houghpixels.m

包括进行标准Hough变换

function [r,c] = houghpixels(f,theta,rho,rbin,cbin)
%   HOUGHPIXELS Compute image pixels belonging to Hough transform bin.[R,C] =
%   HOUGHPIXELS(F,THETA,RHO,RBIN,CBIN) computes the row-column indices
%   (R,C) for nonzero pixels in image F that map to a particular Hough
%   transform bin,(RBIN,CBIN). RBIN and CBIN are scalars indicating the
%   row-column bin location in the hough transform matrix returned by
%   function HOUGH. THETA and RHO are the second and third output arguments
%   from the HOUGH function.
%寻找影响峰值的非零点

{x,y,val} =  find(f);
x=x-1;y=y-1;

theta_c =  theta(cbin)*pi/180;
rho_xy = x*cos(theta_c)+y*sin(theta_c);
nrho = length(rho);
slope = (nrho-1)/(rho(end)-rho(1));
rho_bin_index = round(slope*(rho_xy-rho(1))+1);
idx = find(rho_bin_index == rbin);
r = x(idx) + 1;c = y(idx)+1;