% internal function % - Jimmy Shen (jimmy@rotman-baycrest.on.ca) function save_nii_hdr(hdr, fid) if ~isequal(hdr.hk.sizeof_hdr,348), error('hdr.hk.sizeof_hdr must be 348.'); end write_header(hdr, fid); return; % save_nii_hdr %--------------------------------------------------------------------- function write_header(hdr, fid) % Original header structures % struct dsr /* dsr = hdr */ % { % struct header_key hk; /* 0 + 40 */ % struct image_dimension dime; /* 40 + 108 */ % struct data_history hist; /* 148 + 200 */ % }; /* total= 348 bytes*/ header_key(fid, hdr.hk); image_dimension(fid, hdr.dime); data_history(fid, hdr.hist); % check the file size is 348 bytes % fbytes = ftell(fid); if ~isequal(fbytes,348), msg = sprintf('Header size is not 348 bytes.'); warning(msg); end return; % write_header %--------------------------------------------------------------------- function header_key(fid, hk) 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 */ fwrite(fid, hk.sizeof_hdr(1), 'int32'); % must be 348. % data_type = sprintf('%-10s',hk.data_type); % ensure it is 10 chars from left % fwrite(fid, data_type(1:10), 'uchar'); pad = zeros(1, 10-length(hk.data_type)); hk.data_type = [hk.data_type char(pad)]; fwrite(fid, hk.data_type(1:10), 'uchar'); % db_name = sprintf('%-18s', hk.db_name); % ensure it is 18 chars from left % fwrite(fid, db_name(1:18), 'uchar'); pad = zeros(1, 18-length(hk.db_name)); hk.db_name = [hk.db_name char(pad)]; fwrite(fid, hk.db_name(1:18), 'uchar'); fwrite(fid, hk.extents(1), 'int32'); fwrite(fid, hk.session_error(1), 'int16'); fwrite(fid, hk.regular(1), 'uchar'); fwrite(fid, hk.hkey_un0(1), 'uchar'); return; % header_key %--------------------------------------------------------------------- function image_dimension(fid, dime) %struct image_dimension % { /* off + size */ % short int dim[8]; /* 0 + 16 */ % 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 % pixdim[2] - voxel height % pixdim[3] - interslice distance % ..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 */ fwrite(fid, dime.dim(1:8), 'int16'); pad = zeros(1, 4-length(dime.vox_units)); dime.vox_units = [dime.vox_units char(pad)]; fwrite(fid, dime.vox_units(1:4), 'uchar'); pad = zeros(1, 8-length(dime.cal_units)); dime.cal_units = [dime.cal_units char(pad)]; fwrite(fid, dime.cal_units(1:8), 'uchar'); fwrite(fid, dime.unused1(1), 'int16'); fwrite(fid, dime.datatype(1), 'int16'); fwrite(fid, dime.bitpix(1), 'int16'); fwrite(fid, dime.dim_un0(1), 'int16'); fwrite(fid, dime.pixdim(1:8), 'float32'); fwrite(fid, dime.vox_offset(1), 'float32'); fwrite(fid, dime.roi_scale(1), 'float32'); fwrite(fid, dime.funused1(1), 'float32'); fwrite(fid, dime.funused2(1), 'float32'); fwrite(fid, dime.cal_max(1), 'float32'); fwrite(fid, dime.cal_min(1), 'float32'); fwrite(fid, dime.compressed(1), 'int32'); fwrite(fid, dime.verified(1), 'int32'); fwrite(fid, dime.glmax(1), 'int32'); fwrite(fid, dime.glmin(1), 'int32'); return; % image_dimension %--------------------------------------------------------------------- function data_history(fid, hist) % Original header structures - ANALYZE 7.5 %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 */ % descrip = sprintf('%-80s', hist.descrip); % 80 chars from left % fwrite(fid, descrip(1:80), 'uchar'); pad = zeros(1, 80-length(hist.descrip)); hist.descrip = [hist.descrip char(pad)]; fwrite(fid, hist.descrip(1:80), 'uchar'); % aux_file = sprintf('%-24s', hist.aux_file); % 24 chars from left % fwrite(fid, aux_file(1:24), 'uchar'); pad = zeros(1, 24-length(hist.aux_file)); hist.aux_file = [hist.aux_file char(pad)]; fwrite(fid, hist.aux_file(1:24), 'uchar'); fwrite(fid, hist.orient(1), 'uchar'); fwrite(fid, hist.originator(1:5), 'int16'); pad = zeros(1, 10-length(hist.generated)); hist.generated = [hist.generated char(pad)]; fwrite(fid, hist.generated(1:10), 'uchar'); pad = zeros(1, 10-length(hist.scannum)); hist.scannum = [hist.scannum char(pad)]; fwrite(fid, hist.scannum(1:10), 'uchar'); pad = zeros(1, 10-length(hist.patient_id)); hist.patient_id = [hist.patient_id char(pad)]; fwrite(fid, hist.patient_id(1:10), 'uchar'); pad = zeros(1, 10-length(hist.exp_date)); hist.exp_date = [hist.exp_date char(pad)]; fwrite(fid, hist.exp_date(1:10), 'uchar'); pad = zeros(1, 10-length(hist.exp_time)); hist.exp_time = [hist.exp_time char(pad)]; fwrite(fid, hist.exp_time(1:10), 'uchar'); pad = zeros(1, 3-length(hist.hist_un0)); hist.hist_un0 = [hist.hist_un0 char(pad)]; fwrite(fid, hist.hist_un0(1:3), 'uchar'); fwrite(fid, hist.views(1), 'int32'); fwrite(fid, hist.vols_added(1), 'int32'); fwrite(fid, hist.start_field(1),'int32'); fwrite(fid, hist.field_skip(1), 'int32'); fwrite(fid, hist.omax(1), 'int32'); fwrite(fid, hist.omin(1), 'int32'); fwrite(fid, hist.smax(1), 'int32'); fwrite(fid, hist.smin(1), 'int32'); return; % data_history