loadRthData.m

% ***************************************************************************
% Copyright 2015 HeartVista Inc.  All rights reserved.
% Contact: HeartVista, Inc. <rthawk-info@heartvista.com>
%
% This file is part of the RTHawk system.
%
% $HEARTVISTA_BEGIN_LICENSE$
%
% THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF HEARTVISTA
% The copyright notice above does not evidence any
% actual or intended publication of such source code.
%
% $HEARTVISTA_END_LICENSE$
%
% ***************************************************************************
%
%
% loadRthData.m
% Read data and header from the file exported by RTHawk
% This can take several minutes if the files are big
%
%     input: fileName -- the name of the file to which data have
%                        been exported using RthReconImageExport.cpp
%     output: data -- the image data
%             header -- the image data header
%             kspace -- the acquisition trajectory (kx ky density
%                       for each sample)
%

function [data, header, kspace] = loadRthData(fileName)

% Open file
fip = fopen(fileName, 'r', 'l');
if (fip == -1)
  tt = sprintf('File %s not found\n', fileName);
  error(tt);
  return;
end;

% Check that this is an RTHawk file
[magic, count] = fread(fip, 4, 'char');
if (count ~= 4)
  tt = sprintf('Cannot read file format\n');
  error(tt);
  return;
end;

if (sum(magic' ~= ['H' 'O' 'C' 'T']))
	tt = sprintf('Invalid file format\n');
  error(tt);
	return;
end;

% Read version, It should be 1, 2, or 3
[version, count] = fread(fip, 1, 'int');
if (count ~= 1)
  tt = sprintf('Cannot read version\n');
  error(tt);
  return;
end;

header = struct();

i=1;
data = [];
kspace = [];
while(1)
    % Read number of (key, value) pairs contained in the header
    [hashcount, count] = fread(fip, 1, 'int');
    if (count ~= 1)
        fprintf(1,'Successfully read %d frames\n',i-1);
        break;
    end;

    % Read header
    for k=1:hashcount
        stringLength = fread(fip, 1, 'int');
        key = fread(fip, stringLength, '*char')';
        value = fread(fip, 1, 'double');
        header(i).(key) = value;
    end

    if (version >= 2)
        % Read kspace size
        [samples, count] = fread(fip, 1, 'int');
        if (count ~=1)
            tt = sprintf('Cannot read kspace size\n')
            error(tt);
            return;
        end;

        % Read kspace
	      kspace(:,:,i) = fread(fip, [1, samples], 'float');
    end


    if(isfield(header(i), 'dataSize'))
        dataSize = round(header(i).dataSize);
        % Read next block of data
        [tmpData, count] = fread(fip, [2,dataSize], 'float');
        if(count ~= 2*dataSize)
            fprintf(1,'End of file reached. Expected %d blocks of data but only read %d blocks.\n',dataSize,count);
            fprintf(1,'Successfully read %d frames\n',i-1);
            break;
        end;
        data(:,:,i) = tmpData;
    else
        % Read all remaining data
        [data, count] = fread(fip, [2,inf], 'float');

        % Print header
        header

        break;
    end

    i = i+1;
end