Package com.luciad.format.ecw

Class TLcdECWModelDecoder

java.lang.Object
com.luciad.format.ecw.TLcdECWModelDecoder
All Implemented Interfaces:
ILcdMetadataDecoder, ILcdModelDecoder
@LcdService(service=ILcdModelDecoder.class, priority=20000) public class TLcdECWModelDecoder extends Object implements ILcdModelDecoder, ILcdMetadataDecoder
This model decoder decodes georeferenced ER Mapper ECW (Enhanced Compression Wavelet) files

Input files

File Required Entry point Description
*.ecw x x ECW file containing the raster data and possibly specifying a model reference and raster bounds using embedded GeoTIFF tags
*.ers

ERS file specifying a model reference and raster bounds
*.tab

TAB file specifying a model reference and raster bounds

If none of the files specify a model reference, the model reference is obtained from an ILcdModelReferenceDecoder. The default reference decoder set on this model decoder is based on all model reference decoders annotated with the LcdService annotation, and can handle

If this fails, the decoder's default model reference is returned. Unless set by the user, the default model reference is null.

If none of the files specify raster bounds, it is retrieved from the bounds property of this decoder.

Supported file transfer protocols

As random access to the data is required, this decoder only reads from files. So it can for example not read from an InputStream, from a http connection or from an image file inside a jar file.

Model structure

  • This model decoder creates a model per ECW file.
  • All models returned by this model decoder implement ILcd2DBoundsIndexedModel.

Model descriptor

  • All models returned by this model decoder have a TLcdECWModelDescriptor.
  • The type name of the model descriptor is the display name of this decoder.

Model reference

  • This decoder retrieves the model references embedded in the ECW file.
  • It is possible to specify a default reference for files from which the reference information is mssing.
  • A custom reference decoder can also be installed.

Model elements

  • Each decoded model contains one object: an ALcdImage (and ILcdMultilevelRaster) instance.

Useful settings

  • The property defaultValue allows the specify the default value that is assigned to decoded rasters.

Sample code


 ILcdModelDecoder decoder =
   new TLcdECWModelDecoder();

 ILcdModel model = decoder.decode("raster.ecw");

Performance tips

  • The decoded rasters load their data lazily. The encoding parameters of the ECW file may affect the run-time performance.

Thread safety

  • The decoding of models is thread-safe, as long as no properties are changed during the decoding.
  • The decoded models are thread-safe for read access.

Supported versions and specifications

  • ECW SDK, Release 6.1.0

Known limitations

  • Some rare EPSG model references are not supported.

Requirements

  • This decoder is part of the Advanced Raster Connectors component.
  • The native ECW library has to be available in order to be able to use this decoder. Note that on Windows systems, this library requires an up-to-date version of the Microsoft Visual C++ 2017 redistributable.

  • Field Details

  • Constructor Details

    • TLcdECWModelDecoder

      public TLcdECWModelDecoder()
      Creates a new TLcdECWModelDecoder, with a globally shared buffer for caching tiles.
      See Also:

    • TLcdECWModelDecoder

      public TLcdECWModelDecoder(ILcdBuffer aBuffer)
      Creates a new TLcdECWModelDecoder with the given buffer.
      Parameters:
      aBuffer - the buffer in which pixel data can be decoded and cached.

    • TLcdECWModelDecoder

      public TLcdECWModelDecoder(ILcdBuffer aBuffer, ILcdModelReferenceDecoder aModelReferenceDecoder)

      Creates a new TLcdECWModelDecoder with the given buffer and model reference decoder.

      Important: The parameter aBuffer is no longer used and has no effect on the functionality of this decoder.

      Parameters:
      aBuffer - the buffer in which pixel data can be decoded and cached.
      aModelReferenceDecoder - the model reference decoder.

    • TLcdECWModelDecoder

      public TLcdECWModelDecoder(ILcdBuffer aBuffer, ILcdModelReferenceDecoder aModelReferenceDecoder, int aDefaultValue)

      Creates a new TLcdECWModelDecoder with the given buffer, model reference decoder, and default value.

      Important: The parameter aBuffer is no longer used and has no effect on the functionality of this decoder.

