defects.py

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#
# LSST Data Management System
#
# Copyright 2008-2017  AURA/LSST.
#
# This product includes software developed by the
# LSST Project (http://www.lsst.org/).
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the LSST License Statement and
# the GNU General Public License along with this program.  If not,
# see <https://www.lsstcorp.org/LegalNotices/>.
#
"""Support for image defects"""

import lsst.geom
import lsst.pex.policy as policy
from . import Defect


def policyToBadRegionList(policyFile):
    """Given a Policy file describing a CCD's bad pixels, return a vector of BadRegion::Ptr"""

    badPixelsPolicy = policy.Policy.createPolicy(policyFile)
    badPixels = []

    if badPixelsPolicy.exists("Defects"):
        d = badPixelsPolicy.getArray("Defects")
        for reg in d:
            x0 = reg.get("x0")
            width = reg.get("width")
            if not width:
                x1 = reg.get("x1")
                width = x1 - x0 - 1

            y0 = reg.get("y0")
            if reg.exists("height"):
                height = reg.get("height")
            else:
                y1 = reg.get("y1")
                height = y1 - y0 - 1

            bbox = lsst.geom.BoxI(lsst.geom.PointI(x0, y0), lsst.geom.ExtentI(width, height))
            badPixels.append(Defect(bbox))

    return badPixels