make mask-image by thresholding
Gaussian smoothing is done before thresholding
B = vb_image_to_mask(B)
B = vb_image_to_mask(B, Bval)
B = vb_image_to_mask(B, Bval, step)
B = vb_image_to_mask(B, Bval, step, Vsize)
--- input
B : mri Image data
step : subsampling step size [mm] Default: [1]
Bval : Threshold value for binary mask ,Default: [0.5]
= scalar : extract voxcel B > Bval
= [BV1 BV2] : extract voxcel BV1 < B < BV2
Vsize : voxcel size [1 x 3] ,Default: [1 1 1]
--- Optional input
plot_mode : Plot slice image.(0-2 : No, 3 : Yes)
zindx : スライス画像表示の Z-座標リスト
Nfig : number of subplot
--- output
B : masked image
MRI構造画像からマスクパターンの作成
M. Sato 2006-9-13
Copyright (C) 2011, ATR All Rights Reserved.
License : New BSD License(see VBMEG_LICENSE.txt)0001 function B = vb_image_to_mask(B, Bval, step, Vsize, plot_mode, zindx, Nfig) 0002 % make mask-image by thresholding 0003 % Gaussian smoothing is done before thresholding 0004 % B = vb_image_to_mask(B) 0005 % B = vb_image_to_mask(B, Bval) 0006 % B = vb_image_to_mask(B, Bval, step) 0007 % B = vb_image_to_mask(B, Bval, step, Vsize) 0008 % --- input 0009 % B : mri Image data 0010 % step : subsampling step size [mm] Default: [1] 0011 % Bval : Threshold value for binary mask ,Default: [0.5] 0012 % = scalar : extract voxcel B > Bval 0013 % = [BV1 BV2] : extract voxcel BV1 < B < BV2 0014 % Vsize : voxcel size [1 x 3] ,Default: [1 1 1] 0015 % --- Optional input 0016 % plot_mode : Plot slice image.(0-2 : No, 3 : Yes) 0017 % zindx : スライス画像表示の Z-座標リスト 0018 % Nfig : number of subplot 0019 % --- output 0020 % B : masked image 0021 % 0022 % MRI構造画像からマスクパターンの作成 0023 % 0024 % M. Sato 2006-9-13 0025 % 0026 % Copyright (C) 2011, ATR All Rights Reserved. 0027 % License : New BSD License(see VBMEG_LICENSE.txt) 0028 0029 if ~exist('step','var'), step = 1; end; 0030 if ~exist('Vsize','var'), Vsize = [1 1 1]; end; 0031 if ~exist('Bval','var'), Bval = 0.5; end; 0032 0033 %-------- マスクパターンの作成 -------- 0034 0035 % Size of original image data 0036 [NX,NY,NZ] = size(B); 0037 0038 % 3次元データの平滑化 0039 %tic 0040 fprintf('Gaussian smoothing\n') 0041 B = smooth3(B,'gaussian',3); 0042 %vb_ptime(toc); 0043 0044 ix = round(1:(step/Vsize(1)):NX); 0045 iy = round(1:(step/Vsize(2)):NY); 0046 iz = round(1:(step/Vsize(3)):NZ); 0047 0048 % データの間引き 0049 % subsampling 0050 B = B(ix,iy,iz); 0051 0052 % Size of subsampled image data 0053 [NBx,NBy,NBz]=size(B); 0054 0055 % Make mask image 0056 0057 Nval = length(Bval); 0058 0059 switch Nval 0060 case 1, 0061 % 閾値より大きい値を持つボクセルを抽出 0062 ix = find( B > Bval ); 0063 B = zeros(NBx,NBy,NBz); 0064 B(ix) = 1; 0065 case 2, 0066 % 2つの閾値の間にある値を持つボクセルを抽出 0067 ix = find( (Bval(1) < B) & (B < Bval(2)) ); 0068 B = zeros(NBx,NBy,NBz); 0069 B(ix) = 1; 0070 end 0071 0072 if ~exist('plot_mode','var'), return; end; 0073 0074 if plot_mode > 1, 0075 % スライス画像表示の Z-座標リスト 0076 zindx = round(zindx/step); 0077 0078 vb_plot_slice( B, [], zindx, 1, Nfig); 0079 end