How to find the dimensions of a specific area in an existing image?

Say I'm given an image with a rectangular space made entirely of green pixels. I want to find the dimension of that area that is made entirely of green pixels.

This is what I have so far:

numGreenPixels=img(:,:,1)==0 & img(:,:,2)==255 & img(:,:,3)==0
numGreenPixels = sum(numGreenPixels(:));

this would only given me the total number of green pixels, when I need to find the dimension of said space. How do I go about this?

[KSSV]

when I need to find the dimension of said space.

YOu can find the dimensions if you can arrange the data into a matrix form......is your green region a square/ rectangle? If it is taking some other irregular shape, how you will specify the dimensions?

[Alexander West]

It is always a rectangle/square, sorry if I didn’t specify.

Answer 1

[KSSV]

In that case......the length of unique of x,y should give you the dimensions. You have numGreenPixels as a matrix of 0 and 1's.

[y,x] = find(numGreenPixels) ; 

If it is not clear attach your image.

[Alexander West]

function refrigerator(fridge,picNeed)

img=imread(picNeed)

background=imread(fridge);

r=(img(:,:,1))

g=(img(:,:,2))

b=(img(:,:,3))

numGreenPixels=img(:,:,1)==0 & img(:,:,2)==255 & img(:,:,3)==0

[y,x] = find(numGreenPixels) ;

background=imresize(background,[x,y])

[w,r] = strtok(fridge,'.')

newFile= ['decorated_' w r]

imwrite(img,newFile)

end

Doing this returns an error with the resize function? Logically, it should work right?