imrect

Hi. I want to be able to load a large tiff (say 1000 x 1000) and manually select a smaller ROI (e.g. 50x50) and display this new reduced image (but not by binning).

I have experimented with

    imshow('c:\funny.bmp');
    h = imrect;
    pos = h.getPosition()

but after I create the rectangle and then move it, the coordinates do not change. I am not sure how to: 1 create an "onmove" call back to ouptut the coordinates 2: Then take these and create the smaller image from the larger on (and display it) Thanks Jason

Answer 1

[Image Analyst]

Why not consider rbbox()? There is a nice example in the help for it.

Answer 2

[Sean de Wolski]

Look at the first example in the

doc imrect

documentation file. A few small changes to the callback function and you'll be all set.

[Jason]

Yes I did read this, but didn't understand the addNewPositionCallback. I assume this is the key line.

figure, imshow('cameraman.tif');

h = imrect(gca, [10 10 100 100]);

addNewPositionCallback(h,@(p) title(mat2str(p,3)));

fcn = makeConstrainToRectFcn('imrect',get(gca,'XLim'),get(gca,'YLim'));

setPositionConstraintFcn(h,fcn);

[Sean de Wolski]

addNewPositionCallback(h,@(p)assignin('base','pos',p));

This line is what to do with the new position. Here I assigned it to the base workspace as 'pos'. You could assign it somewhere else, save it, display it, etc.

[Jason]

Thanks Sean. I liked the rbbox option more as it seemed more elegant. But I do want to thank you for your help as well, I know have 2 ways.

Thankyou again.

Jason

Answer 3

[Asad Alam]

How can we identify fixed Region of interest in every image specific for pixel[120 370 ,240 340] it should be a fixed rectangular window?

[Image Analyst]

What do you mean? What's to identify? You have the coordinates of the rectangular window. What else do you need/want? What's your definition of "identify"??? I would think the coordinates you gave would identify it sufficiently enough.

[Asad Alam]

I have 10 images in a folder i have used imagedatatore to call all of them now first i have to use 1 image processed it and then loop back for the next image then processed(processing means i have to create a rectangular window on each of thr 10 images bacically each rectangular window will be the region of interest now i have to save this cropped rectangular image and then use this image for further process) it then loop back for thi i have used while loop

Basically i want tto know how can i use indexing like selecting one image crop it then do all other processing then save it and loop back

[Image Analyst]

Your "Answer" doesn't sound like an "Answer" for @Jason so I suggest you read this link

TUTORIAL: How to ask a question (on Answers) and get a fast answer

and then start your own question with your images attached. In the meantime see the FAQ:

https://matlab.fandom.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F