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From: Phil Sampson on 24 Jun 2010 10:33
Hi,

I'm just getting started with Matlab and am using it to process some results for an image processing application. I want to write a script to read an image in, plot some points of interest, then save it(with the additional points included)

I've written code along the lines of

Image = imread( 'input_image.jpg' )

figure;
imshow(Image);
hold on;
plot( 100,100, 'r*');

imwrite(Image, 'outpu_image.jpg');

So, when I look at the image(prior to closing the figure window down), there is a point plotted as expected. However, when I open output_image.jpg, the plotted point hasn't been saved, only the original image.

Ideally, i'd like the saved image to include the plotted points too...is this possible?

Thanks in advance,
Phil
From: matt dash on 24 Jun 2010 11:36
"Phil Sampson" <philip_a_sampson(a)hotmail.com> wrote in message <hvvqbh$t1d$1(a)fred.mathworks.com>...
> Hi,
>
> I'm just getting started with Matlab and am using it to process some results for an image processing application. I want to write a script to read an image in, plot some points of interest, then save it(with the additional points included)
>
> I've written code along the lines of
>
> Image = imread( 'input_image.jpg' )
>
> figure;
> imshow(Image);
> hold on;
> plot( 100,100, 'r*');
>
> imwrite(Image, 'outpu_image.jpg');
>
> So, when I look at the image(prior to closing the figure window down), there is a point plotted as expected. However, when I open output_image.jpg, the plotted point hasn't been saved, only the original image.
>
> Ideally, i'd like the saved image to include the plotted points too...is this possible?
>
> Thanks in advance,
> Phil

That's because you haven't modified the matrix Image. Try using getframe after you've plotted the points to get a new image matrix.
From: Phil Sampson on 24 Jun 2010 12:18
Back of the net!!! (seems apt to use a footballing reference)

Thanks matt, it works a treat!

Phil
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