divine_feature_extract.m

function f = divine_feature_extract(im)

% Function to extract features given an image
%% Constants
num_or = 6;
num_scales = 2;
gam = 0.2:0.001:10;
r_gam = gamma(1./gam).*gamma(3./gam)./(gamma(2./gam)).^2;

%% Wavelet Transform +  Div. Norm.

if(size(im,3)~=1)
    im = (double(rgb2gray(im)));
end
[pyr pind] = buildSFpyr(im,num_scales,num_or-1);

[subband size_band] = norm_sender_normalized(pyr,pind,num_scales,num_or,1,1,3,3,50);



f = [];

%% Marginal Statistics


h_horz_curr = [];
for ii = 1:length(subband)
    t = subband{ii}; 
    mu_horz = mean(t);
    sigma_sq_horz(ii) = mean((t-mu_horz).^2);
    E_horz = mean(abs(t-mu_horz));
    rho_horz = sigma_sq_horz(ii)/E_horz^2;
    [min_difference, array_position] = min(abs(rho_horz - r_gam));
    gam_horz(ii) = gam(array_position);    
end
f = [f sigma_sq_horz gam_horz]; % ind. subband stats f1-f24

%% Joint Statistics


clear sigma_sq_horz gam_horz
for ii = 1:length(subband)/2
    t = [subband{ii}; subband{ii+num_or}];
    mu_horz = mean(t);
    sigma_sq_horz(ii) = mean((t-mu_horz).^2);
    E_horz = mean(abs(t-mu_horz));
    rho_horz = sigma_sq_horz(ii)/E_horz^2;
    [min_difference, array_position] = min(abs(rho_horz - r_gam));
    gam_horz(ii) = gam(array_position);
end
f = [f gam_horz];
t = cell2mat(subband');
mu = mean(t);
sigma_sq = mean((t-mu_horz).^2);
E_horz = mean(abs(t-mu_horz));
rho_horz = sigma_sq/E_horz^2;
[min_difference, array_position] = min(abs(rho_horz - r_gam));
gam_horz = gam(array_position);

f = [f gam_horz];

%% Hp-BP correlations


hp_band = pyrband(pyr,pind,1);
for ii = 1:length(subband)
    curr_band = pyrband(pyr,pind,ii+1);
    [ssim_val(ii), ssim_map, cs_val(ii)] = ssim_index_new(imresize(curr_band,size(hp_band)),hp_band);
end
f = [f cs_val];


%% Spatial Correlation

b = [];
for i = 1:length(subband)/2
    b = [b find_spatial_hist_fast(reshape(subband{i},(size_band(i,:))))];
end
f = [f b];

%%  Orientation feature...

l = 1; clear ssim_val cs_val
for i = 1:length(subband)/2
    for j = i+1:length(subband)/2
      [ssim_val(l), ssim_map, cs_val(l)] = ssim_index_new(reshape(subband{i},size_band(i,:)),reshape(subband{j},size_band(j,:)));  
      l = l + 1;
    end
end
f = [f cs_val];