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    \                 @   sj   d dl mZ d dlZddlmZ ddlmZmZ dddgZ	d	d
 Z
dd Zdd ZdddZdddZdS )    )divisionN   )dtype_range)skimage_deprecationwarncompare_msecompare_nrmsecompare_psnrc             C   s   | j |j kstddS )z3Raise an error if the shape and dtype do not match.z+Input images must have the same dimensions.N)shape
ValueError)im1im2 r   =lib/python3.7/site-packages/skimage/measure/simple_metrics.py_assert_compatible   s    r   c             C   s8   t | j|jt j}t j| |d} t j||d}| |fS )zAPromote im1, im2 to nearest appropriate floating point precision.)dtype)npZresult_typer   Zfloat32Zasarray)r   r   Z
float_typer   r   r   
_as_floats   s    r   c             C   s2   t | | t| |\} }tjt| | tjdS )zCompute the mean-squared error between two images.

    Parameters
    ----------
    im1, im2 : ndarray
        Image.  Any dimensionality.

    Returns
    -------
    mse : float
        The mean-squared error (MSE) metric.

    )r   )r   r   r   meanZsquarefloat64)r   r   r   r   r   r      s    
	Euclideanc             C   s   t | | t| |\} }| }|dkrDttj| |  tjd}n4|dkr^|  |   }n|dkrp|  }nt	dtt
| || S )aQ  Compute the normalized root mean-squared error (NRMSE) between two
    images.

    Parameters
    ----------
    im_true : ndarray
        Ground-truth image.
    im_test : ndarray
        Test image.
    norm_type : {'Euclidean', 'min-max', 'mean'}
        Controls the normalization method to use in the denominator of the
        NRMSE.  There is no standard method of normalization across the
        literature [1]_.  The methods available here are as follows:

        - 'Euclidean' : normalize by the averaged Euclidean norm of
          ``im_true``::

              NRMSE = RMSE * sqrt(N) / || im_true ||

          where || . || denotes the Frobenius norm and ``N = im_true.size``.
          This result is equivalent to::

              NRMSE = || im_true - im_test || / || im_true ||.

        - 'min-max'   : normalize by the intensity range of ``im_true``.
        - 'mean'      : normalize by the mean of ``im_true``

    Returns
    -------
    nrmse : float
        The NRMSE metric.

    References
    ----------
    .. [1] https://en.wikipedia.org/wiki/Root-mean-square_deviation

    Z	euclidean)r   zmin-maxr   zUnsupported norm_type)r   r   lowerr   Zsqrtr   r   maxminr   r   )im_trueim_testZ	norm_typeZdenomr   r   r   r   /   s    &

c             C   s   t | | |dkrz| j|jkr&td t| jj \}}t| t|  }}||ks\||k rdtd|dkrr|}n|| }t	| |\} }t
| |}dt|d |  S )a#   Compute the peak signal to noise ratio (PSNR) for an image.

    Parameters
    ----------
    im_true : ndarray
        Ground-truth image.
    im_test : ndarray
        Test image.
    data_range : int
        The data range of the input image (distance between minimum and
        maximum possible values).  By default, this is estimated from the image
        data-type.

    Returns
    -------
    psnr : float
        The PSNR metric.

    References
    ----------
    .. [1] https://en.wikipedia.org/wiki/Peak_signal-to-noise_ratio

    NzCInputs have mismatched dtype.  Setting data_range based on im_true.zrim_true has intensity values outside the range expected for its data type.  Please manually specify the data_ranger   
   r   )r   r   r   r   typer   r   r   r   r   r   Zlog10)r   r   Z
data_rangeZdminZdmaxZtrue_minZtrue_maxerrr   r   r   r	   d   s    

)r   )N)Z
__future__r   Znumpyr   Z
util.dtyper   Z_shared.utilsr   r   __all__r   r   r   r   r	   r   r   r   r   <module>   s   
5