How to get the coordinate of cropped rectangular image?

I cropped the image as a box. Then i need to use the coordinate of the cropped image for another task. How to get that coordinate? I am using this code btw from ImageAnalyst.

point1 = get(gca,'CurrentPoint');    % button down detected
finalRect = rbbox;                   % return figure units
point2 = get(gca,'CurrentPoint');    % button up detected
point1 = point1(1,1:2);              % extract x and y
point2 = point2(1,1:2);
p1 = min(point1,point2);             % calculate locations
offset = abs(point1-point2);         % and dimensions

% Find the coordinates of the box.
xCoords = [p1(1) p1(1)+offset(1) p1(1)+offset(1) p1(1) p1(1)];
yCoords = [p1(2) p1(2) p1(2)+offset(2) p1(2)+offset(2) p1(2)];
x1 = round(xCoords(1));
x2 = round(xCoords(2));
y1 = round(yCoords(5));
y2 = round(yCoords(3));
hold on
axis manual
plot(xCoords, yCoords, 'b-'); % redraw in dataspace units

[Aminah Zhulaika]

@Image Analyst please help me.

Answer 1

[Image Analyst]

The coordinates are x1,x2,y1, and y2. So to crop:

croppedImage = originalImage(y1:y2, x1:x2, :);

[Aminah Zhulaika]

Got it. But how to code if I want to use same coordinate to crop other image. This is what i did and turns out the cropped area is not the same as I cropped earlier. I appreaciate your reply a lot @Image Analyst.

rect=[x1 x2 y1 y2];
J=imcrop (I,rect);

[Walter Roberson]

That sounds like you are asking for a way to find a "similar" area in a second image, I2, that matches the characteristics of what you stored in J. For example, if you had manually cropped down to a refrigerator in one image, it sounds as if you would want to use the refrigerator as a guide to finding a refrigerator in another image. Is that correct?

[Aminah Zhulaika]

Yes, exactly @Walter Roberson. I have manually cropped the area in image 1. and then I want to use the coordinate of the cropped image 1 to be used for automatically cropped for image 2. Do you know how?

[Image Analyst]

imcrop() uses [xLeft, yTop, xWidth, yHeight] format, NOT (y1, y2, x1, x2) like you'd do if you were indexing. so

r = [x1, y1, (x2-x1), (y2-y1)];
croppedImage = imcrop(rgbImage, r);

[Aminah Zhulaika]

Thank you very much! Now I get the answer and result already. Appreciate your help very much.

Answer 2

[Walter Roberson]

I have manually cropped the area in image 1

Then I predict that the issue is that you do not know what coordinates you manually outlined. The way to deal with that is to ask for an additional output from imcrop()

[J1, rect] = imcrop(I1);
J2 = imcrop(I2, rect);