1.求MATLAB里imread这个函数的眼睛源码眼睛欢迎网页源码源代码
求MATLAB里imread这个函数的源代码
function [X, map, alpha] = imread(varargin)
[filename, format, extraArgs, msg] = parse_inputs(varargin{ :});
if (~isempty(msg))
error('MATLAB:imread:inputParsing', '%s', msg);
end
% Download remote file.
if (strfind(filename, '://'))
url = true;
if (~usejava('mwt'))
error('MATLAB:imread:noJava', 'Reading from a URL requires a Java Virtual Machine.')
end
try
filename = urlwrite(filename, tempname);
catch
error('MATLAB:imread:readURL', 'Can''t read URL "%s".', filename);
end
else
url = false;
end
if (isempty(format))
% The format was not specified explicitly.
% Verify that the file exists.
fid = fopen(filename, 'r');
if (fid == -1)
if ~isempty(dir(filename))
error('MATLAB:imread:fileOpen', ['Can''t open file "%s" for reading;\nyou' ...
' may not have read permission.'], ...
filename);
else
error('MATLAB:imread:fileOpen', 'File "%s" does not exist.', filename);
end
else
% File exists. Get full filename.
filename = fopen(fid);
fclose(fid);
end
% Try to determine the file type.
format = imftype(filename);
if (isempty(format))
error('MATLAB:imread:fileFormat', 'Unable to determine the file format.');
end
else
% The format was specified explicitly.
% Verify that the file exists.
fid = fopen(filename, 'r');
if (fid == -1)
% Couldn't open using the given filename; search for a
% file with an appropriate extension.
fmt_s = imformats(format);
if (isempty(fmt_s))
error('MATLAB:imread:fileFormat', ['Couldn''t find format %s in the format registry.' ...
' See "help imformats".'], format);
end
for p = 1:length(fmt_s.ext)
fid = fopen([filename '.' fmt_s.ext{ p}]);
if (fid ~= -1)
% The file was found. Don't continue searching.
break
end
end
end
if (fid == -1)
if ~isempty(dir(filename))
error('MATLAB:imread:fileOpen', ['Can''t open file "%s" for reading;\nyou' ...
' may not have read permission.'], ...
filename);
else
error('MATLAB:imread:fileOpen', 'File "%s" does not exist.', filename);
end
else
filename = fopen(fid);
fclose(fid);
end
end
% Get format details.
fmt_s = imformats(format);
% Verify that a read function exists
if (isempty(fmt_s.read))
error('MATLAB:imread:readFunctionRegistration', 'No reading function for format %s. See "help imformats".', ...
fmt_s.ext{ 1});
end
if ((fmt_s.alpha) && (nargout == 3))
% Use the alpha channel.
[X, map, alpha] = feval(fmt_s.read, filename, extraArgs{ :});
else
% Alpha channel is not requested or is not applicable.
alpha = [];
[X, map] = feval(fmt_s.read, filename, extraArgs{ :});
end
% Delete temporary file from Internet download.
if (url)
delete_download(filename);
end
%%%
%%% Function delete_download
%%%
function delete_download(filename)
try
delete(filename);
catch
warning('MATLAB:imread:tempFileDelete', 'Can''t delete temporary file "%s".', filename)
end
%%%
%%% Function parse_inputs
%%%
function [filename, format, extraArgs, msg] = ...
parse_inputs(varargin)
filename = '';
format = '';
extraArgs = { };
msg = '';
% Parse arguments based on their number.
switch(nargin)
case 0
% Not allowed.
msg = 'Too few input arguments.';
return;
case 1
% Filename only.
filename = varargin{ 1};
otherwise
% Filename and format or other arguments.
filename = varargin{ 1};
% Check whether second argument is a format.
if (ischar(varargin{ 2}))
fmt_s = imformats(varargin{ 2});
else
fmt_s = struct([]);
end
if (~isempty(fmt_s))
% The argument matches a format.
format = varargin{ 2};
extraArgs = varargin(3:end);
else
% The argument begins the format-specific parameters.
extraArgs = varargin(2:end);
end
end
