GDALUtils (WorldWindJava API)

java.lang.Object
- gov.nasa.worldwind.util.gdal.GDALUtils

```
public class GDALUtils
extends java.lang.Object
```
Worldwind users should install a binary edition of GDAL, including the Java interface (gdal.jar, gdalalljni.lib/libgdalalljni.so).
- The classpath used to build/execute Worldwind must include the location of the gdal.jar file.
- On Windows, the 'java.libary.path' property must be set to the location of the JNI shared library.
- In addition, if the DLLs are not in the same directory as the launched application, the PATH environment variable should be set to include the location of the shared libraries. Note that if 'java.library.path' is not explicitly set, the JVM's default includes PATH plus the current directory.
- On Linux, the LD_LIBRARY_PATH environment variable should be set to include the location of the JNI shared library. The JVM will include the paths in LD_LIBRARY_PATH in the 'java.library.path' property.
- Unless the GDAL_DATA environment variable is set, the GDAL data directory will be searched for, using the property "user.dir", and then in some standard locations.
- Unless the GDAL_DRIVER_PATH environment variable is set, the GDAL plugins direoctory will be searched for, using the property "user.dir", and then in some standard locations.

Field Summary

Fields
Modifier and Type	Field and Description
`static long`	`ALPHA_MASK`
`protected static byte`	`ALPHA_OPAQUE`
`protected static byte`	`ALPHA_TRANSPARENT`
`protected static java.lang.String`	`GDAL_DATA_PATH`
`protected static java.lang.String`	`GDAL_DRIVER_PATH`
`protected static java.util.concurrent.atomic.AtomicBoolean`	`gdalIsAvailable`
`protected static java.lang.String`	`JAVA_LIBRARY_PATH`

Constructor Summary

Constructors
Constructor and Description

GDALUtils()

Constructors
Constructor and Description
`GDALUtils()`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`protected static void`	`applyImageMask(byte[] alphaBand, java.nio.IntBuffer maskBand)`
`protected static void`	`applyImageMask(int[] alphaBand, java.nio.IntBuffer maskBand)`
`protected static void`	`applyImageMask(short[] alphaBand, java.nio.IntBuffer maskBand)`
`protected static java.lang.String`	`buildPathString(java.lang.String[] folders)`
`static double[]`	`calcGetGeoTransform(Sector sector, int width, int height)` Calculates geo-transform matrix for a north-up raster
`static boolean`	`canOpen(java.lang.Object source)` Checks if a data raster can is readable
`static DataRaster`	`composeDataRaster(org.gdal.gdal.Dataset ds, AVList params)`
`protected static DataRaster`	`composeImageDataRaster(org.gdal.gdal.Dataset ds, AVList params)` Opens image or elevation file, returns as a BufferedImage (even for elevations)
`protected static DataRaster`	`composeNonImageDataRaster(org.gdal.gdal.Dataset ds, AVList params)` The "composeDataRaster" method creates a ByteBufferRaster from an elevation (or non-image) Dataset.
`protected static java.lang.Double`	`convertStringToDouble(java.lang.String s)`
`static org.gdal.osr.SpatialReference`	`createGeographicSRS()`
`protected static java.awt.image.BufferedImage`	`detectVoidsAndMakeThemTransparent(java.awt.image.BufferedImage sourceImage)` Attempts to detect if there are any black\|white\|gray voids (also called black skirts) i n the image raster caused by inaccurate clipping.
`static int[]`	`extractBandOrder(org.gdal.gdal.Dataset ds, AVList params)`
`protected static java.nio.IntBuffer`	`extractImageMask(AVList params)`
`protected static void`	`extractMinMaxSampleValues(org.gdal.gdal.Dataset ds, org.gdal.gdal.Band band, AVList params)`
`static AVList`	`extractRasterParameters(org.gdal.gdal.Dataset ds)`
`static AVList`	`extractRasterParameters(org.gdal.gdal.Dataset ds, AVList params, boolean quickReadingMode)` Extracts raster parameters to an AVList
`protected static java.lang.String`	`findGdalDataFolder(java.lang.String dir)`
`protected static java.lang.String`	`findGdalPlugins(java.lang.String dir)`
`protected static java.lang.String`	`getCurrentDirectory()`
`static java.lang.String`	`getErrorMessage()`
`protected static LatLon`	`getLatLonForRasterPoint(double[] gt, int x, int y, org.gdal.osr.CoordinateTransformation ct)`
`protected static void`	`listAllRegisteredDrivers()`
`static org.gdal.gdal.Dataset`	`open(java.lang.Object source)` Opens image or elevation file, returns a DataSet object
`static org.gdal.gdal.Dataset`	`open(java.lang.Object source, boolean isSilentMode)` Opens image or elevation file, returns a DataSet object
`protected static void`	`scanFill(java.awt.image.BufferedImage sourceImage)`
`protected static boolean`	`setNoDataValue(org.gdal.gdal.Band band, java.lang.Double nodata)`
`protected static java.awt.image.BufferedImage`	`verticalFlip(java.awt.image.BufferedImage img)` Flips image raster vertically

