makediscimage.m

beamlet变化的工具箱

function image = MakeDiscImage(n,r,x0,y0,dec)
% MakeDiscImage -- Make synthetic image of Disc
%	Usage
%		image = MakeDiscImage(n,r, x0,y0,dec)
%	Inputs
%		n		extent of delivered image, e.g. 256
%		r		radius of disc (pixels)
%		x0,y0	center of disc (assuming (0,0) at center
%		dec		generations of anti-jaggie decimation.
%				optional; default dec=2		
%	Outputs
%		image	Anti-aliased version of disc
%
%	Description
%		The Disc at (x0,y0) of radius r
%	

	if nargin < 4,
		dec = 2;
	end
	fac = 2^(dec-1);
	x   = (-fac*n):(fac*n-1);
	y   = x;
	[xx,yy] = meshgrid(x,y);
	BigImage = ((xx-(fac .* x0)).^2 + (yy-(fac .* y0)).^2) < ((fac .* r)^2);
	image = HCoarsen2d(BigImage,dec);

% Copyright (c) 1999 David L. Donoho

%	Revision History:
%		1.0	09/06/99	initial version DLD
%		1.1 09/09/99	initial version had bug; made strip, not disc!	
%
% Part of BeamLab Version:200
% Built:Friday,23-Aug-2002 00:00:00
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail [e-mail]
%
%
% Part of BeamLab Version:200
% Built:Saturday,14-Sep-2002 00:00:00
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail [e-mail]
%