function Y = selc(M1, M2, ap)%Y = selc(M1, M2, ap) coefficinet selection for highpass components %%    M1  - coefficients A%    M2  - coefficients B%    mp  - switch for selection type%          mp == 1: choose max(abs)%          mp == 2: salience / match measure with threshold == .75 (as proposed by Burt et al)%          mp == 3: choose max with consistency check (as proposed by Li et al)%          mp == 4: simple choose max%%    Y   - combined coefficients%    (Oliver Rockinger 16.08.99)% check inputs [z1 s1] = size(M1);[z2 s2] = size(M2);if (z1 ~= z2) | (s1 ~= s2)  error('Input images are not of same size');end;% switch to methodswitch(ap(1)) 	case 1,  		% choose max(abs) 		mm = (abs(M1)) > (abs(M2));  	Y  = (mm.*M1) + ((~mm).*M2);  	case 2,  	% Burts method   	um = ap(2); th = .75;  	% compute salience   	S1 = conv2(es2(M1.*M1, floor(um/2)), ones(um), 'valid');   	S2 = conv2(es2(M2.*M2, floor(um/2)), ones(um), 'valid');   	% compute match   	MA = conv2(es2(M1.*M2, floor(um/2)), ones(um), 'valid');  	MA = 2 * MA ./ (S1 + S2 + eps);  	% selection     m1 = MA > th; m2 = S1 > S2;     w1 = (0.5 - 0.5*(1-MA) / (1-th));    Y  = (~m1) .* ((m2.*M1) + ((~m2).*M2));    Y  = Y + (m1 .* ((m2.*M1.*(1-w1))+((m2).*M2.*w1) + ((~m2).*M2.*(1-w1))+((~m2).*M1.*w1)));  	  case 3,	         	% Lis method   	um = ap(2);    % first step  	A1 = ordfilt2(abs(es2(M1, floor(um/2))), um*um, ones(um));  	A2 = ordfilt2(abs(es2(M2, floor(um/2))), um*um, ones(um));    % second step  	mm = (conv2((A1 > A2), ones(um), 'valid')) > floor(um*um/2);  	Y  = (mm.*M1) + ((~mm).*M2);   case 4,   	% simple choose max   	mm = M1 > M2;  	Y  = (mm.*M1) + ((~mm).*M2);    otherwise,  	error('unkown option');end;