Class SampleDimension

  • All Implemented Interfaces:
    Serializable

    public class SampleDimension
    extends Object
    implements Serializable
    Describes the data values in a coverage (the range). For a raster, a sample dimension is a band. A sample dimension can reserve some values for qualitative information like “this is a forest” and some other values for quantitative information like a temperature measurements.
    Example: an image of sea surface temperature (SST) could define the following categories:
    Example of categories in a sample dimension
    Values range Meaning
    [0] No data
    [1] Cloud
    [2] Land
    [10…210] Temperature to be converted into Celsius degrees through a linear equation
    In this example, sample values in range [10…210] define a quantitative category, while all others categories are qualitative.
    Relationship with metadata
    This class provides the same information than ISO 19115 org​.opengis​.metadata​.content​.Sample­Dimension, but organized in a different way. The use of the same name may seem a risk, but those two types are typically not used in same time.
    Since:
    1.0
    See Also:
    Serialized Form

    Defined in the sis-feature module

    • Constructor Detail

      • SampleDimension

        public SampleDimension​(GenericName name,
                               Number background,
                               Collection<? extends Category> categories)
        Creates a sample dimension with the specified name and categories. The sample dimension name is used as a way to perform a band select by using human comprehensible descriptions instead of numbers. The background value is used for filling empty space in map reprojections. The background value (if specified) should be the value of a qualitative category present in the categories collection, but this is not mandatory.

        Note that Sample­Dimension​.Builder provides a more convenient way to create sample dimensions.

        Parameters:
        name - an identification for the sample dimension.
        background - the background value, or null if none.
        categories - the list of categories. May be empty if none.
    • Method Detail

      • getName

        public GenericName getName()
        Returns an identification for this sample dimension. This is typically used as a way to perform a band select by using human comprehensible descriptions instead of just numbers. Web Coverage Service (WCS) can use this name in order to perform band sub-setting as directed from a user request.
        Returns:
        an identification of this sample dimension.
        See Also:
        Range­Dimension​.get­Sequence­Identifier()
      • getCategories

        public List<Category> getCategories()
        Returns all categories in this sample dimension. Note that a Category object may apply to an arbitrary range of sample values. Consequently, the first element in this collection may not be directly related to the sample value 0.
        Returns:
        the list of categories in this sample dimension, or an empty list if none.
      • getBackground

        public Optional<Number> getBackground()
        Returns the background value. If this sample dimensions has quantitative categories, then the background value should be one of the value returned by get­No­Data­Values(). However this is not mandatory.
        Returns:
        the background value, typically (but not necessarily) one of get­No­Data­Values().
      • getNoDataValues

        public Set<Number> getNoDataValues()
        Returns the values to indicate "no data" for this sample dimension. If the sample dimension describes converted values, then the "no data values" are NaN values.
        Returns:
        the values to indicate no data values for this sample dimension, or an empty set if none.
        Throws:
        Illegal­State­Exception - if this method can not expand the range of no data values, for example because some ranges contain an infinite amount of values.
      • getSampleRange

        public Optional<NumberRange<?>> getSampleRange()
        Returns the range of values occurring in this sample dimension. The range delimits sample values that can be converted into real values using the transfer function. If that function is identity, then the values are already real values and the range may be an instance of Measurement­Range (i.e. a number range with units of measurement).
        Returns:
        the range of sample values in this sample dimension.
      • getMeasurementRange

        public Optional<MeasurementRange<?>> getMeasurementRange()
        Returns the range of values after conversions by the transfer function. This range is absent if there is no transfer function.
        Returns:
        the range of values after conversion by the transfer function.
        See Also:
        get­Units()
      • getTransferFunction

        public Optional<MathTransform1D> getTransferFunction()
        Returns the transfer function from sample values to real values. This method returns a transform expecting sample values as input and computing real values as output. The output units of measurement is given by get­Units().

        This transform takes care of converting all "no data values" into Na­N values. The transfer­Function.inverse() transform is capable to differentiate those Na­N values and get back the original sample value.

        Returns:
        the transfer function from sample to real values. May be absent if this sample dimension does not define any transform (which is not the same that defining an identity transform).
      • forConvertedValues

        public SampleDimension forConvertedValues​(boolean converted)
        Returns a sample dimension that describes real values or sample values, depending if converted is true or false respectively. If there is no transfer function, then this method returns this.
        Parameters:
        converted - true for a sample dimension describing converted values, or false for a sample dimension describing packed values.
        Returns:
        a sample dimension describing converted or packed values, depending on converted argument value. May be this but never null.
        See Also:
        Grid­Coverage​.for­Converted­Values(boolean)
      • hashCode

        public int hashCode()
        Returns a hash value for this sample dimension.
        Overrides:
        hash­Code in class Object
      • equals

        public boolean equals​(Object object)
        Compares the specified object with this sample dimension for equality.
        Overrides:
        equals in class Object
        Parameters:
        object - the object to compare with.
        Returns:
        true if the given object is equals to this sample dimension.
      • toString

        public String toString()
        Returns a string representation of this sample dimension. This string is for debugging purpose only and may change in future version.
        Overrides:
        to­String in class Object
        Returns:
        a string representation of this sample dimension for debugging purpose.
      • toString

        @Debug
        public static String toString​(Locale locale,
                                      SampleDimension... dimensions)
        Returns a string representation of the given sample dimensions. This string is for debugging purpose only and may change in future version.
        Parameters:
        locale - the locale to use for formatting texts.
        dimensions - the sample dimensions to format.
        Returns:
        a string representation of the given sample dimensions for debugging purpose.