getwin

 GETWIN chooses an appropriate window size for the chessboard corner filter
 
 GETWIN chooses the window size depending on the spread of the points. It
 simply chooses a window size which does not include any other points.
 
 USAGE:
     win=getwin(img,pt,crnrpts)
 
 INPUTS:
     img: grayscale image (only used for size)
 
     pt: coordinates of pixel of interest
 
     crnrpts: 2xN array of all other points
 
 OUTPUTS:
     win: window size

0001 function win=getwin(img,pt,crnrpts)
0002 % GETWIN chooses an appropriate window size for the chessboard corner filter
0003 %
0004 % GETWIN chooses the window size depending on the spread of the points. It
0005 % simply chooses a window size which does not include any other points.
0006 %
0007 % USAGE:
0008 %     win=getwin(img,pt,crnrpts)
0009 %
0010 % INPUTS:
0011 %     img: grayscale image (only used for size)
0012 %
0013 %     pt: coordinates of pixel of interest
0014 %
0015 %     crnrpts: 2xN array of all other points
0016 %
0017 % OUTPUTS:
0018 %     win: window size
0019 
0020 
0021 x=pt(1);
0022 y=pt(2);
0023 nearestpt=findnearest([x;y],crnrpts,1);
0024 win=max(abs(nearestpt-[x;y]))-2;
0025 
0026 % check for borders
0027 if x-win<1
0028     win=x-1;
0029 end
0030 if x+win>size(img,1)
0031     win=size(img,1)-x;
0032 end
0033 if y-win<1
0034     win=y-1;
0035 end
0036 if y+win>size(img,2)
0037     win=size(img,2)-y;
0038 end