def __call__(self, image):
        """ Apply a visual effect on the image.

        Args
            image: Image to adjust
        """

        if self.contrast_factor:
            image = adjust_contrast(image, self.contrast_factor)
        if self.brightness_delta:
            image = adjust_brightness(image, self.brightness_delta)

        if self.hue_delta or self.saturation_factor:

            image = cv2.cvtColor(image, cv2.COLOR_BGR2HSV)

            if self.hue_delta:
                image = adjust_hue(image, self.hue_delta)
            if self.saturation_factor:
                image = adjust_saturation(image, self.saturation_factor)

            image = cv2.cvtColor(image, cv2.COLOR_HSV2BGR)

        return image
 Apply a visual effect on the image.

        Args
            image: Image to adjust
        
keras_retinanet/utils/image.py