Matlab 从提取的叶脉计算角度

我试图在matlab中计算叶脉之间存在的角度。我的想法是使用Hough检测线（静脉），然后计算角度。但是当我尝试检测线条时得到的结果有点奇怪

代码如下：

[H,theta,rho] = hough(vein);
P = houghpeaks(H,4);
x = theta(P(:,2));
y = rho(P(:,1));
%lines = houghlines(BW,theta,rho,P,'FillGap',2,'MinLength',4);
lines = houghlines(BW,theta,rho,P);


figure, imshow(vein), hold on
max_len = 0;
for k = 1:length(lines)
   xy = [lines(k).point1; lines(k).point2];
   plot(xy(:,1),xy(:,2),'LineWidth',2,'Color','green');

   % Plot beginnings and ends of lines
   plot(xy(1,1),xy(1,2),'x','LineWidth',2,'Color','yellow');
   plot(xy(2,1),xy(2,2),'x','LineWidth',2,'Color','red');

   % Determine the endpoints of the longest line segment
   len = norm(lines(k).point1 - lines(k).point2);
   if ( len > max_len)
      max_len = len;
      xy_long = xy;
   end
end
% highlight the longest line segment
plot(xy_long(:,1),xy_long(:,2),'LineWidth',2,'Color','red');

---

有什么想法吗？

我想你只是把矩阵的名字混在一起了

在您的代码中，有

静脉

矩阵和

BW

矩阵。
您正在使用：

• 静脉此处：

  [H，θ，rho]=hough（静脉）

• BW此处：

  line=houghlines（BW，theta，rho，P）

我添加了行

BW=静脉，结果就不那么奇怪了：

vein = imbinarize(rgb2gray(imread('https://i.stack.imgur.com/cuwb0.jpg'))); %Read image, and convert to binary
BW = vein; %Copy vein to BW

[H,theta,rho] = hough(vein);
P = houghpeaks(H,4);
x = theta(P(:,2));
y = rho(P(:,1));
%lines = houghlines(BW,theta,rho,P,'FillGap',2,'MinLength',4);
lines = houghlines(BW,theta,rho,P);


figure, imshow(vein), hold on
max_len = 0;
for k = 1:length(lines)
   xy = [lines(k).point1; lines(k).point2];
   plot(xy(:,1),xy(:,2),'LineWidth',2,'Color','green');

   % Plot beginnings and ends of lines
   plot(xy(1,1),xy(1,2),'x','LineWidth',2,'Color','yellow');
   plot(xy(2,1),xy(2,2),'x','LineWidth',2,'Color','red');

   % Determine the endpoints of the longest line segment
   len = norm(lines(k).point1 - lines(k).point2);
   if ( len > max_len)
      max_len = len;
      xy_long = xy;
   end
end
% highlight the longest line segment
plot(xy_long(:,1),xy_long(:,2),'LineWidth',2,'Color','red');

结果:

什么是“奇怪”？Hough变换对曲线没有用处。