Package org.geotools.image.io

Class ImageIOExt

Object
ImageIOExt
public class ImageIOExt extends Object
Provides an alternative source of image input and output streams that uses optimized behavior.

Currently implemented optimizations:

Since:
2.7.2
Author:
Andrea Aime - GeoSolutions

  • Constructor Details

    • ImageIOExt

      public ImageIOExt()

  • Method Details

    • createImageOutputStream

      public static ImageOutputStream createImageOutputStream(RenderedImage image, Object destination) throws IOException
      Builds a ImageOutputStream writing to destination, based on logic that involves the image size
      Parameters:
      image - the image to be written on the destination (can be null)
      destination - the destination
      Throws:
      IOException

    • createImageInputStream

      public static ImageInputStream createImageInputStream(Object input) throws IOException
      Returns a ImageOutputStream suitable for writing on the specified input
      Throws:
      IOException

    • getCacheDirectory

      public static File getCacheDirectory()
      Returns the cache directory used by ImageIOExt, either the manually configured one, or the result of calling ImageIO.getCacheDirectory()

    • setCacheDirectory

      public static void setCacheDirectory(File cache)
      Sets the directory where cache files are to be created. If set to null (the default value) ImageIO.getCacheDirectory() will be used as the value
      Parameters:
      cache - a File specifying a directory.

    • getFilesystemThreshold

      public static Long getFilesystemThreshold()
      The threshold at which the class will flip from MemoryCacheImageOutputStream to FileCacheImageOutputStream. If the in memory, uncompressed image size is lower than the threshold a MemoryCacheImageOutputStream will be returned, otherwise a FileCacheImageOutputStream will be used instead

    • setFilesystemThreshold

      public static void setFilesystemThreshold(Long filesystemThreshold)
      Sets the memory/file usage threshold (or null to have the code fall back on ImageIO behavior)
      See Also:

    • allowNativeCodec

      public static <T extends ImageReaderWriterSpi> void allowNativeCodec(String format, Class<T> category, boolean allowed)
      Allows or disallows native acceleration for the specified image format. By default, the image I/O extension for JAI provides native acceleration for PNG and JPEG. Unfortunatly, those native codec has bug in their 1.0 version. Invoking this method will force the use of standard codec provided in J2SE 1.4.

      Implementation note: the current implementation assume that JAI codec class name start with "CLib". It work for Sun's 1.0 implementation, but may change in future versions. If this method doesn't recognize the class name, it does nothing.

      Parameters:
      format - The format name (e.g. "png").
      category - ImageReaderSpi.class to set the reader, or ImageWriterSpi.class to set the writer.
      allowed - false to disallow native acceleration.

    • getImageInputStreamSPI

      public static final ImageInputStreamSpi getImageInputStreamSPI(Object input)
      Get a proper ImageInputStreamSpi instance for the provided Object input without trying to create an ImageInputStream.
      See Also:

    • getImageInputStreamSPI

      public static final ImageInputStreamSpi getImageInputStreamSPI(Object input, boolean streamCreationCheck)
      Get a proper ImageInputStreamSpi instance for the provided Object input.
      Parameters:
      input - the input object for which we need to find a proper ImageInputStreamSpi instance
      streamCreationCheck - if true, when a proper ImageInputStreamSpi have been found for the provided input, use it to try creating an ImageInputStream on top of the input.
      Returns:
      an ImageInputStreamSpi instance.

    • isCLibAvailable

      public static boolean isCLibAvailable()
      Tells me whether or not the native libraries for JAI/ImageIO are active or not.
      Returns:
      false in case the JAI/ImageIO native libs are not in the path, true otherwise.

    • getImageioReader

      public static ImageReader getImageioReader(ImageInputStream inStream)
      Look for an ImageReader instance that is able to read the provided ImageInputStream, which must be non null.

      In case no reader is found, null is returned.

      Parameters:
      inStream - an instance of ImageInputStream for which we need to find a suitable ImageReader.
      Returns:
      a suitable instance of ImageReader or null if one cannot be found.

    • read

      public static RenderedImage read(Object input) throws IOException
      Reads an image from the given input, working around some JDK reader issues. At the time of writing, this applies a work around for PNGs with RGB (no alpha) and a transparent color configured in the header, that the JDK reader cannot handle.
      Parameters:
      input - A non null image source, like a File, URL, or InputStream
      Returns:
      A image
      Throws:
      IOException

    • readBufferedImage

      public static BufferedImage readBufferedImage(Object input) throws IOException
      Same as read(Object) but ensures the result is a BufferedImage, eventually transforming it if needs be. Callers that can deal with RenderedImage should use the other method for efficiency sake.
      Returns:
      A image
      Throws:
      IOException