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - ALPHA_MASK
```
public static long ALPHA_MASK
```
  - ALPHA_OPAQUE
```
protected static byte ALPHA_OPAQUE
```
  - ALPHA_TRANSPARENT
```
protected static byte ALPHA_TRANSPARENT
```
  - GDAL_DATA_PATH
```
protected static final java.lang.String GDAL_DATA_PATH
```
    See Also:
    
    Constant Field Values
  - GDAL_DRIVER_PATH
```
protected static final java.lang.String GDAL_DRIVER_PATH
```
    See Also:
    
    Constant Field Values
  - gdalIsAvailable
```
protected static final java.util.concurrent.atomic.AtomicBoolean gdalIsAvailable
```
  - JAVA_LIBRARY_PATH
```
protected static final java.lang.String JAVA_LIBRARY_PATH
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - GDALUtils
```
public GDALUtils()
```
- Method Detail
  - applyImageMask
```
protected static void applyImageMask(byte[] alphaBand,
                                     java.nio.IntBuffer maskBand)
```
  - applyImageMask
```
protected static void applyImageMask(int[] alphaBand,
                                     java.nio.IntBuffer maskBand)
```
  - applyImageMask
```
protected static void applyImageMask(short[] alphaBand,
                                     java.nio.IntBuffer maskBand)
```
  - buildPathString
```
protected static java.lang.String buildPathString(java.lang.String[] folders)
```
  - calcGetGeoTransform
```
public static double[] calcGetGeoTransform(Sector sector,
                                           int width,
                                           int height)
                                    throws java.lang.IllegalArgumentException
```
    Calculates geo-transform matrix for a north-up raster
    
    Parameters:
    
    sector - Geographic area, a Sector
    
    width - none-zero width of a raster
    
    height - none-zero height of a raster
    
    Returns:
    
    an array of 6 doubles that contain a geo-transform matrix
    
    Throws:
    
    java.lang.IllegalArgumentException - if sector is null, or raster size is zero
  - canOpen
```
public static boolean canOpen(java.lang.Object source)
```
    Checks if a data raster can is readable
    
    Parameters:
    
    source - the location of the local file, expressed as either a String path, a File, or a file URL.
    
    Returns:
    
    true, if source is readable
  - composeDataRaster
```
public static DataRaster composeDataRaster(org.gdal.gdal.Dataset ds,
                                           AVList params)
                                    throws java.lang.IllegalArgumentException,
                                           WWRuntimeException
```
    Throws:
    
    java.lang.IllegalArgumentException
    
    WWRuntimeException
  - composeImageDataRaster
```
protected static DataRaster composeImageDataRaster(org.gdal.gdal.Dataset ds,
                                                   AVList params)
                                            throws java.lang.IllegalArgumentException,
                                                   java.lang.SecurityException,
                                                   WWRuntimeException
```
    Opens image or elevation file, returns as a BufferedImage (even for elevations)
    
    Parameters:
    
    ds - GDAL's Dataset object
    
    params - AVList of parameters
    
    Returns:
    
    DataRaster returns as a BufferedImage (even for elevations)
    
    Throws:
    
    java.lang.IllegalArgumentException - if file is null
    
    java.lang.SecurityException - if file could not be read
    
    WWRuntimeException - if GDAL library was not initialized
  - composeNonImageDataRaster
```
protected static DataRaster composeNonImageDataRaster(org.gdal.gdal.Dataset ds,
