个数据文件组成，我还没有在matlab中发现读取ENVI格式数据。借助于GOOGLE的帮助，我搜索到了一个由V. Guissard在 Apr 29 2004写成的freadenvi文件，调用格式如：[image,p,t] = freadenvi(fname)
但是用了这个函数之后，偶发现这个函数只能读取BSQ格式的数据，而且读出的数据是光谱维度不变，但是空间维进行了转置。因此，我对其进行了部分修改，使之能读取BSQ、BIL、BIP三种格式，读取来的数据是m*n*p三维数组，m表示行；n表示列；p表示波段数。
以下是经过修改后的freadenvi函数：
function [image,p,t,b] = freadenvi(fname)
% freadenvi - read envi image (V. Guissard, Apr 29 2004)
%
% Reads an image of ENVI standard type
% to a [col x line x band] MATLAB array
% image=freadenvi(fname)
% [image,p]=freadenvi(fname)
% [image,p,t]=freadenvi(fname)
% [image,p,t,b] = freadenvi(fname)
%
% INPUT :
%
% fname string giving the full pathname of the ENVI image to read.
%
% OUTPUT :
%
% image----------- c by l by b array containing the ENVI image values organised in
% c : cols, l : lines and b : bands.
% p 1 by 3 vector that contains (1) the nb of cols, (2) the number.
% of lines and (3) the number of bands of the opened image.
%
% t string describing the image data type string in MATLAB conventions.
% b string describing the image data interleave:bsq,bil or bip
%
% NOTE : freadenvi needs the corresponding image header file generated
% automatically by ENVI. The ENVI header file must have the same name
% as the ENVI image file + the '.hdf' exention.
% Revised by Hu Shunshi,2011.1.3
% can read bsq,bil and bip data interleave.
%%%%%%%%%%%%%

% Parameters initialization
elements={'samples ' 'lines ' 'bands ' 'data type ' 'interleave '};
d={'bit8' 'int16' 'int32' 'float32' 'float64' 'uint16' 'uint32' 'int64' 'uint64'};
interleave={'bsq' 'bil' 'bip'};
% Check user input
if ~ischar(fname)
error('fname should be a char string');
end


% Open ENVI header file to retreive s, l, b & d variables
rfid = fopen(strcat(fname,'.hdr'),'r');

% Check if the header file is correctely open
if rfid == -1
error('Input header file does not exist');
end;

% Read ENVI image header file and get p(1) : nb samples,
% p(2) : nb lines, p(3) : nb bands, t : data type and b:interleave
while 1
tline = fgetl(rfid);
if ~ischar(tline), break, end
[first,second]=strtok(tline,'=');

switch first
case elements(1)
[f,s]=strtok(second);
p(1)=str2num(s);
case elements(2)
[f,s]=strtok(second);
p(2)=str2num(s);
case elements(3)
[f,s]=strtok(second);
p(3)=str2num(s);
case elements(4)
[f,s]=strtok(second);
t=str2num(s);
switch t
case 1
t=d(1);
case 2
t=d(2);
case 3
t=d(3);
case 4
t=d(4);
case 5
t=d(5);
case 12
t=d(6);
case 13
t=d(7);
case 14
t=d(8);
case 15
t=d(9);
otherwise
error('Unknown image data type');
end
case elements(5)
[f,b]=strtok(second);
b=strtrim(b);
end
end
fclose(rfid);

t=t{1,1};
% Open the ENVI image and store it in the 'image' MATLAB array
disp([('Opening '),(num2str(p(1))),('cols x '),(num2str(p(2))),('lines x '),(num2str(p(3))),('bands')]);
disp([('of type '), (t), (' image...')]);
fid=fopen(fname);
image=fread(fid,t);

switch b
case interleave(1)
% bsq
image=reshape(image,[p(1),p(2),p(3)]);
for dimen=1:p(3)
image1(:,:,dimen)=image(:,:,dimen)';
end
image=image1;
case interleave(2)
% bil
image1=zeros(p(2),p(1),p(3));
count=1;
for row =1:p(2)
for dimen=1:p(3)
image1(row,:,dimen) =image((count-1)*p(1)+1:count*p(1));
count=count+1;
end
end
image=image1;
case interleave(3)
% bip
image1=zeros(p(2),p(1),p(3));
count=1;
for row=1:p(2)
for col=1:p(1)
image1(row,col,:)=image((count-1)*p(3)+1:count*p(3));
count=count+1;
end
end
image=image1;
otherwise
error('Unknown image data interleave');
end

fclose(fid);