Source code for pysap.utils

# -*- coding: utf-8 -*-
##########################################################################
# pySAP - Copyright (C) CEA, 2017 - 2018
# Distributed under the terms of the CeCILL-B license, as published by
# the CEA-CNRS-INRIA. Refer to the LICENSE file or to
# http://www.cecill.info/licences/Licence_CeCILL-B_V1-en.html
# for details.
##########################################################################

"""
A module with common functions to list and load transformations.
"""

# System import
import os
import shutil
import tempfile

# Package import
import pysap.extensions.transform
from pysap.base.transform import WaveletTransformBase


AVAILABLE_TRANSFORMS = sorted(WaveletTransformBase.REGISTRY.keys())



[docs]def wavelist(family=None):
    """ List/sort all available transforms.

    Parameters
    ----------
    family: str or list of str, default None
        the family wave family name.

    Returns
    -------
    transforms: dict
        the requested transforms.
    """
    if family is not None and not isinstance(family, list):
        family = [family]
    transforms = {}
    for key in AVAILABLE_TRANSFORMS:
        trf = WaveletTransformBase.REGISTRY[key]
        if family is None:
            transforms.setdefault(trf.__family__, []).append(key)
            continue
        if trf.__family__ in family:
            transforms.setdefault(trf.__family__, []).append(key)
    return transforms




[docs]def load_image(image_path):
    """ Load an image.

    Parameters
    ----------
    image_path: str
        the image path.

    Returns
    -------
    image: Image
        the loaded image.
    """
    image = pysap.io.load(image_path)
    return image




[docs]def save_image(image, image_path):
    """ Save an image.

    Parameters
    ----------
    image: Image
        the image to be saved.
    image_path: str
        the image path.
    """
    pysap.io.save(image, image_path)




[docs]def load_transform(name):
    """ Load a transformation using his name.

    All the available transfroms are stored in the 'pysap.AVAILABLE_TRANSFORMS'
    parameter.

    Parameters
    ----------
    name: str
        the name of the desired transformation.

    Returns
    -------
    transform: WaveletTransformBase
        the transformation.
    """
    if name not in WaveletTransformBase.REGISTRY:
        raise ValueError("Unknown transform '{0}'. Allowed transforms are: "
                         "{1}.".format(name, AVAILABLE_TRANSFORMS))
    return WaveletTransformBase.REGISTRY[name]




[docs]class TempDir(object):
    """ Create a tempdir with the with synthax.
    """
    def __init__(self, isap=False):
        """ Initialize the TempDir class.

        Parameters
        ----------
        isap: bool, default False
            if set, generates a temporary folder compatible with ISAP.
        """
        self.path = None
        self.isap = isap
        return

    def __enter__(self):
        if self.isap:
            self.path = self._mkdtemp_isap()
        else:
            self.path = tempfile.mkdtemp()
        return self.path

    def __exit__(self, type, value, traceback):
        if self.path is not None:
            shutil.rmtree(self.path)


[docs]    def _mkdtemp_isap(self):
        """ Method to generate a temporary folder compatible with the ISAP
        implementation.

        If 'jpg' or 'pgm' (with any case for each letter) are in the pathname,
        it will corrupt the format detection in ISAP.

        Returns
        -------
        tmpdir: str
            the generated ISAP compliant temporary folder.
        """
        tmpdir = None
        while (tmpdir is None or "pgm" in tmpdir.lower()
                or "jpg" in tmpdir.lower()):
            if tmpdir is not None and os.path.exists(tmpdir):
                os.rmdir(tmpdir)
            tmpdir = tempfile.mkdtemp()
        return tmpdir