Package org.esa.snap.core.datamodel

Class PixelGeoCoding

  • All Implemented Interfaces:
    BasicPixelGeoCoding, GeoCoding
    @Deprecated
public class PixelGeoCoding
extends AbstractGeoCoding
implements BasicPixelGeoCoding
    Deprecated.
    since SNAP 8, use ComponentGeoCoding instead
    DEPRECATED!

    The PixelGeoCoding is an implementation of a GeoCoding which uses dedicated latitude and longitude bands in order to provide geographical positions for each pixel. Unlike the TiePointGeoCoding, which uses sub-sampled tie-point grids, the PixelGeoCoding class uses bands.

    This class is especially useful for high accuracy geo-coding, e.g. if geographical positions are computed for each pixel by an upstream orthorectification.

    While the implementation of the getGeoPos(PixelPos, GeoPos) is straight forward, the getPixelPos(GeoPos, PixelPos) uses two different search algorithms in order to find the corresponding geo-position for a given pixel:

    1. Search an N x N window around an estimated pixel position using the geo-coding of the source product (if any) or
    2. perform a quad-tree search if the source product has no geo-coding.

    Use instances of this class with care: The constructor fully loads the data given by the latitudes and longitudes bands and the valid mask (if any) into memory.

    Note (rq-20110526): A better implementation of the find pixel method could be something like:

    1. Create a coverage of the source region by means of largely overlapping image tiles (e.g. tile size of 100 pixels squared with an overlap of 25 pixels)
    2. For each tile create a rational function model of the (lon, lat) to (x, y) transformation, rotating to the (lon, lat) of the tile center
    3. Refine the accuracy of the selected rational function model until the accuracy goal (i.e. a certain RMSE) is reached
    4. Find all tiles {T1, T2, ...} that may include the (x, y) pixel coordinate of interest
    5. Select the tile T in {T1, T2, ...} where the the (x, y) result is nearest to (0, 0)
    6. Use the three closest pixels to compute the final (x, y)
    7. Keep all rational function approximations in a map and reuse them for subsequent calls.

    The advantage of this algorithm is that it obviously avoids problems related to the antimeridian and poles included in the source region.

    • Constructor Detail

      • PixelGeoCoding

        public PixelGeoCoding​(Band latBand,
                      Band lonBand,
                      String validMask,
                      int searchRadius)
        Deprecated.
        Constructs a new pixel-based geo-coding.

        Use with care: In contrast to the other constructor this one loads the data not until first access to getPixelPos(GeoPos, PixelPos) or getGeoPos(PixelPos, GeoPos).

        Parameters:
        latBand - the band providing the latitudes
        lonBand - the band providing the longitudes
        validMask - the valid mask expression used to identify valid lat/lon pairs, e.g. "NOT l1_flags.DUPLICATED". Can be null if a valid mask is not used.
        searchRadius - the search radius in pixels, shall depend on the actual spatial scene resolution, e.g. for 300 meter pixels a search radius of 5 is a good choice. This parameter is ignored if the source product is not geo-coded.

      • PixelGeoCoding

        public PixelGeoCoding​(Band latBand,
                      Band lonBand,
                      String validMask,
                      int searchRadius,
                      ProgressMonitor pm)
               throws IOException
        Deprecated.
        Constructs a new pixel-based geo-coding.

        Use with care: This constructor fully loads the data given by the latitudes and longitudes bands and the valid mask (if any) into memory.

        Parameters:
        latBand - the band providing the latitudes
        lonBand - the band providing the longitudes
        validMask - the valid mask expression used to identify valid lat/lon pairs, e.g. "NOT l1_flags.DUPLICATED". Can be null if a valid mask is not used.
        searchRadius - the search radius in pixels, shall depend on the actual spatial scene resolution, e.g. for 300 meter pixels a search radius of 5 is a good choice. This parameter is ignored if the source product is not geo-coded.
        pm - a monitor to inform the user about progress
        Throws:
        IOException - if an I/O error occurs while additional data is loaded from the source product

    • Method Detail

      • getRequiredMemory

        public static long getRequiredMemory​(Product product,
                                     boolean usesValidMask)
        Deprecated.
        Computes an estimation of the memory required to create an instance of this class for the given product. The estimation is returned in bytes.
        Returns:
        an estimation of the required memory in bytes

