# Plot over an image

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turningpoint on 31 Mar 2017
Commented: turningpoint on 31 Mar 2017
Hello, I am trying to place a plot over an image and is not working.
CODE: a=[xu,xl]; %start and end x coordinates of blue line
b=[yl,yr]; %start and end y coordinates of blue line
c=[xu,xl]; %start and end x coordinates of green line
d=[yr,yl]; %start and end y coordinates of green line
imshow(img), colormap jet
hold on
plot(a,b,'blue',c,d,'green')
hold off
Does anyone has any ideia of what's wrong?
Thanks!

Joseph Cheng on 31 Mar 2017
Edited: Joseph Cheng on 31 Mar 2017
I would check your points. i see that b and d are swapped, but is there sufficient distances for you to see it with the image behind? are you sure that there isn't just a 1~2 pixel line somewhere or that start and end points are the same. you could be drawing a dot, or too small of a line to notice anything.
x = rand(500,500,3);
a=[0 500];
b = [0 500];
c = [500 0];
d = [250 0];
imshow(x),colormap jet
hold on
plot(a,b,'blue',c,d,'green')
works and draws the image and lines.
turningpoint on 31 Mar 2017
You are right! I was using the smaller version of the image(scatterbrain) Thanks a lot!