How we can detect road from satellite images using DOG filter?

following code can't detect road accurately.so pls help..

fontSize = 10;
I = imread('ds5.jpg');
grayImage = rgb2gray(I);
% Get the dimensions of the image.  
% numberOfColorBands should be = 1.
[rows columns numberOfColorBands] = size(grayImage);
% Display the original gray scale image.
subplot(2,2,1);
imshow(I);
title('Original Image', 'FontSize', fontSize);
subplot(2,2,2);
imshow(grayImage);
title('grayscale Image', 'FontSize', fontSize);
gaussian1 = fspecial('Gaussian', 21, 15);
gaussian2 = fspecial('Gaussian', 21, 20);
dog = gaussian1 - gaussian2;
dogFilterImage = conv2(double(grayImage), dog, 'same');
subplot(2,2,3);
imshow(dogFilterImage, []);
title('DOG Filtered Image', 'FontSize', fontSize);
bw =(dogFilterImage);
subplot(2,2,4);
imshow(bw);

[shantanu shukla]

hay neetha if u got the answer then pls suggest me for it, i m also doing my project to extract the road from satellite images

[Image Analyst]

The people in my link have the answers. Are their answers okay?

[Sachin Fernandes]

Did you manage to get this working?

Answer 1

[Image Analyst]

Either adjust your parameters, or use multiple spectral bands, or pick a successful algorithm published here:

http://iris.usc.edu/Vision-Notes/bibliography/contentscartog.html#Cartography,%20Aerial%20Images,%20Remote%20Sensing,%20Buildings,%20Roads,%20Terrain,%20ATR

22.2 Road Network Detection, Road Extraction Systems
    22.2.1 Road Following, Road Tracking Systems, Connecting Fragments, Extracting Fragments
    22.2.2 Road Network Model Integration, Updating, and Change Detection
    22.2.3 Road Extraction in Radar, SAR, Lidar, Laser, Depth

[Tousif Zaman]

Would you please help me to get an algorithm from here? I can only see the names of some papers here but no access to the algorithm or code.

[Image Analyst]

I don't have them either. You have to buy them from the publisher. If you can't figure out how to do that, try ScienceDirect.com or similar sites. If you still can't figure out how to get the paper, then look at the author's web site. Sometimes they post it there. At least you could ask them. Anyway, I don't have them.