Detecting color and shape from an image

could any one tell me what's the wrong in this code, why it's not detecting the circle in the image accurately, also why the color is not detecting?

clc
clear all
close all
IM = imread('Circle.JPG');
IM = imresize(IM,[500,500]);
IM_BW = im2bw(IM);
IM_BW = bwareaopen(IM_BW,50);
[y,x] = find(IM_BW~=1); % Find indices and values of nonzero elements
c = mean([x y]); % Average or mean value of array
R = max(sqrt((c(1)-x).^2+(c(2)-y).^2 ));
th = linspace(0,2*pi); % Generate linearly spaced vector
xc = c(1)+R*cos(th);
xc = xc';
yc = c(2)+R*sin(th);
%%Plotting Circle
imshow(IM_BW);
hold on
plot(xc,yc,'r')
hold off
%%Detecting color
if IM(xc, yc, 1) > IM(xc, yc, 2) && IM(xc, yc, 1) > IM(xc, yc, 3)
    disp('Red!')
elseif IM(xc, yc, 2) > IM(xc, yc, 3)
    disp('Green!')
else
    disp('Blue!')
end

[Immanuel Koshy]

did u find the issue ?

Answer 1

[KSSV]

How about this approach?

IM = imread('Circle.JPG');
IM = imresize(IM,[500,500]);
IM_BW = im2bw(IM);
IM_BW = bwareaopen(IM_BW,50);
[y,x] = find(IM_BW~=1); % Find indices and values of nonzero elements
%%Get Bounding box
x0 = min(x) ; x1 = max(x) ;
y0 = min(y) ; y1 = max(y) ;
% length and breadth 
L = abs(x1-x0) ;
B = abs(y1-y0) ;
% center bounding box
C = [x0+B/2 y0+L/2] ;
%%Get distances of the points from center of bounding box
data = repmat(C,[length(x),1])-[x,y] ;
dist = sqrt(data(:,1).^2+data(:,2).^2);
%%Classify the points into circles 
nbins = 4 ;   % number of circles you want
[N,edges,bin] = histcounts(dist,nbins) ;
% plot the classified circle points for check 
figure(1)
imshow(IM)
hold on
for i = 1:nbins
    plot((x(bin==i)),y(bin==i),'.','color',rand(1,3)) ;
end

%%Circle's radii and center 
Circ = cell(nbins,1) ;
for i = 1:nbins 
    [xc1,yc1,R] = circfit(x(bin==i),y(bin==i)) ;
    Circ{i} = [xc1 yc1 R] ;
end
figure(2)
imshow(IM)
hold on
th = linspace(0,2*pi) ;
for i = 1:nbins
    xc = Circ{i}(1)+Circ{i}(3)*cos(th) ;
    yc = Circ{i}(2)+Circ{i}(3)*sin(th) ;
    plot(xc,yc,'color',rand(1,3),'linewidth',3) ;
end

[odai kiwan]

thanks man for helping but it didn't gave me what i want look at the pic