o
    :Î®c
  ã                   @   sP   d dl mZmZ d dlmZ d dlmZ d dlmZ d dl	Z
di i fdd„ZdS )é    )Úsanity_check_imageÚtrimap_split)Úcf_laplacian)Úichol)ÚcgNc                 C   sÚ   |du rt }t| ƒ |jdd… \}}t|ƒ\}}}	}
t| fi |¤d|	i¤Ž}||
dd…f dd…|
f }||
dd…f dd…|	f }||	 }| ¡  ¡ }t|| |¡ fd||ƒi|¤Ž||
< t	 
|dd¡ |j¡}|S )a)  
    Estimate alpha from an input image and an input trimap using Closed-Form Alpha Matting as proposed by :cite:`levin2007closed`.

    Parameters
    ----------
    image: numpy.ndarray
        Image with shape :math:`h \times  w \times d` for which the alpha matte should be estimated
    trimap: numpy.ndarray
        Trimap with shape :math:`h \times  w` of the image
    preconditioner: function or scipy.sparse.linalg.LinearOperator
        Function or sparse matrix that applies the preconditioner to a vector (default: ichol)
    laplacian_kwargs: dictionary
        Arguments passed to the :code:`cf_laplacian` function
    cg_kwargs: dictionary
        Arguments passed to the :code:`cg` solver
    is_known: numpy.ndarray
        Binary mask of pixels for which to compute the laplacian matrix.
        Providing this parameter might improve performance if few pixels are unknown.

    Returns
    -------
    alpha: numpy.ndarray
        Estimated alpha matte

    Example
    -------
    >>> from pymatting import *
    >>> image = load_image("data/lemur/lemur.png", "RGB")
    >>> trimap = load_image("data/lemur/lemur_trimap.png", "GRAY")
    >>> alpha = estimate_alpha_cf(
    ...     image,
    ...     trimap,
    ...     laplacian_kwargs={"epsilon": 1e-6},
    ...     cg_kwargs={"maxiter":2000})
    Né   Úis_knownÚMr   é   )r   r   Úshaper   r   ÚcopyÚravelr   ÚdotÚnpÚclipÚreshape)ÚimageÚtrimapÚpreconditionerÚlaplacian_kwargsÚ	cg_kwargsÚhÚwÚis_fgÚis_bgr   Ú
is_unknownÚLÚL_UÚRÚmÚxÚalpha© r"   úH/tmp/pip-target-vg8gfxp4/lib/python/pymatting/alpha/estimate_alpha_cf.pyÚestimate_alpha_cf   s   &&r$   )Úpymatting.util.utilr   r   Ú pymatting.laplacian.cf_laplacianr   Úpymatting.preconditioner.icholr   Úpymatting.solver.cgr   Únumpyr   r$   r"   r"   r"   r#   Ú<module>   s    ÿ