lsst::afw::image::ImageBaseFitsReader Class Reference

Base class for image FITS readers. More...

#include <ImageBaseFitsReader.h>

Inheritance diagram for lsst::afw::image::ImageBaseFitsReader:

Public Member Functions
	ImageBaseFitsReader (std::string const &fileName, int hdu=fits::DEFAULT_HDU)
	Construct a FITS reader object.
	ImageBaseFitsReader (fits::MemFileManager &manager, int hdu=fits::DEFAULT_HDU)
	Construct a FITS reader object.
	ImageBaseFitsReader (fits::Fits *fitsFile)
	Construct a FITS reader object.
	ImageBaseFitsReader (ImageBaseFitsReader const &)=delete
	ImageBaseFitsReader (ImageBaseFitsReader &&)=delete
ImageBaseFitsReader &	operator= (ImageBaseFitsReader const &)=delete
ImageBaseFitsReader &	operator= (ImageBaseFitsReader &&)=delete
std::string	readDType () const
	Read a string describing the pixel type of the on-disk image.
lsst::geom::Box2I	readBBox (ImageOrigin origin=PARENT)
	Read the bounding box of the on-disk image.
lsst::geom::Point2I	readXY0 (lsst::geom::Box2I const &bbox=lsst::geom::Box2I(), ImageOrigin origin=PARENT)
	Read the image origin from the on-disk image or a subimage thereof.
std::shared_ptr< daf::base::PropertyList >	readMetadata ()
	Read the image's FITS header.
template<typename T >
ndarray::Array< T, 2, 2 >	readArray (lsst::geom::Box2I const &bbox, ImageOrigin origin=PARENT, bool allowUnsafe=false)
	Read the image's data array.
int	getHdu () const noexcept
	Return the HDU this reader targets.
std::string	getFileName () const
	Return the name of the file this reader targets.

Protected Member Functions
	~ImageBaseFitsReader () noexcept

Friends
class	MaskedImageFitsReader

Detailed Description

Base class for image FITS readers.

This class should be considered an implementation detail of ImageFitsReader and MaskFitsReader that provides their common methods, not the definition of an interface.

Exception Safety

All ImageBaseFitsReader methods provide strong exception safety, but exceptions thrown by the internal fits::Fits object itself may change its status variable or HDU pointer; ImageBaseFitsReader guards against this by resetting those before any use of the Fits object.

Definition at line 47 of file ImageBaseFitsReader.h.

Constructor & Destructor Documentation

ImageBaseFitsReader() [1/5]

lsst::afw::image::ImageBaseFitsReader::ImageBaseFitsReader ( std::string const & fileName, int hdu = fits::DEFAULT_HDU )

explicit

Construct a FITS reader object.

Parameters

fileName	Name of a file to open.
hdu	HDU index, where 0 is the primary HDU and DEFAULT_HDU is the first non-empty HDU.

Definition at line 27 of file ImageBaseFitsReader.cc.

                                                                           :
    _ownsFitsFile(true),
    _hdu(0),
    _fitsFile(new fits::Fits(fileName, "r", fits::Fits::AUTO_CLOSE | fits::Fits::AUTO_CHECK))
{
    _fitsFile->setHdu(hdu);
    _fitsFile->checkCompressedImagePhu();
    _hdu = _fitsFile->getHdu();
}

ImageBaseFitsReader() [2/5]

lsst::afw::image::ImageBaseFitsReader::ImageBaseFitsReader ( fits::MemFileManager & manager, int hdu = fits::DEFAULT_HDU )

explicit

Construct a FITS reader object.

Parameters

manager	Memory block containing a FITS file.
hdu	HDU index, where 0 is the primary HDU and DEFAULT_HDU is the first non-empty HDU.

Definition at line 37 of file ImageBaseFitsReader.cc.

                                                                             :
    _ownsFitsFile(true),
    _hdu(0),
    _fitsFile(new fits::Fits(manager, "r", fits::Fits::AUTO_CLOSE | fits::Fits::AUTO_CHECK))
{
    _fitsFile->setHdu(hdu);
    _fitsFile->checkCompressedImagePhu();
    _hdu = _fitsFile->getHdu();
}

ImageBaseFitsReader() [3/5]

lsst::afw::image::ImageBaseFitsReader::ImageBaseFitsReader ( fits::Fits * fitsFile )

explicit

Construct a FITS reader object.

