func transverse(image *vips.Image) error { if err := image.Flip(vips.DirectionVertical); err != nil { return err } return image.Rot(vips.Angle270) }
func rot180(image *vips.Image) error { return image.Rot(vips.Angle180) }
func rot270(image *vips.Image) error { return image.Rot(vips.Angle270) }
func rot90(image *vips.Image) error { return image.Rot(vips.Angle90) }