util_unpack_filter.m

Standard model object recognition matlab code

function [f1, f2] = util_unpack_filter (f, which_scale)

% FUNCTION [f1, f2] = util_unpack_filter (f)
%
% Given the filter structure f, reconstruct f1 and f2 in a 4-D
% format, which is more intuitive than a sparse format, created by
% filt_package function.  Note that this function will not work for
% an extremely large filter (that's why we sparsify in the first
% place); in other words, this function is good for looking at low
% level filters.

scales = aux_get_filt_info (fieldnames(f));

if length(find(scales==which_scale)) ~= 1
  error('Scale not found');
end

scale_tag = ['s' num2str(which_scale)];

f_f1 = getfield(f, ['f1_' scale_tag]);
f_f2 = getfield(f, ['f2_' scale_tag]);
f_i1 = getfield(f, ['i1_' scale_tag]);
f_i2 = getfield(f, ['i2_' scale_tag]);
f_i3 = getfield(f, ['i3_' scale_tag]);
f_size = getfield(f, ['size_' scale_tag]);

f1 = zeros(f_size);
f2 = zeros(f_size);

for i = 1:f_size(4)
  zero_idx = find(f_i1(:,i)==0);
  for j = 1:zero_idx(1)-1
    f1(f_i1(j,i), f_i2(j,i), f_i3(j,i),i) = f_f1(j,i);
    f2(f_i1(j,i), f_i2(j,i), f_i3(j,i),i) = f_f2(j,i);
  end
end