      Parameters:
      aBuffer - the buffer in which pixel data can be decoded and cached.
      aModelReferenceDecoder - the model reference decoder.
      aDefaultValue - the default pixel value.

    • TLcdECWModelDecoder

      public TLcdECWModelDecoder(ILcdBuffer aBuffer, ILcdModelReference aDefaultModelReference)

      Creates a new TLcdECWModelDecoder with the given buffer and default model reference.

      Important: The parameter aBuffer is no longer used and has no effect on the functionality of this decoder.

      Parameters:
      aBuffer - the buffer in which pixel data can be decoded and cached.
      aDefaultModelReference - the default model reference.

    • TLcdECWModelDecoder

      public TLcdECWModelDecoder(ILcdBuffer aBuffer, ILcdModelReference aDefaultModelReference, int aDefaultValue)

      Creates a new TLcdECWModelDecoder with the given buffer, default model reference, and default value.

      Important: The parameter aBuffer is no longer used and has no effect on the functionality of this decoder.

      Parameters:
      aBuffer - the buffer in which pixel data can be decoded and cached.
      aDefaultModelReference - the default model reference.
      aDefaultValue - the default pixel value.

    • TLcdECWModelDecoder

      public TLcdECWModelDecoder(ILcdBuffer aBuffer, ILcdModelReferenceDecoder aModelReferenceDecoder, ILcdModelReference aDefaultModelReference, int aDefaultValue)

      Creates a new TLcdECWModelDecoder with the given properties.

      Important: The parameter aBuffer is no longer used and has no effect on the functionality of this decoder.

      Parameters:
      aBuffer - the buffer in which pixel data can be decoded and cached.
      aModelReferenceDecoder - the model reference decoder.
      aDefaultModelReference - the default model reference.
      aDefaultValue - the default pixel value.

  • Method Details

    • setModelReferenceDecoder

      public void setModelReferenceDecoder(ILcdModelReferenceDecoder aModelReferenceDecoder)
      Sets the model reference decoder that will be used for decoded models whose image files don't specify model references.
      Parameters:
      aModelReferenceDecoder - the model reference decoder.

    • getModelReferenceDecoder

      public ILcdModelReferenceDecoder getModelReferenceDecoder()
      Returns the model reference decoder that is used for decoded models whose image files don't specify model references. The default value supports WKT (*.prj), REF (*.ref), and EPSG (*.epsg).
      Returns:
      the model reference decoder used by this decoder
      See Also:

    • setDefaultModelReference

      public void setDefaultModelReference(ILcdModelReference aDefaultModelReference)
      Sets the default model reference that will be assigned to decoded models whose image files don't specify model references.
      Parameters:
      aDefaultModelReference - the default model reference.

    • getDefaultModelReference

      public ILcdModelReference getDefaultModelReference()
      Returns the default model reference that is assigned to decoded models whose image files don't specify model references.

    • setModelReference

      @Deprecated public void setModelReference(ILcdModelReference aDefaultModelReference)
      Deprecated.
      Use setDefaultModelReference(ILcdModelReference).

    • getModelReference

      @Deprecated public ILcdModelReference getModelReference()
      Deprecated.
      Use getDefaultModelReference().

    • setBounds

      public void setBounds(ILcdBounds aBounds)
      Sets the default model bounds that will be assigned to rasters of the decoded models whose image files don't specify bounds.
      Parameters:
      aBounds - the default model bounds.

    • getBounds

      public ILcdBounds getBounds()
      Sets the default model bounds that is assigned to rasters of the decoded models whose image files don't specify bounds.

    • setMaximumResidualTiePointError

      public void setMaximumResidualTiePointError(double aMaximumResidualTiePointError)
      Sets the maximum acceptable average residual error for tie points, when positioning rasters based TAB files instead of on scaling information.

      A raster is always positioned by means of an affine transformation in its coordinate system. For tie points that define an affine transformation, the residual error should therefore be 0. For tie points that define more complex, non-linear warping of the image, it will be larger than 0.

      The residual error is computed in image coordinates and expressed in pixels. The default is EPSILON.

      Parameters:
      aMaximumResidualTiePointError - the maximum residual error, expressed in pixels.

    • getMaximumResidualTiePointError

      public double getMaximumResidualTiePointError()
      Returns the maximum acceptable average residual error for tie points.

