Hello

I am trying to embed imagej in a java application, as I need to do the following sequence of operations on a passed image:
1-make rectangle around certain area.
2-Crop

The problem is the step of making rectangle does not work.

Here is a piece of code:

implus.setImage(bf); //bf is a buffered image
ij.run(implus, "Make Binary", ""); // converting to binary
ij.makeRectangle(30, 30, 30, 30);
implus.show();

The output of the program:
There are no images open.

and then the application stops.

Can any one tell me how I can do the operation of making rectangular selection on a passed image or buffered image?

Thanks