Parameters

fitsFile

Pointer to a CFITSIO file object. Lifetime will not be managed by the Reader object.

Definition at line 47 of file ImageBaseFitsReader.cc.

                                                            :
    _ownsFitsFile(false),
    _hdu(0),
    _fitsFile(fitsFile)
{
    if (_fitsFile) {
        if (_fitsFile->getHdu() == 0 && _fitsFile->getImageDim() == 0) {
            _fitsFile->setHdu(fits::DEFAULT_HDU);
        }
        _fitsFile->checkCompressedImagePhu();
        _hdu = _fitsFile->getHdu();
    }
}

ImageBaseFitsReader() [4/5]

lsst::afw::image::ImageBaseFitsReader::ImageBaseFitsReader ( ImageBaseFitsReader const & )

delete

ImageBaseFitsReader() [5/5]

lsst::afw::image::ImageBaseFitsReader::ImageBaseFitsReader ( ImageBaseFitsReader && )

delete

~ImageBaseFitsReader()

lsst::afw::image::ImageBaseFitsReader::~ImageBaseFitsReader ( )

protectednoexcept

Definition at line 61 of file ImageBaseFitsReader.cc.

                                                   {
    if (_ownsFitsFile) {
        delete _fitsFile;
    }
}

Member Function Documentation

getFileName()

std::string lsst::afw::image::ImageBaseFitsReader::getFileName ( ) const

inline

Return the name of the file this reader targets.

Definition at line 141 of file ImageBaseFitsReader.h.

{ return _fitsFile->getFileName(); }

getHdu()

int lsst::afw::image::ImageBaseFitsReader::getHdu ( ) const

inlinenoexcept

Return the HDU this reader targets.

Definition at line 136 of file ImageBaseFitsReader.h.

{ return _hdu; }

operator=() [1/2]

ImageBaseFitsReader & lsst::afw::image::ImageBaseFitsReader::operator= ( ImageBaseFitsReader && )

delete

operator=() [2/2]

ImageBaseFitsReader & lsst::afw::image::ImageBaseFitsReader::operator= ( ImageBaseFitsReader const & )

delete

readArray()

template<typename T >

template ndarray::Array< std::uint64_t, 2, 2 > lsst::afw::image::ImageBaseFitsReader::readArray	(	lsst::geom::Box2I const &	bbox,
		ImageOrigin	origin = PARENT,
		bool	allowUnsafe = false )

Read the image's data array.

Parameters

bbox	A bounding box used to defined a subimage, or an empty box (default) to read the whole image.
origin	Coordinate system convention for the given box.
allowUnsafe	Permit reading into the requested pixel type even when on-disk values may overflow or truncate.

Definition at line 171 of file ImageBaseFitsReader.cc.

                                                                         {
    checkFitsFile(_fitsFile);
    auto fullBBox = readBBox(origin);
    auto subBBox = bbox;
    if (subBBox.isEmpty()) {
        subBBox = fullBBox;
    } else if (!fullBBox.contains(subBBox)) {
        throw LSST_EXCEPT(
            pex::exceptions::LengthError,
            str(boost::format("Subimage box (%d,%d) %dx%d doesn't fit in image (%d,%d) %dx%d in HDU %d") %
                subBBox.getMinX() % subBBox.getMinY() % subBBox.getWidth() % subBBox.getHeight() %
                fullBBox.getMinX() % fullBBox.getMinY() % fullBBox.getWidth() % fullBBox.getHeight() % _hdu)
        );
    }
    fits::HduMoveGuard guard(*_fitsFile, _hdu);
    if (!allowUnsafe & !_fitsFile->checkImageType<T>()) {
        throw LSST_FITS_EXCEPT(
            fits::FitsTypeError, *_fitsFile,
            str(boost::format("Incompatible type for FITS image: on disk is %s (HDU %d), in-memory is %s. "
                              "Read with allowUnsafe=True to permit conversions that may overflow.") %
                _fitsFile->getImageDType() % _hdu % makeDTypeString<T>())
        );
    }
    ndarray::Array<T, 2, 2> result = ndarray::allocate(subBBox.getHeight(), subBBox.getWidth());
    ndarray::Vector<int, 2> offset = ndarray::makeVector(subBBox.getMinY() - fullBBox.getMinY(),
                                                         subBBox.getMinX() - fullBBox.getMinX());
    _fitsFile->readImage(result, offset);
    return result;
}

readBBox()

lsst::geom::Box2I lsst::afw::image::ImageBaseFitsReader::readBBox

(

ImageOrigin

origin = PARENT

)

Read the bounding box of the on-disk image.

