Consider an imaging system with 128×128 pixels that produces a noiseless, distortion-free digital image. It is used to digitize checkerboard patterns where all squares of the pattern are in the field of view. Using this imaging system, if a checkerboard pattern with 128×128 squares is digitized, each square will be 1×1 pixel in size. What is the size of the checkerboard square in the generated digital image for which spatial aliasing is observed (measured in pixels of the imaging system)?