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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def to_rectangular(image):
 """Transform image coordinates to rectangular. The image is transformed so that it is unwrapped from a point in the centre. Circles or segments of circles become vertical straight lines, radial lines become horizontal lines. """

    # xy image, vertical scaled to 360 degrees
    xy = pyvips.Image.xyz(image.width, image.height)
    xy *= [1, 360.0 / image.height]

    index = xy.rect()

    # scale to image rect
    scale = min(image.width, image.height) / float(image.width)
    index *= scale / 2.0
    index += [image.width / 2.0, image.height / 2.0]

    return image.mapim(index)