def METHOD_NAME(image_width, image_height):
    """Generate coordinates for a tiling of unit squares."""
    # Iterate over the required rows and cells.  The for loops (x, y)
    # give the coordinates of the top left-hand corner of each square:
    #
    #      (x, y) +-----+ (x + 1, y)
    #             |     |
    #             |     |
    #             |     |
    #  (x, y + 1) +-----+ (x + 1, y + 1)
    #
    for x in range(image_width):
        for y in range(image_height):
            yield [(x, y), (x + 1, y), (x + 1, y + 1), (x, y + 1)]