Collaboration diagram for osgEarth::GeoImage:

Public Member Functions
	GeoImage ()
	GeoImage (osg::Image *image, const GeoExtent &extent)
bool	valid () const
osg::Image *	getImage () const
const GeoExtent &	getExtent () const
const SpatialReference *	getSRS () const
GeoImage	crop (const GeoExtent &extent, bool exact=false, unsigned int width=0, unsigned int height=0) const
GeoImage	reproject (const SpatialReference to_srs, const GeoExtent to_extent=0, unsigned int width=0, unsigned int height=0) const
GeoImage	addTransparentBorder (bool leftBorder=true, bool rightBorder=true, bool bottomBorder=true, bool topBorder=true)
osg::Image *	takeImage ()
double	getUnitsPerPixel () const
Static Public Attributes
static GeoImage	INVALID
Private Attributes
osg::ref_ptr< osg::Image >	_image
GeoExtent	_extent

Detailed Description

A georeferenced image; i.e. an osg::Image and an associated GeoExtent with SRS.

Definition at line 234 of file GeoData.

Constructor & Destructor Documentation

GeoImage::GeoImage ( )

Construct an empty (invalid) geoimage.

Definition at line 483 of file GeoData.cpp.

                   :
_image(0L),
_extent( GeoExtent::INVALID )
{
    //nop
}

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GeoImage::GeoImage	(	osg::Image *	image,
		const GeoExtent &	extent
	)

Constructs a new goereferenced image.

Definition at line 491 of file GeoData.cpp.

                                                             :
_image(image),
_extent(extent)
{
    //NOP
}

Member Function Documentation

GeoImage GeoImage::addTransparentBorder	(	bool	leftBorder = `true`,
		bool	rightBorder = `true`,
		bool	bottomBorder = `true`,
		bool	topBorder = `true`
	)

Adds a one-pixel transparent border around an image.

Definition at line 575 of file GeoData.cpp.

{
    unsigned int buffer = 1;

    unsigned int newS = _image->s();
    if (leftBorder) newS += buffer;
    if (rightBorder) newS += buffer;

    unsigned int newT = _image->t();
    if (topBorder)    newT += buffer;
    if (bottomBorder) newT += buffer;

    osg::Image* newImage = new osg::Image;
    newImage->allocateImage(newS, newT, _image->r(), _image->getPixelFormat(), _image->getDataType(), _image->getPacking());
    newImage->setInternalTextureFormat(_image->getInternalTextureFormat());
    memset(newImage->data(), 0, newImage->getImageSizeInBytes());
    unsigned startC = leftBorder ? buffer : 0;
    unsigned startR = bottomBorder ? buffer : 0;
    ImageUtils::copyAsSubImage(_image.get(), newImage, startC, startR );

    //double upp = getUnitsPerPixel();
    double uppw = _extent.width() / (double)_image->s();
        double upph = _extent.height() / (double)_image->t();

    double xmin = leftBorder ? _extent.xMin() - buffer * uppw : _extent.xMin();
    double ymin = bottomBorder ? _extent.yMin() - buffer * upph : _extent.yMin();
    double xmax = rightBorder ? _extent.xMax() + buffer * uppw : _extent.xMax();
    double ymax = topBorder ? _extent.yMax() + buffer * upph : _extent.yMax();

    return GeoImage(newImage, GeoExtent(getSRS(), xmin, ymin, xmax, ymax));
}

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GeoImage GeoImage::crop	(	const GeoExtent &	extent,
		bool	exact = `false`,
		unsigned int	width = `0`,
		unsigned int	height = `0`
	)		const

Crops the image to a new geospatial extent.

Parameters:

extent	New extent to which to crop the image.
exact	If "exact" is true, the output image will have exactly the extents requested; this process may require resampling and will therefore be more expensive. If "exact" is false, we do a simple crop of the image that is rounded to the nearest pixel. The resulting extent will be close but usually not exactly what was requested - however, this method is faster.
width,height	New pixel size for the output image. By default, the method will automatically calculate a new pixel size.

Definition at line 521 of file GeoData.cpp.

