Saving Figure Data into a Matrix

Hello.

I'm using 'image()' to display an image. I'm adding some annotations using text.

I'd like to save the final result as matrix (3 Channels of the displayed image width and height). Something like using: OI = get(imageHandler, 'CData'); Yet which includes all the annotations I added.

I know I can use 'saveas' and 'print' yet then the data undergoes some interpolation while I want the data as it is back as a matrix.

Anyone knows how to do it?

Thanks.

[Zhiyu Xiao]

Great question!

Answer 1

[Gerd]

Hi Royi,

you can use the getframe command.

logo = imread('Logo.jpg','jpg');
image(logo);
text(20,30,'Hello')
f=getframe(gcf)
new=f.cdata
imwrite(new,'new.jpg','JPEG')

Gerd

[Royi Avital]

Hello Gerd.

Well, it's almost perfect.

Let's say I is a 250 by 250 pixels image.

I use 'image' to display it.

I add annotations on the image itself.

Using 'getframe' I get a matrix which is much bigger than 250 x 250.

I want to get back not the whole figure (As in 'saveas') but only the image itself with all the annotations.

Thanks.

[Yue]

I met the same question.Have you solved this problem? Looking forward to your answer.

[Yue]

I solved this problem just now.

You can try gca command.It returns the current figure or image.

Example:

Frame = getframe(gca);
FrameData = Frame.cdata;
imshow(FrameData)
imwrite(FrameData,'teat.png','PNG');

Answer 2

[Leslie Solorzano]

https://se.mathworks.com/help/matlab/ref/frame2im.html