Parameters

origin

Coordinate system convention for the returned box. If LOCAL, the returned box will always have a minimum of (0, 0).

Definition at line 86 of file ImageBaseFitsReader.cc.

                                                              {
    readMetadata();  // guarantees _bbox is initialized
    if (origin == LOCAL) {
        return lsst::geom::Box2I(lsst::geom::Point2I(), _bbox.getDimensions());
    }
    return _bbox;
}

readDType()

std::string lsst::afw::image::ImageBaseFitsReader::readDType

(

)

const

Read a string describing the pixel type of the on-disk image.

Returns

A string of the form [u](int|float)<bits> (e.g. "uint16", "float64").

Definition at line 80 of file ImageBaseFitsReader.cc.

                                               {
    checkFitsFile(_fitsFile);
    fits::HduMoveGuard guard(*_fitsFile, _hdu);
    return _fitsFile->getImageDType();
}

readMetadata()

std::shared_ptr< daf::base::PropertyList > lsst::afw::image::ImageBaseFitsReader::readMetadata

(

)

Read the image's FITS header.

Definition at line 105 of file ImageBaseFitsReader.cc.

                                                                     {
    checkFitsFile(_fitsFile);
    if (_metadata == nullptr) {
        fits::HduMoveGuard guard(*_fitsFile, _hdu);
        auto metadata = fits::readMetadata(*_fitsFile, /*strip=*/true);
        // One-use lambda avoids declare-then-initialize; see C++ Core Guidelines, ES28.
        auto computeShape = [this](){
            int nAxis = _fitsFile->getImageDim();
            if (nAxis == 2) {
                return _fitsFile->getImageShape<2>();
            }
            if (nAxis == 3) {
                ndarray::Vector<ndarray::Size, 3> shape3 = _fitsFile->getImageShape<3>();
                if (shape3[0] != 1) {
                    throw LSST_EXCEPT(
                        fits::FitsError,
                        str(boost::format("Error reading %s: HDU %d has 3rd dimension %d != 1") %
                            getFileName() % _hdu % shape3[0]));
                }
                return shape3.last<2>();
            }
            throw LSST_EXCEPT(
                fits::FitsError,
                str(boost::format("Error reading %s: HDU %d has %d dimensions") %
                    getFileName() % _hdu % nAxis)
            );
        };
        // Construct _bbox and check dimensions at the same time both to make
        // one less valid state for this class to be in and to make sure
        // the appropriate metadata is stripped before we ever return it.
        ndarray::Vector<ndarray::Size, 2> shape = computeShape();
        auto xy0 = afw::geom::getImageXY0FromMetadata(*metadata, detail::wcsNameForXY0, /*strip=*/true);
        _bbox = lsst::geom::Box2I(xy0, lsst::geom::Extent2I(shape[1], shape[0]));
        _metadata = std::move(metadata);
    }
    return _metadata;
}

readXY0()

lsst::geom::Point2I lsst::afw::image::ImageBaseFitsReader::readXY0	(	lsst::geom::Box2I const &	bbox = lsst::geom::Box2I(),
		ImageOrigin	origin = PARENT )

Read the image origin from the on-disk image or a subimage thereof.

Parameters

bbox	A bounding box used to defined a subimage, or an empty box (default) to use the whole image.
origin	Coordinate system convention for the given box. Ignored if bbox is empty.

Definition at line 94 of file ImageBaseFitsReader.cc.

                                                                                           {
    if (bbox.isEmpty()) {
        return readBBox().getMin();
    } else if (origin == PARENT) {
        return bbox.getMin();
    } else {
        auto full = readBBox();
        return full.getMin() + lsst::geom::Extent2I(bbox.getMin());
    }
}

Friends And Related Symbol Documentation

MaskedImageFitsReader

friend class MaskedImageFitsReader

friend

Definition at line 151 of file ImageBaseFitsReader.h.

---

The documentation for this class was generated from the following files:

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/afw/g5a732f18d5+53520f316c/include/lsst/afw/image/ImageBaseFitsReader.h
• /j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/afw/g5a732f18d5+53520f316c/src/image/ImageBaseFitsReader.cc