comparison util/classes/dictionaryMatrices/dctmatrix.m @ 160:e3035d45d014 danieleb

Added support classes

+function D = dctmatrix(N,K,type)
+
+error(nargchk(1,3,nargin,'struct'));
+if ~exist('type','var') || isempty(type), type='II'; end
+if ~exist('K','var') || isempty(K), K=N; end
+
+[c r] = meshgrid(0:K-1,0:N-1);
+switch type
+    case 'I'
+        D = cos(pi*c.*r/(K-1));
+        D(1,:) = D(1,:)/sqrt(2);
+        D(end,:) = D(end,:)/sqrt(2);
+    case 'II'
+        D = cos(pi*(2*c+1).*r/(2*K));
+        D(1,:) = D(1,:)/sqrt(2);
+    case 'III'
+        D = cos(pi*(2*r+1).*c/(2*K));
+        D(:,1) = D(:,1)/sqrt(2);
+    case 'IV'
+        D = cos(pi*(2*r+1+2*c+4*c.*r)/(4*K));
+    otherwise
+        error('unsupported dct type');
+end
+D = normcol(D);