Making an Image Square

This is how to easily make a square image out of a rectangular one by cropping out a square portion.  The FFT and convolution operations, for example, work better with square images, with sides equal to a powers of 2.

• Load an image.

• The image is 512 pixels high - good for FFT.
• Select / select ALL.  See yellow rectangle around image border.
• Select / force to square.  See rectangle contracted to a square, 512 pixels on a side.  The square is the right size, but not in the right position.  Click on the interior of the square and drag it to the right to the desired position.  Since the square is the full height of the image, it cannot be dragged up or down.

• Note - the bottom of the rectangle is not shown because the image above is zoomed to half size for display here.  The entire rectangle is visible when the image is actual size.

• Select / Crop image to rectangle.  This makes a new image from the square region.

  

• Discard the original image if you wish.