Automatic ROI selection in image

Hi every one...

 I am doing image processing project here i need automatic roi selection like i have segmented the 
image in that i have segmented tumor i need to crop automatically. for this any ready made matlab code 
or any help is fine.

Thanks in advance...

Answer 1

[Image Analyst]

See my Image Segmentation Tutorial. It goes over all that.

http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862

[Jórdan Venâncio Leite]

Image Analyst, you again! See if you can help me with this issue:https://www.mathworks.com/matlabcentral/answers/510421-creation-of-an-automatic-polyline

It's not so difficult.Thank you!!

[Anita De Pisi]

Hi! I tried to do the same thing with my image but it doesn't work, I think because the background does not differ at all from the objects. How could I solve this? Thanks for your help.

[Image Analyst]

Anita, first of all try a noise reduction method like median filter medfilt2(), or non-local means imnlmfilt(). Then I'd get an average vertical profile and divide the image by it to compensate for vertical shading

verticalProfile = sum(grayImage, 2);
verticalProfile = verticalProfile / max(verticalProfile); % Normalize 0-1
[rows, columns, numColorChannels] = size(grayImage)
shadingImage = repmat(verticalProfile(:), 1, columns);
imshow(shadingImage, []);
flattenedImage = double(grayImage) ./ shadingImage;

Then try thresholding the flattened image. Or if that doesn't work you can play around with CLAHE : adapthisteq() to flatten the background shading.