Detecting lanes in a video using matlab and image processing. - matlab

Question

I am a little bit new to matlab and imageprocessing and I was given a task at my faculty to carry out a project which detects the lanes for a moving car in a video. I tried to use some tutorials on Mathworks and other sites and there were really helpful and I came out with a code that detects lanes in an image and I just want to know how to apply my code on a video as I see it working properly on an image.
and here is my code :
img = imread ('test_image.jpg');
I = rgb2gray (img);
%making a gaussian kernel
sigma = 1 ; %standard deviation of distribution
kernel = zeros (5,5); %for a 5x5 kernel
W = 0 ;
for i = 1:5
for j = 1:5
sq_dist = (i-3)^2 + (j-3)^2 ;
kernel (i,j) = exp (-1*exp(sq_dist)/(2*sigma));
W = W + kernel (i,j) ;
end
end
kernenl = kernel/W ;
%Now we apply the filter to the image
[m,n] = size (I) ;
output = zeros (m,n);
Im = padarray (I , [2 2]);
for i=1:m
for j=1:n
temp = Im (i:i+4 , j:j+4);
temp = double(temp);
conv = temp.*kernel;
output(i,j) = sum(conv(:));
end
end
output = uint8(output);
%--------------Binary image-------------
level = graythresh(output);
c= im2bw (output,level);
%---------------------------------------
output2 = edge (c , 'canny',level);
figure (1);
%Segment out the region of interest
ROI = maskedImage;
CannyROI = edge (ROI , 'canny',.45);
%----------------------------------
set (gcf, 'Position', get (0,'Screensize'));
%subplot (141), imshow (I), title ('original image');
%subplot (142), imshow (c), title ('Binary image');
%subplot (143), imshow (output2), title ('Canny image');
%subplot (144), imshow (CannyROI), title ('ROI image');
[H ,T ,R] = hough(CannyROI);
imshow (H,[],'XData',T,'YData',R,'initialMagnification','fit');
xlabel('\theta'), ylabel('\rho');
axis on , axis normal, hold on ;
P = houghpeaks(H,5,'threshold',ceil (0.3*max(H(:))));
x = T(P(:,2));
y = R(P(:,1));
plot (x,y,'s','color','white');
%Find lines and plot them
lines = houghlines (CannyROI,T,R,P,'FillGap',5,'MinLength',7);
figure, imshow (img), hold on
max_len = 0 ;
for k = 1:length(lines);
xy = [lines(k).point1; lines(k).point2];
plot (xy(:,1), xy(:,2), 'LineWidth', 5 , 'Color', 'blue');
%plot beginnings and ends of the 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
and here is the link of the image and the video :
https://github.com/rslim087a/road-video
https://github.com/rslim087a/road-image
Thanks in advance.

Answer 1

Basically video processing happens in such a way that video will be converted to video frames (images). So if you need, you can convert your video to video frames and run the code, looping over the folder having the video frames. Change the imread function to get images from video frames folder...
img = imread(path_to_video_frames_folder/*)