    • setDefaultValue

      public void setDefaultValue(int aDefaultValue)
      Sets the default pixel value that will be assigned to the rasters of the decoded models.
      Parameters:
      aDefaultValue - the default pixel value.
      See Also:

    • getDefaultValue

      public int getDefaultValue()
      Returns the default pixel value that is assigned to the rasters of the decoded models.

    • getMaxCacheSize

      public long getMaxCacheSize()
      Returns the maximum size of the ECW image cache.

      Note that the ECW image cache is currently shared between all ECW images.

      The default value is 64MB which should give good performance and reasonable memory usage in almost all cases.

      Returns:
      the maximum size in bytes

    • setMaxCacheSize

      public void setMaxCacheSize(long aMaxCacheSize)
      Sets the maximum size of the ECW image cache.
      Parameters:
      aMaxCacheSize - the maximum size in bytes
      See Also:

    • getDisplayName

      public String getDisplayName()
      Description copied from interface: ILcdModelDecoder
      Returns a short, displayable name for the format that is decoded by this ILcdModelDecoder.
      Specified by:
      getDisplayName in interface ILcdModelDecoder
      Returns:
      the displayable name of this ILcdModelDecoder.

    • canDecodeSource

      public boolean canDecodeSource(String aSourceName)
      Checks whether TLcdECWModelDecoder can decode the given data. The extension of the file name should be "ecw" or "ers".
      Specified by:
      canDecodeSource in interface ILcdModelDecoder
      Parameters:
      aSourceName - the name of the file that is to be decoded.
      Returns:
      true if TLcdECWModelDecoder can decode the data specified by the source name, false otherwise.
      See Also:

    • decode

      public ILcdModel decode(String aSourceName) throws IOException
      Description copied from interface: ILcdModelDecoder
      Creates a new model from the given data source.
      Specified by:
      decode in interface ILcdModelDecoder
      Parameters:
      aSourceName - the data source to be decoded; typically a file name or a URL.
      Returns:
      A model containing the decoded data. While null is allowed, implementors are advised to throw an error instead.
      Throws:
      IOException - for any exceptions caused by IO problems or invalid data. Since decoding invalid data almost always results in RunTimeExceptions (NullPointerException, IndexOutOfBoundsException, IllegalArgumentException, ...) on unexpected places, implementations are advised to catch RuntimeExceptions in their decode() method, and wrap them into an IOException, as illustrated in the code snippet below. 
      
   public ILcdModel decode( String aSourceName ) throws IOException {
      try (InputStream input = fInputStreamFactory.createInputStream(aSourceName)) {
         // Perform decoding ...
      } catch (RuntimeException e) {
         throw new IOException(e);
      }
   }
      See Also:

    • canDecodeMetadata

      public boolean canDecodeMetadata(String aSourceName)
      Description copied from interface: ILcdMetadataDecoder
      Tells whether this metadata decoder can likely decode metadata for a given source name.
      Specified by:
      canDecodeMetadata in interface ILcdMetadataDecoder
      Parameters:
      aSourceName - the source name to decode metadata for
      Returns:
      true if this metadata decoder can decode metadata for the given source name, false otherwise

    • decodeMetadata

      public TLcdISO19115Metadata decodeMetadata(String aSourceName) throws IOException
      The ECW metadata has the following structure: 
       Metadata
   DataIdentification
     Citation
       Title=[ECW data file name, same as identifier code]
       Identifier
         Code=[ECW data file name]
   Describes
     MX_DataSet
       DataFile
         FileName=[ECW data file name]
       SupportFiles
         FileName
           Src=[TAB support file name]*
           Src=[ERS support file name]*
           Src=[REF support file name]*
           Src=[PRJ support file name]*

      Elements with a '*' are optional. All file names are without parent path, which is needed for portability.

      Both the identifier and title contain the data file name. The identifier is authoritative, the title is for display purposes.

      Specified by:
      decodeMetadata in interface ILcdMetadataDecoder
      Parameters:
      aSourceName - the source name to decode metadata from
      Returns:
      the ECW metadata, possibly null
      Throws:
      IOException - if the metadata cannot be decoded for some reason