Detection Of water bodies from rest of the image

I want to extract only water bodies from rest of the image..how can i do this efficiently? Can anyone help me?

[Image Analyst]

Where did you upload your image to?

[Gaurav]

Sir i want to extract only the water part as shown in the following image..

http://www.freemalaysiatoday.com/wp-content/uploads/2011/01/No-water-electricity-roads-in-Jabus-constituency-1.jpg

Please help me to achieve this efficiently...

Answer 1

[Sean de Wolski]

I = your_image;
for ii = size(I,1):-1:1
  for jj = size(I,2):-1:1);
     water(ii,jj) = isWet(I(ii,jj,:))
  end
end

Now you just need to write isWet().

[Gaurav]

Thanks for your reply...

But I am confused about what to write in isWet.Is this a threshold function for pixel values corresponding to water color? or anything else?

Please help me as i m very new to image processing and matlab...

Thank u.

Answer 2

[Gaurav]

Thanks for your reply... But I am confused about what to write in isWet.Is this a threshold function for pixel values corresponding to water color? or anything else? Please help me as i m very new to image processing and matlab... Thank u.

[Image Analyst]

It looks like Sean's joke went over your head. But you still have a chance to respond to my comment about posting your image.

[Gaurav]

Sir i want to extract only the water part as shown in the following image..

http://www.freemalaysiatoday.com/wp-content/uploads/2011/01/No-water-electricity-roads-in-Jabus-constituency-1.jpg

Please help me to achieve this efficiently...