niftiwrite で画像タグ情報を編集​し書き込みたいとき，​エラーが出て出力でき​ません．

function metadata = niftiinfo(filename) %NIFTIINFO Read metadata from NIfTI file. % METADATA = NIFTIINFO(FILENAME) reads the header of the NIfTI file named % in the string or character vector FILENAME and returns all its contents % in a MATLAB structure called METADATA. If the file extension is not % specified, NIFTIINFO looks for a '.nii' file or its gzipped version % (with extension '.nii.gz'). If that is not found, it looks for a '.hdr' % file or its gzipped version (with extension '.hdr.gz'), and then a % '.img' file or its gzipped version (with extension '.img.gz'). If it % cannot find any of these files, NIFTIINFO returns an error. % % References: % ----------- % [1] Cox, R.W., Ashburner, J., Breman, H., Fissell, K., Haselgrove, C., % Holmes, C.J., Lancaster, J.L., Rex, D.E., Smith, S.M., Woodward, J.B. % and Strother, S.C., 2004. A (sort of) new image data format standard: % Nifti-1. Neuroimage, 22, p.e1440. % % Example 1 % --------- % %Viewing metadata fields from a NIfTI header file. % % % Load metadata from 'brain.nii'. % info = niftiinfo('brain.nii'); % % % Display the pixel dimensions of this file % info.PixelDimensions % % % Display the raw header content % info.raw % % % Display the intent code from the raw structure % info.raw.intent_code % % See also NIFTIREAD, NIFTIWRITE. % Copyright 2016-2017 The MathWorks, Inc. narginchk(1,1); filename = matlab.images.internal.stringToChar(filename); NF = images.internal.nifti.niftiFile(filename); fileDetails = dir(NF.HeaderFileName); metadata.Filename = fullfile(fileDetails.folder, fileDetails.name); metadata.Filemoddate = fileDetails.date; metadata.Filesize = fileDetails.bytes; NV = images.internal.nifti.niftiImage(NF.FileWithHeader); % Get the simplified structure from niftiImage. simpleStruct = NV.simplifyStruct(); % Copy simplified fields into metadata. fields = fieldnames(simpleStruct); for i = 1:numel(fields) metadata.(fields{i}) = simpleStruct.(fields{i}); end % Finally. append the raw struct to fileInfo. metadata.raw = NV.header; end

function niftiwrite(V, filename, varargin) %NIFTIWRITE Write images as NIfTI files. % NIFTIWRITE(V, FILENAME) writes a '.nii' file using the image data from % V. By default, NIFTIWRITE creates a 'combined' NIfTI file that contains % both metadata and volumetric data, giving it the '.nii' file extension. % NIFTIWRITE populates the file metadata using appropriate default values % and volume properties like size and data type. % % NIFTIWRITE(V, FILENAME, METADATA) writes a '.nii' file using the image % data from V and metadata from METADATA. NIFTIWRITE creates a 'combined' % NIFTI file, giving it the file extension '.nii'. If the metadata does % not match the image contents and size, NIFTIWRITE returns an error. % % NIFTIWRITE(____, Name, Value) writes a '.nii' file using options % specified in the Name Value pairs, described below. % % Optional Name-Value parameters include: % % 'Combined' - true (default) or false. If true, NIFTIWRITE % creates one file with the file extension '.nii'. % If false, NIFTIWRITE creates two files. One file % contains metadata and has the file extension % '.hdr'. The other files contains the volumetric % data and has the file extension '.img'. % NIFTIWRITE uses the file name you specified in % FILENAME for both files. % % 'Compressed' - false(default) or true. If true, NIFTIWRITE % compresses the generated file (or files) using % gzip encoding, giving the file the .gz file % extension as well as the NIFTI file extension. % % 'Endian' - 'little' (default) or 'big'. % Controls the endianness of the data NIFTIWRITE % writes to the file. % % 'Version' - 'NIfTI1' or 'NIfTI2'. Specifies the NIfTI format % the data is to be written in. Default value % depends on the maximum value of the dimensions % of the volumetric data. The default value is % 'NIfTI1' unless the maximum size in any % dimension is more than 32767. % % References: % ----------- % [1] Cox, R.W., Ashburner, J., Breman, H., Fissell, K., Haselgrove, C., % Holmes, C.J., Lancaster, J.L., Rex, D.E., Smith, S.M., Woodward, J.B. % and Strother, S.C., 2004. A (sort of) new image data format standard: % Nifti-1. Neuroimage, 22, p.e1440. % % Example 1 % --------- % % This example illustrates writing a median filtered volume to a .nii % % file. % % % Load a NIfTI image using its .nii file name. % V = niftiread('brain.nii'); % % % Filter the image in 3D using a 3-by-3-by-3 median filter. % V = medfilt3(V); % % % Visualize the volume % volshow(V) % % % Write the image to a .nii file. This uses default header values. % niftiwrite(V, 'outbrain.nii'); % % Example 2 % --------- % % This example illustrates modifying the header structure and re-saving % % a .nii file. % % % Load a NIfTI image using its .nii file name. % info = niftiinfo('brain.nii'); % V = niftiread(info); % % % Edit