% raw_image.m  -  plot raw data for a single echo from a Pfile
%
% Marquette University,   Milwaukee, WI  USA
% Copyright 2002, 2003, 2016, 2018 - All rights reserved.
% Author: Fred J. Frigo
%
%  - updated for 11.0 Pfile format
%  - updated for 12.0 Pfile format
%  - updated for 25.0 & 26.0 Pfile format 
%

function raw_image( pfile )


% Check to see if pfile name was passed in
if ( nargin == 0 )
   % Enter name of Pfile
   [fname, pname] = uigetfile('*.*', 'Select Pfile');
   pfile = strcat(pname, fname);
end
i = sqrt(-1);

% Open Pfile to read reference scan data.
fid = fopen(pfile,'r', 'ieee-be');
if fid == -1
    err_msg = sprintf('Unable to locate Pfile %s', pfile)
    return;
end

% Determine size of Pfile header based on Rev number
status = fseek(fid, 0, 'bof');
[f_hdr_value, count] = fread(fid, 1, 'real*4');
rdbm_rev_num = f_hdr_value(1);
if( rdbm_rev_num == 7.0 )
    pfile_header_size = 39984;  % LX
elseif ( rdbm_rev_num == 8.0 )
    pfile_header_size = 60464;  % Cardiac / MGD
elseif (( rdbm_rev_num > 5.0 ) && (rdbm_rev_num < 6.0)) 
    pfile_header_size = 39940;  % Signa 5.5
else
    % In 11.0 (ME2) the header and data are stored as little-endian
    fclose(fid);
    fid = fopen(pfile,'r', 'ieee-le');
    status = fseek(fid, 0, 'bof');
    [f_hdr_value, count] = fread(fid, 1, 'real*4');
    rdbm_rev_num = f_hdr_value(1);
    if (rdbm_rev_num == 9.0)  % 11.0 product release
        pfile_header_size= 61464;
    elseif (rdbm_rev_num == 11.0)  % 12.0 product release
        pfile_header_size= 66072;
    elseif (rdbm_rev_num > 11.0) & (rdbm_rev_num < 26.0)  
        % For 14.0 to 25.0 Pfile header size can be found here
        status = fseek(fid, 1468, 'bof');
        pfile_header_size = fread(fid,1,'integer*4');   
        status = fseek(fid, 1508, 'bof');
        prescan_offset = fread(fid,1,'integer*4');
    elseif ( rdbm_rev_num >= 26.0) & (rdbm_rev_num < 100.0)  % 26.0 to ??
        % For 26.0 Pfile header size moved to location just after rev num
        status = fseek(fid, 4, 'bof');
        pfile_header_size = fread(fid,1,'integer*4');
        status = fseek(fid, 44, 'bof');
        prescan_offset = fread(fid,1,'integer*4');
    else
        err_msg = sprintf('Invalid Pfile header revision: %f', rdbm_rev_num )
        return;
    end
end  
 
% Read header information
if (rdbm_rev_num < 26.0 )
    status = fseek(fid, 0, 'bof');
else
    status = fseek(fid, 76, 'bof'); % skip 76 bytes of data added for 26.0
end
[hdr_value, count] = fread(fid, 102, 'integer*2');
npasses = hdr_value(33);
nslices = hdr_value(35);
nechoes = hdr_value(36);
nframes = hdr_value(38);
point_size = hdr_value(42);
da_xres = hdr_value(52);
da_yres = hdr_value(53);
rc_xres = hdr_value(54);
rc_yres = hdr_value(55);
start_recv = hdr_value(101); % not used for 25.0 & greater
stop_recv = hdr_value(102);

% Determine number of slices in this Pfile:  this does not work for all cases.
slices_in_pass = nslices/npasses;

% Compute size (in bytes) of each frame, echo and slice
data_elements = da_xres*2*(da_yres-1);
frame_size = da_xres*2*point_size;
echo_size = frame_size*da_yres;
slice_size = echo_size*nechoes;
mslice_size = slice_size*slices_in_pass;

% For 24.0 and earlier - nreceivers is determined as follows
if (rdbm_rev_num < 25.0)
    nreceivers = (stop_recv - start_recv) + 1;
else % For 25.0 and later - compute nreceivers from number of slices
    status = fseek(fid, 0, 'eof');
    pfile_size = ftell(fid);
    pass_size = (pfile_size - pfile_header_size)/nslices;
    nreceivers = pass_size/mslice_size;
end

for k = 1:1000		% give a large number 1000 to loop forever
    
  % Enter slice number to plot
  my_slice = 1;
  if ( slices_in_pass > 1 )
      slice_msg = sprintf('Enter the slice number: [1..%d]',slices_in_pass); 
      my_slice = input(slice_msg);
      if (my_slice > slices_in_pass)
          err_msg = sprintf('Invalid number of slices. Slice number set to 1.')
          my_slice = 1;
      end
  end
  
  % Enter echo number to plot
  my_echo = 1;
  if ( nechoes > 1 )
      echo_msg = sprintf('Enter the echo number: [1..%d]',nechoes);
      my_echo = input(echo_msg);
      if (my_echo > nechoes )
          err_msg = sprintf('Invalid echo number. Echo number set to 1.')
          my_echo = 1;
      end
  end
  
  % Enter receiver number to plot
  my_receiver = 1;
  if ( nreceivers > 1 )
      recv_msg = sprintf('Enter the receiver number: [1..%d]',nreceivers);
      my_receiver = input(recv_msg);
      if (my_receiver > nreceivers)
          err_msg = sprintf('Invalid receiver number. Receiver number set to 1.')
          my_receiver = 1;
      end      
  end


  % Compute offset in bytes to start of frame.  (skip baseline view)
  file_offset = pfile_header_size + ((my_receiver - 1)*mslice_size) + ...
                      + ((my_slice -1)*slice_size) + ...
                      + ((my_echo-1)*echo_size) + ...
                      + (frame_size);
  
  status = fseek(fid, file_offset, 'bof');

  % read data: point_size = 2 means 16 bit data, point_size = 4 means EDR )
  if (point_size == 2 )
      [raw_data, count] = fread(fid, data_elements, 'int16');
  else
      [raw_data, count] = fread(fid, data_elements, 'int32');
  end

  %frame_data = zeros(da_xres);
  for j = 1:(da_yres -1)
     row_offset = (j-1)*da_xres*2;
     for m = 1:da_xres
        frame_data(j,m) = raw_data( ((2*m)-1) + row_offset) + i*raw_data((2*m) + row_offset);
     end
  end
  
  figure(k);
  imagesc( abs(frame_data));
  title(sprintf('Magnitude of Raw Data, slice %d, recv %d, echo %d', my_slice, my_receiver, my_echo));

  % check to see if we should quit
  quit_answer = input('Press Enter to continue, "q" to quit:', 's');
  if ( size( quit_answer ) > 0 )
     if (quit_answer == 'q')
         break;
     end
  end
  
end
fclose(fid);