function?data=read_ENVIimagefile?（imgfilename）
if?length（imgfilename）?>=4
????switch?strcmp（imgfilename（length（imgfilename）-3?:?end）‘.img‘）
????????case?0
????????????hdrfilename?=strcat（imgfilename‘.hdr‘）;
????????case?1
????????????hdrfilename?=strcat（imgfilename（1:（length（imgfilename）-4））‘.hdr‘）;
????end
else
????hdrfilename?=strcat（imgfilename‘.hdr‘）;
end

fid?=fopen（hdrfilename‘r‘）
info?=?fread（fid‘char=>char‘）;
info?=info‘;
fclose（fid）;
a=strfind（info‘samples?=?‘）;
b=length（‘samples?=?‘）;
c=strfind（info‘lines‘）;
samples?=[];
for?i?=a+b:c-1
????samples?=?[samplesinfo（i）];
end
samples?=?str2num（samples）;

a=strfind（info‘lines???=?‘）;
b=length（‘lines???=?‘）;
c=strfind（info‘bands‘）;
lines=[];
for?i=a+b:c-1
????lines=[linesinfo（i）];
end
lines?=str2num（lines）;

a=strfind（info‘bands???=?‘）;
b=length（‘bands???=?‘）;
c=strfind（info‘header?offset‘）;
bands=[];
for?i=a+b:c-1
????bands=[bandsinfo（i）];
end
bands?=str2num（bands）;

a=strfind（info‘data?type?=?‘）;
b=length（‘data?type?=