How to highlight a region of Interest in an image in Matlab

I am wondering how to highlight a mask/Region of Interest (or how to mark identified objects) in an image in Matlab at given/spec开发者_开发知识库ified location?

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Another useful command is rectangle. Suppose rect holds the bounding box around the object (in format [ from_x from_y width height]), then the following code will produce a box around the object in the image:

figure('Name', 'showing detected object');
imshow( img ); % show original image
hold all;  % hold image and plot rectangle on top
rectangle( 'Position', rect );

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If you want the user to select a region on an image, then you can use the functions:

imrect
impoly
imellipse
imline

from the Image Processing toolkit.

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if you have all the vertexes of the region you are interested in you can simply use the line command. I post you how to draw a rectangle having the four vertexes (each a pair of x,y coordinates).

rect1=[a';b';c';d';a'];

line(rect1(:,1),rect1(:,2),'LineWidth',5);

I don't know if that is what you are looking for.