how to separate the tumor portion from the image?

I am detecting brain tumor b using median filter watershed segmentation. I converted the image to grey,remove the noise using median filter, adjusted the image,converted it to lack and white and then took the compliment. Then i applied the distance transform and use watershed segmentation. I want to know how to extract the tumor infected area from the image?? And also want to know how to calculate the area of the infected area.? Please tell me...

[Jhilam Mukherjee]

if your image is a binary image apply regionprops

[jasleen sha]

yes i am applying regionprops command but its not working for me... May be I'm applying in wrong way...

Answer 1

[Image Analyst]

You said you "converted it to lack and white" so you've already segmented the tumor into a binary image, so now we just need to know what you mean by "extract the tumor". Do you mean like crop out, or mask the exterior area to black???

To compute area, just use regionprops on the binary image. See my Image Segmentation Tutorial for an example. http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862

I'm not sure why you did a distance transform and then watershed on that. What was the point in doing that? I mean, you already have the segmented, binary image so what are all these subsequent operations for?

[jasleen sha]

I applied watershed method so as to separate the two touching objects. I converted the image into binary image. After conversion, I just want to crop out the tumor infected area which is white by using any method but its not working out as em applying regionprops command.. will you tell me the method to separate white part from the black one?

[Image Analyst]

regionprops gives the bounding box of the blob, if you ask it to. Then you can just crop it out using imcrop() and that bounding box. See my Image Segmentation Tutorial for a full demo. http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862

[Shyme Bhate]

Hi, Image Analyst. I need little guidance, As I want to extract tumorius part from the brain MRI , I am extracting that part by split the images but how to know the exact coordinates of the image ?

[Image Analyst]

You can ask regionprops() for PixelList and it will give you the coordinates of every pixel in the blob you're interested in. Start a new question if you still have trouble. Also, see attached demo.