background removal

i have a pavement image with a crack. i would like to remove the background of that image.so that i can get a clear picture of the crack.I don't have the image of the pavement without crack.So,i cant use the subtract method to remove the background.Is there any other way to remove the background.can any one help me out.

[Ashish Uthama]

Siddharth, posting a sample image would help you get a better answer.

Answer 1

[Image Analyst]

You could just blur the heck out of it with conv2(). Or else use the image to model a perfectly smooth function, like a quadratic or something. I used polyfitn for this but John removed it from the File Exchange. Maybe you could try this instead: http://www.mathworks.com/matlabcentral/fileexchange/13719-2d-weighted-polynomial-fitting-and-evaluation

[siddharth s]

can u send me the code how to perform that operation,with a sample image??sorry for the trouble.

[Walter Roberson]

How about instead of _us_ sending you code, _you_ make your image available together with what you have attempted so far?

[siddharth s]

i separated image and the background using filtering technique.. thanks again 4 ur help

[Image Analyst]

Good. We're glad you solved it.

[Karan]

Could you share what exactly you did because I have exactly the same problem. Thanks

[Image Analyst]

Where did you post your image? I think you should start your own thread on your own question and image.

Answer 2

[Ashish Uthama]

You might also consider extracting the crack instead of removing the background :) What do you intend to do after you 'remove the background' ?

You might be able to use functions like edge to detect and process the edge.

[siddharth s]

i tried extracting the crack using edge detection method but it displays all edges which are not a part of the crack. can u suggest something for extracting the crack alone

[Walter Roberson]

We need a sample image.

http://www.mathworks.com/matlabcentral/answers/7924-where-can-i-upload-images-and-files-for-use-on-matlab-answers