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load_untouch0_nii_hdr.m
200 lines (170 loc) · 8.1 KB
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load_untouch0_nii_hdr.m
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% internal function
% - Jimmy Shen (jimmy@rotman-baycrest.on.ca)
function hdr = load_nii_hdr(fileprefix, machine)
fn = sprintf('%s.hdr',fileprefix);
fid = fopen(fn,'r',machine);
if fid < 0,
msg = sprintf('Cannot open file %s.',fn);
error(msg);
else
fseek(fid,0,'bof');
hdr = read_header(fid);
fclose(fid);
end
return % load_nii_hdr
%---------------------------------------------------------------------
function [ dsr ] = read_header(fid)
% Original header structures
% struct dsr
% {
% struct header_key hk; /* 0 + 40 */
% struct image_dimension dime; /* 40 + 108 */
% struct data_history hist; /* 148 + 200 */
% }; /* total= 348 bytes*/
dsr.hk = header_key(fid);
dsr.dime = image_dimension(fid);
dsr.hist = data_history(fid);
return % read_header
%---------------------------------------------------------------------
function [ hk ] = header_key(fid)
fseek(fid,0,'bof');
% Original header structures
% struct header_key /* header key */
% { /* off + size */
% int sizeof_hdr /* 0 + 4 */
% char data_type[10]; /* 4 + 10 */
% char db_name[18]; /* 14 + 18 */
% int extents; /* 32 + 4 */
% short int session_error; /* 36 + 2 */
% char regular; /* 38 + 1 */
% char hkey_un0; /* 39 + 1 */
% }; /* total=40 bytes */
%
% int sizeof_header Should be 348.
% char regular Must be 'r' to indicate that all images and
% volumes are the same size.
v6 = version;
if str2num(v6(1))<6
directchar = '*char';
else
directchar = 'uchar=>char';
end
hk.sizeof_hdr = fread(fid, 1,'int32')'; % should be 348!
hk.data_type = deblank(fread(fid,10,directchar)');
hk.db_name = deblank(fread(fid,18,directchar)');
hk.extents = fread(fid, 1,'int32')';
hk.session_error = fread(fid, 1,'int16')';
hk.regular = fread(fid, 1,directchar)';
hk.hkey_un0 = fread(fid, 1,directchar)';
return % header_key
%---------------------------------------------------------------------
function [ dime ] = image_dimension(fid)
%struct image_dimension
% { /* off + size */
% short int dim[8]; /* 0 + 16 */
% /*
% dim[0] Number of dimensions in database; usually 4.
% dim[1] Image X dimension; number of *pixels* in an image row.
% dim[2] Image Y dimension; number of *pixel rows* in slice.
% dim[3] Volume Z dimension; number of *slices* in a volume.
% dim[4] Time points; number of volumes in database
% */
% char vox_units[4]; /* 16 + 4 */
% char cal_units[8]; /* 20 + 8 */
% short int unused1; /* 28 + 2 */
% short int datatype; /* 30 + 2 */
% short int bitpix; /* 32 + 2 */
% short int dim_un0; /* 34 + 2 */
% float pixdim[8]; /* 36 + 32 */
% /*
% pixdim[] specifies the voxel dimensions:
% pixdim[1] - voxel width, mm
% pixdim[2] - voxel height, mm
% pixdim[3] - slice thickness, mm
% pixdim[4] - volume timing, in msec
% ..etc
% */
% float vox_offset; /* 68 + 4 */
% float roi_scale; /* 72 + 4 */
% float funused1; /* 76 + 4 */
% float funused2; /* 80 + 4 */
% float cal_max; /* 84 + 4 */
% float cal_min; /* 88 + 4 */
% int compressed; /* 92 + 4 */
% int verified; /* 96 + 4 */
% int glmax; /* 100 + 4 */
% int glmin; /* 104 + 4 */
% }; /* total=108 bytes */
v6 = version;
if str2num(v6(1))<6
directchar = '*char';
else
directchar = 'uchar=>char';
end
dime.dim = fread(fid,8,'int16')';
dime.vox_units = deblank(fread(fid,4,directchar)');
dime.cal_units = deblank(fread(fid,8,directchar)');
dime.unused1 = fread(fid,1,'int16')';
dime.datatype = fread(fid,1,'int16')';
dime.bitpix = fread(fid,1,'int16')';
dime.dim_un0 = fread(fid,1,'int16')';
dime.pixdim = fread(fid,8,'float32')';
dime.vox_offset = fread(fid,1,'float32')';
dime.roi_scale = fread(fid,1,'float32')';
dime.funused1 = fread(fid,1,'float32')';
dime.funused2 = fread(fid,1,'float32')';
dime.cal_max = fread(fid,1,'float32')';
dime.cal_min = fread(fid,1,'float32')';
dime.compressed = fread(fid,1,'int32')';
dime.verified = fread(fid,1,'int32')';
dime.glmax = fread(fid,1,'int32')';
dime.glmin = fread(fid,1,'int32')';
return % image_dimension
%---------------------------------------------------------------------
function [ hist ] = data_history(fid)
%struct data_history
% { /* off + size */
% char descrip[80]; /* 0 + 80 */
% char aux_file[24]; /* 80 + 24 */
% char orient; /* 104 + 1 */
% char originator[10]; /* 105 + 10 */
% char generated[10]; /* 115 + 10 */
% char scannum[10]; /* 125 + 10 */
% char patient_id[10]; /* 135 + 10 */
% char exp_date[10]; /* 145 + 10 */
% char exp_time[10]; /* 155 + 10 */
% char hist_un0[3]; /* 165 + 3 */
% int views /* 168 + 4 */
% int vols_added; /* 172 + 4 */
% int start_field; /* 176 + 4 */
% int field_skip; /* 180 + 4 */
% int omax; /* 184 + 4 */
% int omin; /* 188 + 4 */
% int smax; /* 192 + 4 */
% int smin; /* 196 + 4 */
% }; /* total=200 bytes */
v6 = version;
if str2num(v6(1))<6
directchar = '*char';
else
directchar = 'uchar=>char';
end
hist.descrip = deblank(fread(fid,80,directchar)');
hist.aux_file = deblank(fread(fid,24,directchar)');
hist.orient = fread(fid, 1,'char')';
hist.originator = fread(fid, 5,'int16')';
hist.generated = deblank(fread(fid,10,directchar)');
hist.scannum = deblank(fread(fid,10,directchar)');
hist.patient_id = deblank(fread(fid,10,directchar)');
hist.exp_date = deblank(fread(fid,10,directchar)');
hist.exp_time = deblank(fread(fid,10,directchar)');
hist.hist_un0 = deblank(fread(fid, 3,directchar)');
hist.views = fread(fid, 1,'int32')';
hist.vols_added = fread(fid, 1,'int32')';
hist.start_field = fread(fid, 1,'int32')';
hist.field_skip = fread(fid, 1,'int32')';
hist.omax = fread(fid, 1,'int32')';
hist.omin = fread(fid, 1,'int32')';
hist.smax = fread(fid, 1,'int32')';
hist.smin = fread(fid, 1,'int32')';
return % data_history