ChromaticAberration

Description

Add lateral chromatic aberration by distorting the red and blue channels of the input image.

    Chromatic aberration is an optical effect that occurs when a lens fails to focus all colors to the same point.
    This transform simulates this effect by applying different radial distortions to the red and blue channels
    of the image, while leaving the green channel unchanged.

    Args:
        primary_distortion_limit (tuple[float, float] | float): Range of the primary radial distortion coefficient.
            If a single float value is provided, the range
            will be (-primary_distortion_limit, primary_distortion_limit).
            This parameter controls the distortion in the center of the image:
            - Positive values result in pincushion distortion (edges bend inward)
            - Negative values result in barrel distortion (edges bend outward)
            Default: (-0.02, 0.02).

        secondary_distortion_limit (tuple[float, float] | float): Range of the secondary radial distortion coefficient.
            If a single float value is provided, the range
            will be (-secondary_distortion_limit, secondary_distortion_limit).
            This parameter controls the distortion in the corners of the image:
            - Positive values enhance pincushion distortion
            - Negative values enhance barrel distortion
            Default: (-0.05, 0.05).

        mode (Literal["green_purple", "red_blue", "random"]): Type of color fringing to apply. Options are:
            - 'green_purple': Distorts red and blue channels in opposite directions, creating green-purple fringing.
            - 'red_blue': Distorts red and blue channels in the same direction, creating red-blue fringing.
            - 'random': Randomly chooses between 'green_purple' and 'red_blue' modes for each application.
            Default: 'green_purple'.

        interpolation (InterpolationType): Flag specifying the interpolation algorithm. Should be one of:
            cv2.INTER_NEAREST, cv2.INTER_LINEAR, cv2.INTER_CUBIC, cv2.INTER_AREA, cv2.INTER_LANCZOS4.
            Default: cv2.INTER_LINEAR.

        p (float): Probability of applying the transform. Should be in the range [0, 1].
            Default: 0.5.

    Targets:
        image

    Image types:
        uint8, float32

    Number of channels:
        3

    Note:
        - This transform only affects RGB images. Grayscale images will raise an error.
        - The strength of the effect depends on both primary and secondary distortion limits.
        - Higher absolute values for distortion limits will result in more pronounced chromatic aberration.
        - The 'green_purple' mode tends to produce more noticeable effects than 'red_blue'.

    Example:
        >>> import albumentations as A
        >>> import cv2
        >>> transform = A.ChromaticAberration(
        ...     primary_distortion_limit=0.05,
        ...     secondary_distortion_limit=0.1,
        ...     mode='green_purple',
        ...     interpolation=cv2.INTER_LINEAR,
        ...     p=1.0
        ... )
        >>> transformed = transform(image=image)
        >>> aberrated_image = transformed['image']

    References:
        - https://en.wikipedia.org/wiki/Chromatic_aberration
        - https://www.researchgate.net/publication/320691320_Chromatic_Aberration_in_Digital_Images
    

Parameters

• primary_distortion_limit: int | tuple[int, int] | float | tuple[float, float] (default: (-0.02, 0.02))
• secondary_distortion_limit: int | tuple[int, int] | float | tuple[float, float] (default: (-0.05, 0.05))
• mode: Literal['green_purple', 'red_blue', 'random'] (default: 'green_purple')
• interpolation: Literal['cv2.INTER_NEAREST', 'cv2.INTER_LINEAR', 'cv2.INTER_CUBIC', 'cv2.INTER_AREA', 'cv2.INTER_LANCZOS4', 'cv2.INTER_BITS', 'cv2.INTER_NEAREST_EXACT', 'cv2.INTER_MAX'] (default: 1)
• p: float (default: 0.5)

Targets

• Image