MATLAB Central Newsreader - display centre of an image

display centre of an image

ramya — Sun, 03 Feb 2008 08:44:01 -0500

can someone tell me how to display the centre of an
image.. plzzzz...i need to display the image with a red
mark in the centre.. how do i do that???

Re: display centre of an image

roberson@ibd.nrc-cnrc.gc.ca (Walter Roberson) — Sun, 03 Feb 2008 11:59:01 -0500

In article <fo3ush$qg$1@fred.mathworks.com>,
ramya <tulips2000@gmail.com> wrote:
>can someone tell me how to display the centre of an
>image.. plzzzz...i need to display the image with a red
>mark in the centre.. how do i do that???

get() the Parent of the image. It will be an axis.
get() the XLim of the axis. This will be a vector of length 2.
get() the YLim of the axis. This will be a vector of length 2.
Average the two elements of the XLim.
Average the two elements of the YLim.
The two averages are the X and Y coordinates of the centre.
plot() at that location with an appropriate color and marker
specification.
--
"History is a pile of debris" -- Laurie Anderson

Re: display centre of an image

Vihang Patil — Sun, 03 Feb 2008 13:16:02 -0500

"ramya " <tulips2000@gmail.com> wrote in message
<fo3ush$qg$1@fred.mathworks.com>...
> can someone tell me how to display the centre of an
> image.. plzzzz...i need to display the image with a red
> mark in the centre.. how do i do that???

load clown
imshow(X,map);
hold on;
plot(size(X,2)/2,size(X,1)/2,'ro','LineWidth',2);
%doc plot

HTH
Vihang