the description of the file. % info.Description = 'Modified using MATLAB R2017b'; % % % Write the image to a .nii file. % niftiwrite(V, 'outbrain.nii', info); % % See also NIFTIINFO, NIFTIREAD. % Copyright 2016-2021 The MathWorks, Inc. matlab.images.internal.errorIfgpuArray(V, filename, varargin{:}); [V, path, filename, params] = parseInputs(V, filename, varargin{:}); if strcmp(params.Endian, 'little') machineFmt = 'ieee-le'; else machineFmt = 'ieee-be'; end headerStruct = params.Info; if params.Combined NV = images.internal.nifti.niftiImage(headerStruct); fid = fopen([filename '.nii'], 'w', machineFmt); % write header. [fid, headerBytes] = NV.writeHeader(fid, machineFmt); assert(headerBytes == 348||headerBytes == 540); % Write empty data until vox_offset skipBytes = double(headerStruct.vox_offset) - headerBytes; fwrite(fid, zeros(1,skipBytes), 'uint8'); % write image data. fid = NV.writeImage(V, fid, machineFmt); fclose(fid); if params.Compressed gzip([filename '.nii'], path); delete([filename '.nii']); end else headerStruct.vox_offset = 0; % pixels start from first byte. NV = images.internal.nifti.niftiImage(headerStruct); headerfid = fopen([filename '.hdr'], 'w', machineFmt); % write header. [headerfid, headerBytes] = NV.writeHeader(headerfid, machineFmt); assert(headerBytes == 348||headerBytes == 540); fclose(headerfid); % write image data. imagefid = fopen([filename '.img'], 'w', machineFmt); imagefid = NV.writeImage(V, imagefid, machineFmt); fclose(imagefid); if params.Compressed gzip([filename '.hdr'], path); gzip([filename '.img'], path); delete([filename '.hdr']); delete([filename '.img']); end end end %-------------------------------------------------------------------------- % Input Parsing %-------------------------------------------------------------------------- function [V, fPath, fName, params] = parseInputs(V, fName, varargin) varargin = matlab.images.internal.stringToChar(varargin); % V has to be numeric, and of specific data types. if ~isnumeric(V) error(message('images:nifti:volumeMustBeNumeric')) end % filename needs to be a string or a character vector. fName = matlab.images.internal.stringToChar(fName); if ~ischar(fName) error(message('images:nifti:filenameMustBeStringOrChar')) end [fPath, filenameOnly] = fileparts(fName); if ~isempty(fPath) fName = [fPath, filesep, filenameOnly]; else fName = filenameOnly; end % Parse the PV pairs parser = inputParser; parser.addParameter('Combined', true, @(x)canBeLogical(x)); parser.addParameter('Compressed', false, @(x)canBeLogical(x)); parser.addParameter('Endian', 'little', @(x)ischar(x)); parser.addParameter('Version', 'NIfTI1', @(x)validateVersion(x)); parser.addOptional('Info', [], @(x)validateHeader(V,x)); parser.parse(varargin{:}); params.Combined = parser.Results.Combined ~= 0; params.Compressed = parser.Results.Compressed ~= 0; params.Endian = validatestring(parser.Results.Endian, {'little', 'big'}); params.Version = validatestring(parser.Results.Version, {'NIfTI1', 'NIfTI2'}); % If Version is not specified but Info is present if any(strcmp(parser.UsingDefaults,'Version'))&&~isempty(parser.Results.Info) params.Version = parser.Results.Info.Version; end %Default value of Version for size greater than 32767 is 'NIfTI2' if any(strcmp(parser.UsingDefaults,'Version')) if any(size(V)>32767) params.Version = 'NIfTI2'; end end if strcmp(params.Version,'NIfTI1') if any(size(V)>32767) error(message('images:nifti:sizeTooBigNIfTI1')); end end if isempty(parser.Results.Info) params.Info = images.internal.nifti.niftiImage.niftiDefaultHeader(... V, params.Combined, params.Version); else params.Info = images.internal.nifti.niftiImage.toRawStruct(... parser.Results.Info, params.Combined, params.Version); end end function T = validateVersion(version) if ~ischar(version) error(message('images:nifti:invalidVersion')); else T = true; end end function TF = canBeLogical(input) if isnumeric(input) || islogical(input) TF = true; else TF = false; end end function isHeader = validateHeader(V, simpleStruct) if isstruct(simpleStruct) if ~(isequal(simpleStruct.Datatype, class(V))) error(message('images:nifti:volumeClassMustMatchHeader')) end % Allow trailing singleton dimensions in info. dimsWithSingletonExpansion = max(ndims(V), numel(simpleStruct.ImageSize)); if ~(isequal(simpleStruct.ImageSize, size(V, 1:dimsWithSingletonExpansion))) error(message('images:nifti:volumeSizeMustMatchHeader')) end if ~(length(simpleStruct.Description) <= 80) error(message('images:nifti:descriptionLessThan80')) end if isfield(simpleStruct, 'AuxiliaryFile') && ... ~(length(simpleStruct.AuxiliaryFile) <= 24) error(message('images:nifti:auxiliaryFileLessThan24')) end if isfield(simpleStruct, 'IntentDescription') && ... ~(length(simpleStruct.IntentDescription) <= 16) error(message('images:nifti:intentMustBeLessThan16')) end isHeader = true; else isHeader = false; end end