How can i detect the green region(meter display) & crop it out using matlab?

I want to extract the green region(meter display).Here i attached a image which is digital electric meter. I want to extract only this region which contains meter reading value.if i only detect green region then other green region also detected.But i want to detect only the green region which contains meter reading.How can i do that in matlab ? sorry for asking question again. i cant explain it properly in my previous ques.

       close all;
    clear all;
    clc;
    Im = imread('2.jpg');
    Im = imresize(Im, [512 512]);
    diff_im = imsubtract(Im(:,:,2),rgb2gray(Im));
    figure,imshow(diff_im);

Answer 1

[Image Analyst]

OK, it was so trivial and quick that I did it for you. See attached m-file, which produces this:

You can use imfill() if you want the black pixels inside.

[sufian ahmed]

Thanks sir. Sir i have some question. 1) why u do rgb2lab ? 2)how can u determine the threshold for 3 channel ? 3) 'maskedRGBImage(repmat(~BW,[1 1 3])) = 0' ... why u do this ? and it is really great for me if u give a overview of this code... bth, really thanks

[Image Analyst]

Use the Color Thresholder and look at the color cloud. Which colorspace do you thing would be easier to carve out a box in? Not RGB. You could probably also do it in HSV, but LAB looked like the green pixels were the most distinct/separated.

[Shehzad Ali]

Sir I also use ur above code for same purpose but I can't handle color scheme in my dataset becuse in my dataset led colour is different. plz help me regarding this issue as soon as possible. thnx

my dataset sample is here.

[Image Analyst]

There are so many variables that we don't know about. Like the color - will it be the same for all images in your collection? And do they all have a dark rectangle that we can find to erase everything outside it? How bad could the reflections be? Could the display be rotated even more than that? Do all images have the same clutter outside the yellowish-green display? Or do the digits, letters, and graphics vary? Is the display always roughly in the center, or could it be anywhere? Are they all stamped with the blue graphics? You need to know all those things because they could make what is a very simple application (like cropping to known coordinates and doing ocr) to something much more complicated.

Answer 2

[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.