                                                      AVList params)
                                               throws java.lang.IllegalArgumentException,
                                                      WWRuntimeException
```
    The "composeDataRaster" method creates a ByteBufferRaster from an elevation (or non-image) Dataset.
    
    Parameters:
    
    ds - The GDAL dataset with data raster (expected only elevation raster); f or imagery rasters use composeImageDataRaster() method
    
    params - , The AVList with properties (usually used to force projection info or sector)
    
    Returns:
    
    ByteBufferRaster as DataRaster
    
    Throws:
    
    java.lang.IllegalArgumentException - if raster parameters (height, width, sector, etc) are invalid
    
    WWRuntimeException - when invalid raster detected (like attempt to use the method for imagery raster)
  - convertStringToDouble
```
protected static java.lang.Double convertStringToDouble(java.lang.String s)
```
  - createGeographicSRS
```
public static org.gdal.osr.SpatialReference createGeographicSRS()
                                                         throws WWRuntimeException
```
    Throws:
    
    WWRuntimeException
  - detectVoidsAndMakeThemTransparent
```
protected static java.awt.image.BufferedImage detectVoidsAndMakeThemTransparent(java.awt.image.BufferedImage sourceImage)
```
    Attempts to detect if there are any black|white|gray voids (also called black skirts) i n the image raster caused by inaccurate clipping. The algorithm checks each corner of the image and if it detects black|white|gray pixel, uses a scanline version of flood fill algorithm to make the area transparent. See more http://en.wikipedia.org/wiki/Flood_fill#Scanline_fill
    
    Parameters:
    
    sourceImage - a source image raster
    
    Returns:
    
    BufferedImage with voids (if detected) filled with a transparent pixel values
  - extractBandOrder
```
public static int[] extractBandOrder(org.gdal.gdal.Dataset ds,
                                     AVList params)
                              throws java.lang.IllegalArgumentException,
                                     WWRuntimeException
```
    Throws:
    
    java.lang.IllegalArgumentException
    
    WWRuntimeException
  - extractImageMask
```
protected static java.nio.IntBuffer extractImageMask(AVList params)
```
  - extractMinMaxSampleValues
```
protected static void extractMinMaxSampleValues(org.gdal.gdal.Dataset ds,
                                                org.gdal.gdal.Band band,
                                                AVList params)
```
  - extractRasterParameters
```
public static AVList extractRasterParameters(org.gdal.gdal.Dataset ds)
                                      throws java.lang.IllegalArgumentException,
                                             WWRuntimeException
```
    Throws:
    
    java.lang.IllegalArgumentException
    
    WWRuntimeException
  - extractRasterParameters
```
public static AVList extractRasterParameters(org.gdal.gdal.Dataset ds,
                                             AVList params,
                                             boolean quickReadingMode)
                                      throws java.lang.IllegalArgumentException,
                                             WWRuntimeException
```
    Extracts raster parameters to an AVList
    
    Parameters:
    
    ds - A GDAL dataset
    
    params - AVList to hold retrieved metadata, if null, a new instance will be created and returned as a return value
    
    quickReadingMode - if quick reading mode is enabled GDAL will not spend much time on heavy calculations, like for example calculating Min/Max for entire elevation raster
    
