Separating yellow from red in the image

Hi,

I have an excersise in which i have to separate the red circles from the rest of the picture. I have the problem, because in the picture are also yellow circles, if I set Blue and green channel to 1, then yellow circles are also red, while if I set Green channel to 0.99 then there are still yellow circles in the picture. I want only red circles to be visible.

This is original picture:

This is code I wrote:

clc
clear all


I=imread('M.png');
I=im2double(I);
R=imhist(I(:,:,1));
G=imhist(I(:,:,2));
B=imhist(I(:,:,3));

R1=(I(:,:,1));
G1=(I(:,:,2));
B1=(I(:,:,3));


figure()
subplot(2,4,1)
imshow(I)
subplot(2,4,2)
imhist(R1);
xlabel('Próg TR=0.1')
subplot(2,4,3)
imhist(G1);
xlabel('Próg TG=0.2')
subplot(2,4,4)
imhist(B1);
xlabel('Próg TB=0.1')
subplot(2,4,5)

T1=0.95
BW = imbinarize(R1, T1);
L = bwlabel(BW);

T2=1
BW1 = imbinarize(G1, T2);
L1 = bwlabel(BW1);

T3=1
BW2 = imbinarize(B1,T3);
L2 = bwlabel(BW2);
i1(:,:,1)=L;
i1(:,:,2)=L1;
i1(:,:,3)=L2;
imshow(i1)

This is what happen if i set RGB as below:

And if i change G to 0.99

I know that yellow is [1 1 0] and I suppose, that when I change G to 1 then yellow is [1 0 0] (red). I would be very grateful for help in creating a processed image without yellow circles

Answer 1

[Image Analyst]

Why don't you use the Color Thresholder on the Apps tab and see what values it uses?