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我想實現在MATLAB中的this paper中提出的廣義霍夫變換。我也嘗試使用this document來理解算法。我被困在計算如何計算梯度角度以找到在R表中使用的Φ。Generalized Hough R-表
我試圖運行這個matlab implementation，但輪廓函數試圖訪問負指數。缺少的功能如下。
distance.m
function [ d ] = distance(x1, y1, x2, y2)
d = sqrt((x2-x1)^2 + (y2-y1)^2);
end
barycenter.m
function [ xo, yo ] = barycenter(img)
% gravitational center coordinates of a shape
[rows, cols] = size(img);
x = ones(rows, 1)*(1:cols);
y = (1:rows)'*ones(1,cols);
area = sum(sum(img));
xo = sum(sum(double(img) .* x))/area;
yo = sum(sum(double(img) .* y))/area;
end
modelHough.m
function [H]=ModelHough(imgRGB)
% Generalized Hough Transform Modeling
% Image Binarization
imgBW = rgb2gray(imgRGB);
imgBI = imgBW < 255;
% Retrieving information about the contour: points and number (N)
N = contour(imgBI);
% Model initialization:
% row = beta value * 100
% column = number of the couple (alpha, distance)
% 3rd dimension: 1 = alpha, 2 = distance
H=zeros(round(100*2*pi),N,2);
% Compute of the barycenter coordinates
[ xo, yo ] = barycenter(imgBI);
% for each contour point
for i=1:N
% beta compute for ith contour point
b = beta(N, imgBI, i);
% research of the first column
k=1;
while H(b+1,k,2)~=0
k=k+1;
end
% compute of the alpha value
H(b+1, k, 1) = alpha(N, i, imgBI);
% compute of the distance value
H(b+1, k, 2) = distance(xo, yo, i, b);
end