Transform raster image (points) to vector line

I have a raster image. In this image black points form a line.

Which matlab function help me to transform this points(raster) to line( vector)?

Unit point in line.

Thanks for answer!

[Sergey Kasyanov]

Can you describe what are you need in detail?

[Iryna Goriainova]

Yes. I have binary image (left image). I want to transform image to vector. I want to select linian object.

I used this function

I  = imread('pdfplan_trans_bw.png');

BW = edge(I(:,:,1));
[H,T,R] = hough(BW);
imshow(H,[],'XData',T,'YData',R,...
            'InitialMagnification','fit');
xlabel('\theta'), ylabel('\rho');
axis on, axis normal, hold on;
P  = houghpeaks(H,50,'threshold',1);
x = T(P(:,2)); y = R(P(:,1));
plot(x,y,'s','color','white');
% Find lines and plot them
lines = houghlines(BW,T,R,P,'FillGap',10,'MinLength',20);
figure, imshow(I), 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

As a result i get  this(rigth image):
I can not find a good paramerets to build all lines.
Maybe, can I manual add unfinished lines? Or excist enouther methods?

[Sergey Kasyanov]

You should try to rotate the image on some angle and get some frames with the Hough transform and choose the best.

Also try to run another implementations of transormation [1, 2, 3].