{
    //Check for equivalence
    if ( extent.getSRS()->isEquivalentTo( getSRS() ) )
    {
        //If we want an exact crop or they want to specify the output size of the image, use GDAL
        if (exact || width != 0 || height != 0 )
        {
            OE_DEBUG << "[osgEarth::GeoImage::crop] Performing exact crop" << std::endl;

            //Suggest an output image size
            if (width == 0 || height == 0)
            {
                double xRes = (getExtent().xMax() - getExtent().xMin()) / (double)_image->s();
                double yRes = (getExtent().yMax() - getExtent().yMin()) / (double)_image->t();

                width =  osg::maximum(1u, (unsigned int)((extent.xMax() - extent.xMin()) / xRes));
                height = osg::maximum(1u, (unsigned int)((extent.yMax() - extent.yMin()) / yRes));

                OE_DEBUG << "[osgEarth::GeoImage::crop] Computed output image size " << width << "x" << height << std::endl;
            }

            //Note:  Passing in the current SRS simply forces GDAL to not do any warping
            return reproject( getSRS(), &extent, width, height);
        }
        else
        {
            OE_DEBUG << "[osgEarth::GeoImage::crop] Performing non-exact crop " << std::endl;
            //If an exact crop is not desired, we can use the faster image cropping code that does no resampling.
            double destXMin = extent.xMin();
            double destYMin = extent.yMin();
            double destXMax = extent.xMax();
            double destYMax = extent.yMax();

            osg::Image* new_image = ImageUtils::cropImage(
                _image.get(),
                _extent.xMin(), _extent.yMin(), _extent.xMax(), _extent.yMax(),
                destXMin, destYMin, destXMax, destYMax );

            //The destination extents may be different than the input extents due to not being able to crop along pixel boundaries.
            return new_image?
                GeoImage( new_image, GeoExtent( getSRS(), destXMin, destYMin, destXMax, destYMax ) ) :
                GeoImage::INVALID;
        }
    }
    else
    {
        //TODO: just reproject the image before cropping
        OE_NOTICE << "[osgEarth::GeoImage::crop] Cropping extent does not have equivalent SpatialReference" << std::endl;
        return GeoImage::INVALID;
    }
}

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const GeoExtent & GeoImage::getExtent ( ) const

Gets the geospatial extent of the image.

Definition at line 509 of file GeoData.cpp.

                          {
    return _extent;
}

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osg::Image * GeoImage::getImage ( ) const

Gets a pointer to the underlying OSG image.

Definition at line 499 of file GeoData.cpp.

                         {
    return _image.get();
}

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const SpatialReference * GeoImage::getSRS ( ) const

Shortcut to get the spatial reference system describing the projection of the image.

Definition at line 504 of file GeoData.cpp.

                       {
    return _extent.getSRS();
}

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double GeoImage::getUnitsPerPixel ( ) const

Gets the units per pixel of this geoimage

Definition at line 514 of file GeoData.cpp.

                                 {
        double uppw = _extent.width() / (double)_image->s();
        double upph = _extent.height() / (double)_image->t();
        return (uppw + upph) / 2.0;
}

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GeoImage GeoImage::reproject	(	const SpatialReference *	to_srs,
		const GeoExtent *	to_extent = `0`,
		unsigned int	width = `0`,
		unsigned int	height = `0`
	)		const

Warps the image into a new spatial reference system.

Parameters:

to_srs	SRS into which to warp the image.
to_extent	Supply this extent if you wish to warp AND crop the image in one step. This is faster than calling reproject() and then crop().
width,height	New pixel size for the output image. Be default, the method will automatically calculate a new pixel size.

Definition at line 930 of file GeoData.cpp.

{  
    GeoExtent destExtent;
    if (to_extent)
    {
        destExtent = *to_extent;
    }
    else
    {
         destExtent = getExtent().transform(to_srs);    
    }

    osg::Image* resultImage = 0L;

    if ( getSRS()->isUserDefined() || to_srs->isUserDefined() ||
        ( getSRS()->isMercator() && to_srs->isGeographic() ) ||
        ( getSRS()->isGeographic() && to_srs->isMercator() ) )
    {
        // if either of the SRS is a custom projection, we have to do a manual reprojection since
        // GDAL will not recognize the SRS.
        resultImage = manualReproject(getImage(), getExtent(), *to_extent, width, height);
    }
    else
    {
        // otherwise use GDAL.
        resultImage = reprojectImage(getImage(),
            getSRS()->getWKT(),
            getExtent().xMin(), getExtent().yMin(), getExtent().xMax(), getExtent().yMax(),
            to_srs->getWKT(),
            destExtent.xMin(), destExtent.yMin(), destExtent.xMax(), destExtent.yMax(),
            width, height);
    }   
    return GeoImage(resultImage, destExtent);
}