U !?hc@sZddlmZddlmZddlmZddlZddlZ dddddd gd ddiifd d Z dS) )ichol)sparse_conv_matrix_with_offsets)cgNgh㈵>)r)r)rr)rrFc Cs<|j\} } } |j| | fkst| | } |}d}|D]f\}}t| | ddgd|gd|g}|jtj|t |||}|dkr|n||}~~q6tj |dgd|gg}~tj tj|tjd|gg}|j||}| ~t |f|}|dkr|n|}|dkr(|n|}t| D]}|dddd|f}|j|}|dddd|f}|dddd|f}t ||g}t||f|||d| }|d| | | |dddd|f<|| d| | |dddd|f<q8t |dd}t |dd}|r8||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)Zx0Mrtol)shapeAssertionErrorflattenrTdotscipysparseZdiagsnpabsZbmatZsum_duplicatesrcopyrangeZ concatenaterZreshapeZclip) imagealphaZregularizationrZ neighborsZreturn_backgroundZforeground_guessZbackground_guessZ ichol_kwargsZ cg_kwargshwdnaSZdxZdyDZS2VUA precondition foreground backgroundZchannelZ image_channelbZf0Zb0Zfbr$]/var/www/html/venv/lib/python3.8/site-packages/pymatting/foreground/estimate_foreground_cf.pyestimate_foreground_cfsB;  *&   &*r&) Zpymatting.preconditioner.icholrZpymatting.util.utilrZpymatting.solver.cgrZ scipy.sparsernumpyrr&r$r$r$r%s