add mosaic.m

src/mosaic.m

@@ -0,0 +1,50 @@
+function M = mosaic (stack, refImg)
+%%MOSAIC Create a 2-D mosaic of images from a 3-D stack.
+%
+%  M=MOSAIC(STACK) takes a 3-D STACK of images and attempts to stitch them
+%  together in a 2-D image with dimensions as close to square as possible.
+%
+%  Written by David S. Smith, 3 Apr 2011.
+%
+%  History
+%    v1.0 - Initial revision.
+
+[n1 n2 n3] = size(stack);
+
+if n3 == 1
+  M = stack;
+  return;
+end
+
+if nargin == 2 
+  for k = 1:n3
+    stack(:,:,k) = stack(:,:,k) - refImg;
+  end
+end
+
+if n3 == 1, error('MOSAIC> Input must be 3D.'); end
+
+n = round(sqrt(n3)); % starting point: integer nearest to the square root
+
+% find largest integer less than or equal to sqrt that evenly divides the
+% number of images in the stack
+for k = n:-1:1
+	if ~mod(n3,k), break; end
+end
+
+% figure out the best dimensions
+j = n3 / k;
+ny = min(j,k);
+nx = max(j,k);
+
+% stick them together
+if isa(stack,'logical')
+  M = false(ny*n1,nx*n2);
+else
+	M = zeros(ny*n1,nx*n2,class(stack));
+end
+for k = 1:ny
+	for j = 1:nx
+    M(1+n1*(k-1):n1*k,1+n2*(j-1):n2*j) = stack(:,:,j+(k-1)*nx);
+	end
+end