parse_inputs.m

介绍了傅立叶变换的基本原理

function [A,Ar,Ac,Nrho,Ntheta,Method,Center,Shape,Class] = parse_inputs(varargin) 
> Outputs: A the input image 
> Nrho the desired number of rows of transformed image 
> Ntheta the desired number of columns of transformed image 
> Method interpolation method (nearest,bilinear,bicubic) 
> Center origin of input image 
> Shape output size (full,valid) 
> Class storage class of A 

error(nargchk(3,6,nargin)); 

A = varargin{1}; 

Ar = size(A,1); > Ar = number of rows of the input image 
Ac = size(A,2); > Ac = number of columns of the input image 

Nrho = varargin{2}; 
Ntheta = varargin{3}; 
Class = class(A); 

if nargin < 4 
Method = ''; 
else 
Method = varargin{4}; 
end 
if isempty(Method) 
Method = 'nearest'; 
end 
Method = lower(Method); 
if ~any(strcmp(Method,{'nearest','bilinear','bicubic'})) 
error('Method must be one of ''nearest'', ''bilinear'', or ''bicubic''.'); 
end 

if nargin < 5 
Center = []; 
else 
Center = varargin{5}; 
end 
if isempty(Center) 
Center = [(Ac+1)/2 (Ar+1)/2]; 
end 
if length(Center(:))~=2 
error('Center should be 1x2 array.'); 
end 
if any(Center(:)>[Ac;Ar] | Center(:)<1) > THIS LINE USED TO READ 'if any(Center(:)>[Ar;Ac] | Center(:)<1)' but Ar and Ac should be swapped round -- look at line 40 for whty this should be. A.I.Wilmer, 12th Oct 2002 
num2str(['Center is ',num2str(Center(1)),',',num2str(Center(2)) ' with size of image = ',num2str(Ar),'x',num2str(Ac),' (rows,columns)']) 
warning('Center supplied is not within image boundaries.'); 
end 

if nargin < 6 
Shape = ''; 
else 
Shape = varargin{6}; 
end 
if isempty(Shape) 
Shape = 'valid'; 
end 
Shape = lower(Shape); 
if ~any(strcmp(Shape,{'full','valid'})) 
error('Shape must be one of ''full'' or ''valid''.'); 
end 

if isa(A, 'uint8'), > Convert A to Double grayscale for interpolation 
if islogical(A) 
A = double(A); 
else 
A = double(A)/255; 
end 
end