time   calls  line
                  1 function info = imfinfo(filename, format)
                  2 %IMFINFO Information about graphics file.
                  3 %   INFO = IMFINFO(FILENAME,FMT) returns a structure whose
                  4 %   fields contain information about an image in a graphics
                  5 %   file.  FILENAME is a string that specifies the name of the
                  6 %   graphics file, and FMT is a string that specifies the format
                  7 %   of the file.  The file must be in the current directory or in
                  8 %   a directory on the MATLAB path.  If IMFINFO cannot find a
                  9 %   file named FILENAME, it looks for a file named FILENAME.FMT.
                 10 %   
                 11 %   The possible values for FMT are contained in the file format
                 12 %   registry, which is accessed via the IMFORMATS command.
                 13 %
                 14 %   If FILENAME is a TIFF, HDF, ICO, GIF, or CUR file containing more
                 15 %   than one image, INFO is a structure array with one element for
                 16 %   each image in the file.  For example, INFO(3) would contain
                 17 %   information about the third image in the file.  
                 18 %
                 19 %   INFO = IMFINFO(FILENAME) attempts to infer the format of the
                 20 %   file from its content.
                 21 %
                 22 %   INFO = IMFINFO(URL,...) reads the image from an Internet URL.
                 23 %   The URL must include the protocol type (e.g., "http://").
                 24 %
                 25 %   The set of fields in INFO depends on the individual file and
                 26 %   its format.  However, the first nine fields are always the
                 27 %   same.  These common fields are:
                 28 %
                 29 %   Filename       A string containing the name of the file
                 30 %
                 31 %   FileModDate    A string containing the modification date of
                 32 %                  the file
                 33 %
                 34 %   FileSize       An integer indicating the size of the file in
                 35 %                  bytes
                 36 %
                 37 %   Format         A string containing the file format, as
                 38 %                  specified by FMT; for formats with more than one
                 39 %                  possible extension (e.g., JPEG and TIFF files),
                 40 %                  the first variant in the registry is returned
                 41 %
                 42 %   FormatVersion  A string or number specifying the file format
                 43 %                  version 
                 44 %
                 45 %   Width          An integer indicating the width of the image
                 46 %                  in pixels
                 47 %
                 48 %   Height         An integer indicating the height of the image
                 49 %                  in pixels
                 50 %
                 51 %   BitDepth       An integer indicating the number of bits per
                 52 %                  pixel 
                 53 %
                 54 %   ColorType      A string indicating the type of image; this could
                 55 %                  include, but is not limited to, 'truecolor' for a 
                 56 %                  truecolor (RGB) image, 'grayscale', for a grayscale 
                 57 %                  intensity image, or 'indexed' for an indexed image.
                 58 %
                 59 %   If FILENAME contains Exif tags (JPEG and TIFF only), then the INFO 
                 60 %   struct may also contain 'DigitalCamera' or 'GPSInfo' (global 
                 61 %   positioning system information) fields.
                 62 %
                 63 %   The value of the GIF format's 'DelayTime' field is given in hundredths
                 64 %   of seconds.
                 65 %
                 66 %   Example:
                 67 %     
                 68 %      info = imfinfo('ngc6543a.jpg');
                 69 %
                 70 %   See also IMREAD, IMWRITE, IMFORMATS.
                 71 
                 72 %   Copyright 1984-2008 The MathWorks, Inc.
                 73 %   $Revision: 1.1.6.14 $  $Date: 2009/11/09 16:27:13 $
                 74 
             4   75 error(nargchk(1, 2, nargin, 'struct')); 
                 76 
             4   77 info = []; 
                 78 
             4   79 if (~isNonEmptyString(filename)) 
                 80     error('MATLAB:imfinfo:badFilename', ...
                 81           'Filename must be a non-empty string.')
                 82 end
                 83 
                 84 % Download remote file.
             4   85 [isUrl, filename] = getFileFromURL(filename); 
                 86 
             4   87 if (nargin < 2) 
                 88   
                 89     % With 1 input argument, we must be able to open the file
                 90     % exactly as given.  Try it.
                 91     
             4   92     fid = fopen(filename, 'r'); 
                 93     
             4   94     if (fid == -1) 
                 95       
                 96         error('MATLAB:imfinfo:fileOpen', ...
                 97               'Unable to open file "%s" for reading.', filename);
                 98                
                 99     end
                100       
             4  101     filename = fopen(fid);  % Get the full pathname if not in pwd. 
             4  102     fclose(fid); 
                103   
                104     % Determine filetype from file.
  0.12       4  105     [format, fmt_s] = imftype(filename); 
                106     
             4  107     if (isempty(format)) 
                108       
                109         % Couldn't determine filetype.
             4  110         error('MATLAB:imfinfo:whatFormat', ... 
                111               'Unable to determine file format.');
                112         
                113     end
                114     
                115 else
                116   
                117     % The format was passed in.
                118     % Look for the format in the registry.
                119     fmt_s = imformats(format);
                120     
                121     if (isempty(fmt_s))
                122       
                123         % Format was not in registry.
                124         error('MATLAB:imfinfo:unknownFormat', ...
                125               'Could not find format "%s" in format registry.', format);
                126         
                127     end
                128 
                129     % Find the exact name of the file.
                130     fid = fopen(filename, 'r');
                131 
                132     if (fid == -1)
                133 
                134         % Since the user explicitly specified the format, see if we can find
                135         % the file using an extension.
                136     
                137         found = 0;
                138         
                139         for p = 1:length(fmt_s.ext)
                140           
                141             fid = fopen([filename '.' fmt_s.ext{p}], 'r');
                142             
                143             if (fid ~= -1)
                144               
                145                 % File was found.  Update filename.
                146                 found = 1;
                147                 
                148                 filename = fopen(fid);
                149                 fclose(fid);
                150                 
                151                 break;
                152                 
                153             end
                154             
                155         end
                156         
                157         % Check that some filename+format combination was found.
                158         if (~found)
                159             
                160             error('MATLAB:imfinfo:fileOpenWithExtension', ...
                161                   'Unable to open file "%s" for reading.', filename);
                162             
                163         end
                164         
                165     else
                166       
                167         % The file exists as passed in.  Get full pathname from file.
                168         filename = fopen(fid);
                169         fclose(fid);
                170         
                171     end
                172     
                173 end
                174 
                175 % Call info function from IMFORMATS on filename
                176 if (~isempty(fmt_s.info))
                177   
                178     info = feval(fmt_s.info, filename);
                179     
                180 else
                181   
                182      error('MATLAB:imfinfo:noInfoFunction', ...
                183            ['Format %s has no INFO function registered.  See', ...
                184             ' "help imformats".'], format);
                185         
                186 end
                187 
                188 
                189 % Delete temporary file from Internet download.
                190 if (isUrl)
                191     deleteDownload(filename);
                192 end