o :ήcc@sVddlmZddlmZddlmZddlZddlZ ddgddddiifdd Z dS) )ichol)sparse_conv_matrix_with_offsets)cgNgh㈵>))r)r)rr)rrFc Cs:|j\} } } |j| | fksJ| | } |}d}|D]3\}}t| | ddgd|gd|g}|jtj|t |||}|durH|n||}~~qtj |dgd|gg}~tj tj|tjd|gg}|j||}| ~t |fi|}|dur|n| }|dur|n| }t| D]i}|dddd|f}|j|}|dddd|f}|dddd|f}t||g}t||f|||d| }|d| | | |dddd|f<|| d| | |dddd|f<qt|dd}t|dd}|r||fS|S)aEstimates the foreground of an image given alpha matte and image. This method is based on the publication :cite:`levin2007closed`. Parameters ---------- image: numpy.ndarray Input image with shape :math:`h \times w \times d` alpha: numpy.ndarray Input alpha matte with shape :math:`h \times w` regularization: float Regularization strength :math:`\epsilon`, defaults to :math:`10^{-5}` neighbors: list of tuples of ints List of relative positions that define the neighborhood of a pixel return_background: bool Whether to return the estimated background in addition to the foreground foreground_guess: numpy.ndarray An initial guess for the foreground image in order to accelerate convergence. Using input image by default. background_guess: numpy.ndarray An initial guess for the background image. Using input image by default. ichol_kwargs: dictionary Keyword arguments for the incomplete Cholesky preconditioner cg_kwargs: dictionary Keyword arguments for the conjugate gradient descent solver Returns ------- F: numpy.ndarray Extracted foreground B: numpy.ndarray Extracted background (not returned by default) Example ------- >>> from pymatting import * >>> image = load_image("data/lemur/lemur.png", "RGB") >>> alpha = load_image("data/lemur/lemur_alpha.png", "GRAY") >>> F = estimate_foreground_cf(image, alpha, return_background=False) >>> F, B = estimate_foreground_cf(image, alpha, return_background=True) See Also -------- stack_images: This function can be used to place the foreground on a new background. Ng?grr)x0Mrtol)shapeflattenrTdotscipysparsediagsnpabsbmatsum_duplicatesrcopyrange concatenaterreshapeclip) imagealpharegularizationr neighborsreturn_backgroundforeground_guessbackground_guess ichol_kwargs cg_kwargshwdnaSdxdyDS2VUA precondition foreground backgroundchannel image_channelbf0b0fbr9R/tmp/pip-target-vg8gfxp4/lib/python/pymatting/foreground/estimate_foreground_cf.pyestimate_foreground_cfsB ; *&  &(r;) pymatting.preconditioner.icholrpymatting.util.utilrpymatting.solver.cgr scipy.sparsernumpyrr;r9r9r9r:s