(image)
return image.mapim(index)
Transform image coordinates to polar.

    The image is transformed so that it is wrapped around a point in the
    centre. Vertical straight lines become circles or segments of circles,
    horizontal straight lines become radial spokes.
Transform image coordinates to polar.
Transform image coordinates to polar .
def to_polar(image):
    """Transform image coordinates to polar.

    The image is transformed so that it is wrapped around a point in the
    centre. Vertical straight lines become circles or segments of circles,
    horizontal straight lines become radial spokes.
    """
    # xy image, origin in the centre, scaled to fit image to a circle
    xy = pyvips.Image.xyz(image.width, image.height)
    xy -= [image.width / 2.0, image.height / 2.0]
    scale = min(image.width, image.height) / float(image.width)
    xy *= 2.0 / scale

    index = xy.polar()

    # scale vertical axis to 360 degrees
    index *= [1, image.height / 360.0]

    return image.mapim(index)
def to_polar ( image ) : # xy image, origin in the centre, scaled to fit image to a circle xy = pyvips . Image . xyz ( image . width , image . height ) xy -= [ image . width / 2.0 , image . height / 2.0 ] scale = min ( image . width , image . height ) / float ( image . width ) xy *= 2.0 / scale index = xy . polar ( ) # scale vertical axis to 360 degrees index *= [ 1 , image . height / 360.0 ] return image . mapim ( index )