how can i extract only this green region ?

I want to extract those region which has the only green channels value. is it possible after converting in gray scale i can extract green channel region ? I already tried the following code but it not works.

Im = imread('1.jpg');
Im=imrotate(Im,-90);
figure,imshow(Im);
Im = imresize(Im, [512 512]);

      diff_im = Im(:,:,2);
      figure,imshow(diff_im);

Answer 1

[Image Analyst]

Try the Color Thresholder App on the Apps tab,

or see my color segmentation demos in My File Exchange,

or see the attached video that tracks green in a video.

[sufian ahmed]

but i want to extract it from rgb image

[Image Analyst]

I don't understand that statement. I gave you code to find the green pixels. What more do you want? Do you want to crop it out? If so, why? Usually that is not needed, but if you do for some reason, simply use indexing or imcrop() like I did in my Image Segmentation Tutorial. If that's not what you want, then explain exactly what "extract" means to you, because it's not obvious - it's ambiguous. Do you just want an N by 3 list of all the RGB values in the region? I have no idea.

And you say "I want to extract those region which has the only green" and also "I want to extract the red portion". So which is it? Do you understand how that could be confusing to people?

[sufian ahmed]

sorry for that. but red is just a mark. i want to extract the region inside the red mark. my input is image.

[Image Analyst]

Then the Color Thresholder app should work for you. Use it and export your code. If it still doesn't work then write back.