    Returns:
    
    AVList with retrieved metadata
    
    Throws:
    
    java.lang.IllegalArgumentException - when the passed dataset is null pr emtpy, or any of the dimension is 0
    
    WWRuntimeException - if GDAL is not available, or a dataset contains no bands
    The extractRasterParameters() sets next key/value pairs:
    AVKey.WIDTH - the maximum width of the image
    AVKey.HEIGHT - the maximum height of the image
    AVKey.COORDINATE_SYSTEM - one of the next values: AVKey.COORDINATE_SYSTEM_SCREEN AVKey.COORDINATE_SYSTEM_GEOGRAPHIC AVKey.COORDINATE_SYSTEM_PROJECTED
    AVKey.SECTOR - in case of Geographic CS, contains a regular Geographic Sector defined by lat/lon coordinates of corners in case of Projected CS, contains a bounding box of the area
    AVKey.COORDINATE_SYSTEM_NAME
    AVKey.PIXEL_WIDTH (Double) pixel size, UTM images usually specify 1 (1 meter); if missing and Geographic Coordinate System is specified will be calculated as LongitudeDelta/WIDTH
    AVKey.PIXEL_HEIGHT (Double) pixel size, UTM images usually specify 1 (1 meter); if missing and Geographic Coordinate System is specified will be calculated as LatitudeDelta/HEIGHT
    AVKey.ORIGIN (LatLon) specifies coordinate of the image's origin (one of the corners, or center) If missing, upper left corner will be set as origin
    AVKey.DATE_TIME (0 terminated String, length == 20) if missing, current date & time will be used
    AVKey.PIXEL_FORMAT required (valid values: AVKey.ELEVATION | AVKey.IMAGE } specifies weather it is a digital elevation model or image
    AVKey.IMAGE_COLOR_FORMAT required if AVKey.PIXEL_FORMAT is AVKey.IMAGE (valid values: AVKey.COLOR and AVKey.MONOCHROME)
    AVKey.DATA_TYPE required ( valid values: AVKey.INT16, and AVKey.FLOAT32 )
    AVKey.VERSION optional, if missing a default will be used "NASA World Wind"
    AVKey.DISPLAY_NAME, (String) optional, specifies a name of the document/image
    AVKey.DESCRIPTION (String) optional, for any kind of descriptions
    AVKey.MISSING_DATA_SIGNAL optional, set the AVKey.MISSING_DATA_SIGNAL ONLY if you know for sure that the specified value actually represents void (NODATA) areas. Elevation data usually has "-32767" (like DTED), or "-32768" like SRTM, but some has "0" (mostly images) and "-9999" like NED. Note! Setting "-9999" is very ambiguos because -9999 for elevation is valid value;
    AVKey.MISSING_DATA_REPLACEMENT (String type forced by spec) Most images have "NODATA" as "0", elevations have as "-9999", or "-32768" (sometimes "-32767")
    AVKey.COORDINATE_SYSTEM required, valid values AVKey.COORDINATE_SYSTEM_GEOGRAPHIC or AVKey.COORDINATE_SYSTEM_PROJECTED
    AVKey.COORDINATE_SYSTEM_NAME Optional, A name of the Coordinates System as a String
    AVKey.PROJECTION_EPSG_CODE Required; Integer; EPSG code or Projection Code If CS is Geodetic and EPSG code is not specified, a default WGS84 (4326) will be used
    AVKey.PROJECTION_DATUM Optional, AVKey.PROJECTION_DESC Optional, AVKey.PROJECTION_NAME Optional, AVKey.PROJECTION_UNITS Optional,
    AVKey.ELEVATION_UNIT Required, if AVKey.PIXEL_FORMAT = AVKey.ELEVATION, value: AVKey.UNIT_FOOT or AVKey.UNIT_METER (default, if not specified)
    AVKey.RASTER_PIXEL, optional, values: AVKey.RASTER_PIXEL_IS_AREA or AVKey.RASTER_PIXEL_IS_POINT if not specified, default for images is RASTER_PIXEL_IS_AREA, and AVKey.RASTER_PIXEL_IS_POINT for elevations
  - findGdalDataFolder
```
protected static java.lang.String findGdalDataFolder(java.lang.String dir)
```
  - findGdalPlugins
```
protected static java.lang.String findGdalPlugins(java.lang.String dir)
```
  - getCurrentDirectory
```
protected static java.lang.String getCurrentDirectory()
```
  - getErrorMessage
```
