returns wavelet eqivalent mask for given voxel mask
FORMAT wtobj = pr_wvmask(voxmask, params, options)
Inputs
voxmask - voxel mask image name / vol struct
params - struct with wavelet and other parameters
Fields:
scales - wavelet scales
wavelet - phiw_wavelet object
maskthresh - threshold for mask
and any other options that may be useful for the
phiw_wvimg object (see phiw_wvimg constructor)
options - any other options for creation of phiw_wvimg object
Outputs
wtobj - phiw_wvimg object with transformed mask
$Id: pr_wvmask.m,v 1.5 2005/06/18 17:53:56 matthewbrett Exp $0001 function wtobj = pr_wvmask(voxmask, params, options) 0002 % returns wavelet eqivalent mask for given voxel mask 0003 % FORMAT wtobj = pr_wvmask(voxmask, params, options) 0004 % 0005 % Inputs 0006 % voxmask - voxel mask image name / vol struct 0007 % params - struct with wavelet and other parameters 0008 % Fields: 0009 % scales - wavelet scales 0010 % wavelet - phiw_wavelet object 0011 % maskthresh - threshold for mask 0012 % and any other options that may be useful for the 0013 % phiw_wvimg object (see phiw_wvimg constructor) 0014 % options - any other options for creation of phiw_wvimg object 0015 % 0016 % Outputs 0017 % wtobj - phiw_wvimg object with transformed mask 0018 % 0019 % $Id: pr_wvmask.m,v 1.5 2005/06/18 17:53:56 matthewbrett Exp $ 0020 0021 if nargin < 1 0022 voxmask = spm_get(1,'img','Voxel mask'); 0023 end 0024 if nargin < 2 0025 params = []; 0026 end 0027 if nargin < 3 0028 options = []; 0029 end 0030 0031 params = mars_struct('ffillmerge', params, options); 0032 0033 def_struct = struct('scales',1, ... 0034 'wavelet',phiw_wavelet, ... 0035 'maskthresh', 0.05, ... 0036 'datatype','uint8'); 0037 0038 params = mars_struct('ffillmerge', def_struct, params); 0039 0040 if ischar(voxmask),voxmask=spm_vol(voxmask);end 0041 0042 % get unity wavelet 0043 wv1 = unitywavelet(params.wavelet); 0044 0045 % wt voxel mask 0046 wtobj = phiw_wvimg(voxmask, ... 0047 params, ... 0048 wv1, ... 0049 params.scales); 0050 0051 % levels, quadrants 0052 img_dims = size(wtobj.img); 0053 [tmp qs nquads] = levels(wv1, img_dims, params.scales); 0054 0055 % expand by width of wavelet for all 3 dimensions 0056 for d = 1:length(img_dims) 0057 ex(d) = width(params.wavelet, img_dims(d)); 0058 end 0059 0060 % cycle over blocks to do smoothing 0061 for l = 1:params.scales+1 0062 if l > params.scales 0063 % at top level -> only one quadrant 0064 nquads = 2; 0065 end 0066 dims = phiw_lims('dims', qs{l}{1}); 0067 for q = 1:nquads-1 0068 dblk = reshape(wtobj(l,q),dims); 0069 wtobj(l,q) = pr_expand(dblk,ex); 0070 end 0071 end 0072 0073 % rebinarize 0074 wtobj.img(wtobj.img>params.maskthresh) = 1;