How many automatic extraction of region of Interest (ROI) (ROI in image) techniques exist?

I use a manual extraction method to extract a region of interest from an image, can someone give me a new automatic technique for ROI extraction that may be i don't use it?

Answer 1

[Image Analyst]

Far and away the most common way of "automatically" identifying region(s) of interest is by thresholding. It's hard for me to think of a way that doesn't do that. Basically you start with an image, then you go through a series of image processing steps (color segmentation, texture segmentation, motion detection, morphology, cluster analysis, modeling, or whatever might be appropriate), if necessary, until you finally get to an image that can be thresholded. You then get a binary image that represents your regions of interest. If you want you can then alter the regions of interest via other methods to change their size or shape or get rid of blobs in a certain size range or whatever. Then you'll have your "final" region(s) of interest and you can get measurements from it using regionprops() or other operations.

See my Image Segmentation Tutorial for a full demo: http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862&sort=downloads_desc

[Said BOUREZG]

Thank you very much sir, i have some od fuzzy ideas about what you have said, but i want some techniques exist in literature, do you have an idea about MaxShift or or other methods like that, i have use before a manual technique to extract region of interest and it was ( http://www.mathworks.com/matlabcentral/fileexchange/31859-region-of-interest-extraction-by-free-hand-method ) very helpful to my project but an automatically method is necessary nowadays.

[Image Analyst]

You will find thousands of algorithms here: http://www.visionbib.com/bibliography/contents.html Each one was optimized for a particular application. Browse that list until you find something you like. Or else consult some books like

http://web.ipac.caltech.edu/staff/fmasci/home/astro_refs/Digital_Image_Processing_2ndEd.pdf

http://szeliski.org/Book/