Asked by FIR
on 10 Jan 2013

I have a image in which i have to draw a circle over it,i have to draw circles in many places in the image ,please tell how to procees,i saw a code in matlab central it draws only one circle ,but how to draw many circles on a image manually ,i have to click on image and have to draw circle

http://www.mathworks.com/matlabcentral/fileexchange/23121-circle-on-image

i edited from above link but the thing is that i have to draw many circle on one image ,please tell where i have to write hold on command

code

where k is my image

function [] = circle_saptha(k)

ok = 0; while ok~=1 % figure;

imshow(k);

pt = ginput(2)

x1 = pt(1,1); y1 = pt(1,2); x2 = pt(2,1); y2 = pt(2,2); xpt = [x1 x2]; ypt = [y1 y2]; %line(x,y); % Enablw this for draw rectangle on circle

r = sqrt((x2-x1)^2 + (y2-y1)^2)

pp=rsmak('circle',r,[x1 y1]); % figure; % imshow(k) fnplt(pp); line(xpt,ypt);

xtl = x1-r; xtr = x1+r; xbl = x1-r; xbr = x1+r;

ytl = y1+r; ytr = y1+r; ybl = y1-r; ybr = y1-r;

x = [xtl xtr xbr xbl xtl]; y = [ytl ytr ybr ybl ytl]; %line(x,y);

for i=1:size(k,1) for j=1:size(k,2) x2 = j; y2 = i; val = floor(sqrt((x2-x1)^2 + (y2-y1)^2)); if(val == floor(r)) nim(i,j,1) = 255; nim(i,j,2) = 0; nim(i,j,3) = 0; else nim(i,j,1) = k(i,j,1); nim(i,j,2) = k(i,j,2); nim(i,j,3) = k(i,j,3); end end end imshow(nim);

ok = (menu('Do u want to draw another circle?','No','Yes')==1) imshow(nim); end end

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Answer by Teja Muppirala
on 11 Jan 2013

Accepted answer

You keep overwriting "nim" with the same original "k". You can fix it easily:

**Step 1.** Change these lines:

ok = 0; while ok~=1 % figure; imshow(k);

to this:

ok = 0; nim = k; while ok~=1 % figure; imshow(nim);

**Step 2.** Delete these three lines:

nim(i,j,1) = k(i,j,1); nim(i,j,2) = k(i,j,2); nim(i,j,3) = k(i,j,3);

Teja Muppirala
on 11 Jan 2013

Are you sure? Run this:

k = imread('peppers.png'); ok = 0; nim = k; while ok~=1 % figure; imshow(nim); pt = ginput(2) x1 = pt(1,1); y1 = pt(1,2); x2 = pt(2,1); y2 = pt(2,2); xpt = [x1 x2]; ypt = [y1 y2]; %line(x,y); % Enablw this for draw rectangle on circle r = sqrt((x2-x1)^2 + (y2-y1)^2) %line(x,y); for i=1:size(k,1) for j=1:size(k,2) x2 = j; y2 = i; val = floor(sqrt((x2-x1)^2 + (y2-y1)^2)); if(val == floor(r)) nim(i,j,1) = 255; nim(i,j,2) = 0; nim(i,j,3) = 0; else end end end imshow(nim); ok = (menu('Do u want to draw another circle?','No','Yes')==1) imshow(nim); end

Answer by Jan Simon
on 10 Jan 2013

Edited by Jan Simon
on 10 Jan 2013

A simplified version:

while ok~=1 imshow(k); nim = <modified k> imshow(nim); ok = (menu('Do u want to draw another circle?','No','Yes') == 1); imshow(nim); end

Now `nim` is overwritten each time based on `k`. Perhaps you want:

nim = k; while ok~=1 nim = <modified nim> imshow(nim); ok = (menu('Do u want to draw another circle?','No','Yes') == 1); end

Show 1 older comment

Jan Simon
on 10 Jan 2013

"nim = nim"?! Does "codes above" mean that you insert this again:

if(val == floor(r)) nim(i,j,1) = 255; nim(i,j,2) = 0; nim(i,j,3) = 0; else nim(i,j,1) = k(i,j,1); nim(i,j,2) = k(i,j,2); nim(i,j,3) = k(i,j,3); end

Then `nim` is still filled with the values of the original `k`.

Please note, that I neither have understood, what you want to achieve, nor which problem occurs. I still do not know, what "the same problem" is. So please explain this short and clear: What happens and what do you want?

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