public static java.lang.String getErrorMessage()
```
    Returns:
    
    returns an error string, if no errors returns null
  - getLatLonForRasterPoint
```
protected static LatLon getLatLonForRasterPoint(double[] gt,
                                                int x,
                                                int y,
                                                org.gdal.osr.CoordinateTransformation ct)
```
  - listAllRegisteredDrivers
```
protected static void listAllRegisteredDrivers()
```
  - open
```
public static org.gdal.gdal.Dataset open(java.lang.Object source)
                                  throws java.io.FileNotFoundException,
                                         java.lang.IllegalArgumentException,
                                         java.lang.SecurityException,
                                         WWRuntimeException
```
    Opens image or elevation file, returns a DataSet object
    
    Parameters:
    
    source - the location of the local file, expressed as either a String path, a File, or a file URL.
    
    Returns:
    
    returns a Dataset object
    
    Throws:
    
    java.io.FileNotFoundException - if file not found
    
    java.lang.IllegalArgumentException - if file is null
    
    java.lang.SecurityException - if file could not be read
    
    WWRuntimeException - if GDAL library was not initialized
  - open
```
public static org.gdal.gdal.Dataset open(java.lang.Object source,
                                         boolean isSilentMode)
                                  throws java.io.FileNotFoundException,
                                         java.lang.IllegalArgumentException,
                                         java.lang.SecurityException,
                                         WWRuntimeException
```
    Opens image or elevation file, returns a DataSet object
    
    Parameters:
    
    source - the location of the local file, expressed as either a String path, a File, or a file URL.
    
    isSilentMode - specifies a silent mode of reading file (usually needed for canRead() and readMetadata())
    
    Returns:
    
    returns a Dataset object
    
    Throws:
    
    java.io.FileNotFoundException - if file not found
    
    java.lang.IllegalArgumentException - if file is null
    
    java.lang.SecurityException - if file could not be read
    
    WWRuntimeException - if GDAL library was not initialized
  - scanFill
```
protected static void scanFill(java.awt.image.BufferedImage sourceImage)
```
  - setNoDataValue
```
protected static boolean setNoDataValue(org.gdal.gdal.Band band,
                                        java.lang.Double nodata)
```
  - verticalFlip
```
protected static java.awt.image.BufferedImage verticalFlip(java.awt.image.BufferedImage img)
```
    Flips image raster vertically
    
    Parameters:
    
    img - A source raster as a BufferedImage
    
    Returns:
    
    A vertically flipped image raster as a BufferedImage

Class GDALUtils

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ALPHA_MASK

ALPHA_OPAQUE

ALPHA_TRANSPARENT

GDAL_DATA_PATH

GDAL_DRIVER_PATH

gdalIsAvailable

JAVA_LIBRARY_PATH

Constructor Detail

GDALUtils

Method Detail

applyImageMask

applyImageMask

applyImageMask

buildPathString

calcGetGeoTransform

canOpen

composeDataRaster

composeImageDataRaster

composeNonImageDataRaster

convertStringToDouble

createGeographicSRS

detectVoidsAndMakeThemTransparent

extractBandOrder

extractImageMask

extractMinMaxSampleValues

extractRasterParameters

extractRasterParameters

findGdalDataFolder

findGdalPlugins

getCurrentDirectory

getErrorMessage

getLatLonForRasterPoint

listAllRegisteredDrivers

open

open

scanFill

setNoDataValue

verticalFlip