region of interest of certain objects

hi, my idea here is to draw a region of interest on a marker. the marker is square in shape printed on a piece of paper. I want to draw a region of interest around the marker and crop it out so that i can process it further. i want to detect and hopefully track the marker in the image.

i hope i made my idea clear. it there is any uncertainties let me know and ill clarify.

Answer 1

[Image Analyst]

You idea is clear enough, I guess. But do you have a question, or are you just notifying us of your project? Well, good luck with it. If you do come up with any questions, post them along with the URL of your image (where you uploaded it to) and your attempt at coding up your idea.

[Image Analyst]

1. Threshold the image.
2. Call regionprops to find the areas and bounding boxes of all the bright objects.
3. Take the largest object only and get its bounding box then call imcrop().

See my image segmentation tutorial in my File Exchange to see how to extract objects.

[messaoudi nada]

@Image Analyst i want to create ROI in img without cropped it ,i just want to extract the features from the ROI in face , can u help me please anD tell me how can i do it? , thanks in advance sir !

[Image Analyst]

@messaoudi nada just get the binary image of the face somehow, like with freehanddraw() or thresholding or some other way. Then just call regionprops with the image and the mask. Ask in a new question with your image attached if you need more help. See my Image Segmentation Tutorial for a full demo:

Image Analyst's File Exchange

[messaoudi nada]

@Image Analyst thanks for your help sir , i tried this code and i got the binary image and the binarymask but i don't know how can i find the masked roi ! for features detection , andi called regionprops but i don't know how i use it to get roi in my images

ch=strcat('C:\Users\nada\Desktop\nadamastere\bd\fatigue\p1\image_',num2str(v,'%d'),'.png');

I1=imread(ch);

I1=imresize(I1,[row,colum]);

I1=rgb2gray(I1);

I1=im2double(I1);

I1=im2bw(I1);

figure(2);imshow(I1);

roI=imrect(gca,[20 20 110 120]);

bw=createMask(roI);

figure(3);imshow(bw);

props = regionprops(bw,'BoundingBox');

b =props(1).BoundingBox;

[Image Analyst]

@messaoudi nada, like I said "Ask in a new question with your image attached if you need more help.". I clicked on your name but did not see the new question in a new thread. Did you do this yet? Let's not hijack @genesis's 8 year old thread here.

[messaoudi nada]

@Image Analyst you'r right sir ,sorry ! , i asked new question in a new thread right now ,i hope you can help me

Answer 2

[genesis]

i was trying to get some suggestions on how i am able to do that. the marker is was saying look like http://s1278.photobucket.com/user/bhan_92/media/corr2_2_crop_zps1d903ad0.jpg.html

[Narges M]

you could also use Hough Transform and your marker's dimensions to in order to find it on a larger image.