How to extract an image?

The black region is the road and white region is the surrounding. I need to extract the black region alone and display the road. Can anybody help me with the matlab code?

[Edit by Image Analyst -- images inserted]

Answer 1

[Image Analyst]

We can't see your .fig files. Attach PNG format images with the green and brown frame icon. Until then, see my Image Segmentation tutorial or color segmentation tutorials: http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862

Or else see the Color Thresholder on the Apps tab of the tool ribbon.

[Darsana P M]

i have made the image in png format

[Image Analyst]

I did what I was hoping you'd do up top on your original post.

You can find lane marker finding and road following papers here: http://www.visionbib.com/bibliography/contentsactive.html#Active%20Vision,%20Camera%20Calibration,%20Mobile%20Robots,%20Navigation,%20Road%20Following

15.3.3 Road, Path Following Operators
  15.3.3.1 Road Following, Depth, Stereo Based, Off-Road, Safe Path
  15.3.3.2 Ground Plane Detection
  15.3.3.3 Lane Detection, Lane Following, White Line Detection
  15.3.3.4 Indoor Navigation Issues, Lines, Walls, Doors, Flat Surfaces
  15.3.3.5 CMU Road Followers, ALVINN YARF MANIAC
  15.3.3.6 Obstacle Dectection, Other Vehicles, Objects on the Road
      15.3.3.6.1 Collision Avoidance, Collision Detection, Vehicles, Objects on the Road
      15.3.3.6.2 Obstacles, Objects on the Road Using Radar, Sonar, Active Vision 
  15.3.3.7 Airplane Obstacles, Collision Detection, Sense and Avoid, Aircraft Landings
  15.3.3.8 Road Signs, Traffic Signs, Traffic Lights, Objects along the Road, Inspections

To mask your image so that the road shows up in full RGB and elsewhere is blackened, starting with your binaryImage, you can do it like this:

mask = ~binaryImage; % Invert it so the road is white
% Mask the image using bsxfun() function
maskedRgbImage = bsxfun(@times, rgbImage, cast(mask, 'like', rgbImage));