RandomFog

Description

Simulates fog for the image by adding random fog-like artifacts.

    This transform creates a fog effect by generating semi-transparent overlays
    that mimic the visual characteristics of fog. The fog intensity and distribution
    can be controlled to create various fog-like conditions.

    Args:
        fog_coef_range (tuple[float, float]): Range for fog intensity coefficient. Should be in [0, 1] range.
        alpha_coef (float): Transparency of the fog circles. Should be in [0, 1] range. Default: 0.08.
        p (float): Probability of applying the transform. Default: 0.5.

    Targets:
        image

    Image types:
        uint8, float32

    Number of channels:
        Any

    Note:
        - The fog effect is created by overlaying semi-transparent circles on the image.
        - Higher fog coefficient values result in denser fog effects.
        - The fog is typically denser in the center of the image and gradually decreases towards the edges.
        - This transform is useful for:
          * Simulating various weather conditions in outdoor scenes
          * Data augmentation for improving model robustness to foggy conditions
          * Creating atmospheric effects in image editing

    Mathematical Formulation:
        For each fog particle:
        1. A position (x, y) is randomly generated within the image.
        2. A circle with random radius is drawn at this position.
        3. The circle's alpha (transparency) is determined by the alpha_coef.
        4. These circles are overlaid on the original image to create the fog effect.

        The final pixel value is calculated as:
        output = (1 - alpha) * original_pixel + alpha * fog_color

        where alpha is influenced by the fog_coef and alpha_coef parameters.

    Examples:
        >>> import numpy as np
        >>> import albumentations as A
        >>> image = np.random.randint(0, 256, [100, 100, 3], dtype=np.uint8)

        # Default usage
        >>> transform = A.RandomFog(p=1.0)
        >>> foggy_image = transform(image=image)["image"]

        # Custom fog intensity range
        >>> transform = A.RandomFog(fog_coef_lower=0.3, fog_coef_upper=0.8, p=1.0)
        >>> foggy_image = transform(image=image)["image"]

        # Adjust fog transparency
        >>> transform = A.RandomFog(fog_coef_lower=0.2, fog_coef_upper=0.5, alpha_coef=0.1, p=1.0)
        >>> foggy_image = transform(image=image)["image"]

    References:
        - Fog: https://en.wikipedia.org/wiki/Fog
        - Atmospheric perspective: https://en.wikipedia.org/wiki/Aerial_perspective
    

Parameters

• alpha_coef: float (default: 0.08)
• fog_coef_range: tuple[float, float] (default: (0.3, 1))
• p: float (default: 0.5)

Targets

• Image