Normalize

Description

Applies various normalization techniques to an image. The specific normalization technique can be selected
        with the `normalization` parameter.

    Standard normalization is applied using the formula:
        `img = (img - mean * max_pixel_value) / (std * max_pixel_value)`.
        Other normalization techniques adjust the image based on global or per-channel statistics,
        or scale pixel values to a specified range.

    Args:
        mean (ColorType | None): Mean values for standard normalization.
            For "standard" normalization, the default values are ImageNet mean values: (0.485, 0.456, 0.406).
            For "inception" normalization, use mean values of (0.5, 0.5, 0.5).
        std (ColorType | None): Standard deviation values for standard normalization.
            For "standard" normalization, the default values are ImageNet standard deviation :(0.229, 0.224, 0.225).
            For "inception" normalization, use standard deviation values of (0.5, 0.5, 0.5).
        max_pixel_value (float | None): Maximum possible pixel value, used for scaling in standard normalization.
            Defaults to 255.0.
        normalization (Literal["standard", "image", "image_per_channel", "min_max", "min_max_per_channel", "inception"])
            Specifies the normalization technique to apply. Defaults to "standard".
            - "standard": Applies the formula `(img - mean * max_pixel_value) / (std * max_pixel_value)`.
                The default mean and std are based on ImageNet.
            - "image": Normalizes the whole image based on its global mean and standard deviation.
            - "image_per_channel": Normalizes the image per channel based on each channel's mean and standard deviation.
            - "min_max": Scales the image pixel values to a [0, 1] range based on the global
                minimum and maximum pixel values.
            - "min_max_per_channel": Scales each channel of the image pixel values to a [0, 1]
                range based on the per-channel minimum and maximum pixel values.

        p (float): Probability of applying the transform. Defaults to 1.0.

    Targets:
        image

    Image types:
        uint8, float32

    Note:
        - For "standard" normalization, `mean`, `std`, and `max_pixel_value` must be provided.
        - For other normalization types, these parameters are ignored.
        - For inception normalization, use mean values of (0.5, 0.5, 0.5).
        - For YOLO normalization, use mean values of (0.5, 0.5, 0.5) and std values of (0, 0, 0).
        - This transform is often used as a final step in image preprocessing pipelines to
          prepare images for neural network input.

    Example:
        >>> import numpy as np
        >>> import albumentations as A
        >>> image = np.random.randint(0, 256, (100, 100, 3), dtype=np.uint8)
        >>> # Standard ImageNet normalization
        >>> transform = A.Normalize(
        ...     mean=(0.485, 0.456, 0.406),
        ...     std=(0.229, 0.224, 0.225),
        ...     max_pixel_value=255.0,
        ...     p=1.0
        ... )
        >>> normalized_image = transform(image=image)["image"]
        >>>
        >>> # Min-max normalization
        >>> transform_minmax = A.Normalize(normalization="min_max", p=1.0)
        >>> normalized_image_minmax = transform_minmax(image=image)["image"]

    References:
        - ImageNet mean and std: https://pytorch.org/vision/stable/models.html
        - Inception preprocessing: https://keras.io/api/applications/inceptionv3/