      • getPixelPosEstimator

        public GeoCoding getPixelPosEstimator()
        Deprecated.
        Gets the underlying geo-coding used as pixel position estimator.
        Specified by:
        getPixelPosEstimator in interface BasicPixelGeoCoding
        Returns:
        the underlying delegate geo-coding, can be null

      • getSearchRadius

        public int getSearchRadius()
        Deprecated.
        Gets the search radius used by this geo-coding.
        Specified by:
        getSearchRadius in interface BasicPixelGeoCoding
        Returns:
        the search radius in pixels

      • isCrossingMeridianAt180

        public boolean isCrossingMeridianAt180()
        Deprecated.
        Checks whether or not the longitudes of this geo-coding cross the +/- 180 degree meridian.
        Specified by:
        isCrossingMeridianAt180 in interface GeoCoding
        Returns:
        true, if so

      • canGetPixelPos

        public boolean canGetPixelPos()
        Deprecated.
        Checks whether or not this geo-coding can determine the pixel position from a geodetic position.
        Specified by:
        canGetPixelPos in interface GeoCoding
        Returns:
        true, if so

      • canGetGeoPos

        public boolean canGetGeoPos()
        Deprecated.
        Checks whether or not this geo-coding can determine the geodetic position from a pixel position.
        Specified by:
        canGetGeoPos in interface GeoCoding
        Returns:
        true, if so

      • getPixelPos

        public PixelPos getPixelPos​(GeoPos geoPos,
                            PixelPos pixelPos)
        Deprecated.
        Returns the pixel co-ordinates as x/y for a given geographical position given as lat/lon.
        Specified by:
        getPixelPos in interface GeoCoding
        Parameters:
        geoPos - the geographical position as lat/lon.
        pixelPos - an instance of Point to be used as return value. If this parameter is null, the method creates a new instance which it then returns.
        Returns:
        the pixel co-ordinates as x/y

      • getPixelPosUsingEstimator

        public void getPixelPosUsingEstimator​(GeoPos geoPos,
                                      PixelPos pixelPos)
        Deprecated.
        Returns the pixel co-ordinates as x/y for a given geographical position given as lat/lon.
        Parameters:
        geoPos - the geographical position as lat/lon.
        pixelPos - the return value.

      • getPixelPosUsingQuadTreeSearch

        public void getPixelPosUsingQuadTreeSearch​(GeoPos geoPos,
                                           PixelPos pixelPos)
        Deprecated.
        Returns the pixel co-ordinates as x/y for a given geographical position given as lat/lon. This algorithm
        Parameters:
        geoPos - the geographical position as lat/lon.
        pixelPos - the return value

      • getGeoPos

        public GeoPos getGeoPos​(PixelPos pixelPos,
                        GeoPos geoPos)
        Deprecated.
        Returns the latitude and longitude value for a given pixel co-ordinate.
        Specified by:
        getGeoPos in interface GeoCoding
        Parameters:
        pixelPos - the pixel's co-ordinates given as x,y
        geoPos - an instance of GeoPos to be used as return value. If this parameter is null, the method creates a new instance which it then returns.
        Returns:
        the geographical position as lat/lon.

      • equals

        public boolean equals​(Object o)
        Deprecated.
        Overrides:
        equals in class Object

      • hashCode

        public int hashCode()
        Deprecated.
        Overrides:
        hashCode in class Object

      • dispose

        public void dispose()
        Deprecated.
        Releases all of the resources used by this object instance and all of its owned children. Its primary use is to allow the garbage collector to perform a vanilla job.

        This method should be called only if it is for sure that this object instance will never be used again. The results of referencing an instance of this class after a call to dispose() are undefined.

        Specified by:
        dispose in interface GeoCoding

      • transferGeoCoding

        public boolean transferGeoCoding​(Scene srcScene,
                                 Scene destScene,
                                 ProductSubsetDef subsetDef)
        Deprecated.
        Transfers the geo-coding of the srcScene to the destScene with respect to the given subsetDef.
        Specified by:
        transferGeoCoding in class AbstractGeoCoding
        Parameters:
        srcScene - the source scene
        destScene - the destination scene
        subsetDef - the definition of the subset, may be null
        Returns:
        true, if the geo-coding could be transferred.

      • getDatum

        public Datum getDatum()
        Deprecated.
        Gets the datum, the reference point or surface against which GeoPos measurements are made.
        Specified by:
        getDatum in interface GeoCoding
        Returns:
        the datum