Package org.apache.commons.imaging.formats.gif

Class GifImageParser

    • Field Detail

      • LOGGER

        private static final java.util.logging.Logger LOGGER

      • DEFAULT_EXTENSION

        private static final java.lang.String DEFAULT_EXTENSION

      • ACCEPTED_EXTENSIONS

        private static final java.lang.String[] ACCEPTED_EXTENSIONS

      • GIF_HEADER_SIGNATURE

        private static final byte[] GIF_HEADER_SIGNATURE

      • GRAPHIC_CONTROL_EXTENSION

        private static final int GRAPHIC_CONTROL_EXTENSION
        See Also:
        Constant Field Values

      • APPLICATION_EXTENSION_LABEL

        private static final int APPLICATION_EXTENSION_LABEL
        See Also:
        Constant Field Values

      • LOCAL_COLOR_TABLE_FLAG_MASK

        private static final int LOCAL_COLOR_TABLE_FLAG_MASK
        See Also:
        Constant Field Values

      • XMP_APPLICATION_ID_AND_AUTH_CODE

        private static final byte[] XMP_APPLICATION_ID_AND_AUTH_CODE

    • Constructor Detail

      • GifImageParser

        public GifImageParser()
        Constructs a new instance with the little-endian byte order.

    • Method Detail

      • convertColorTableSize

        private int convertColorTableSize​(int tableSize)

      • dumpImageFile

        public boolean dumpImageFile​(java.io.PrintWriter pw,
                             ByteSource byteSource)
                      throws ImagingException,
                             java.io.IOException
        Description copied from class: AbstractImageParser
        Writes the ImageInfo and format-specific information for the image content of the specified byte source to a PrintWriter
        Overrides:
        dumpImageFile in class AbstractImageParser<GifImagingParameters>
        Parameters:
        pw - print writer used for writing the ImageInfo
        byteSource - A valid byte source.
        Returns:
        A valid PrintWriter.
        Throws:
        ImagingException - In the event that the specified content does not conform to the format of the specific parser implementation.
        java.io.IOException - In the event of unsuccessful read or access operation.

      • findBlock

        private GifBlock findBlock​(java.util.List<GifBlock> blocks,
                           int code)

      • getAllBufferedImages

        public java.util.List<java.awt.image.BufferedImage> getAllBufferedImages​(ByteSource byteSource)
                                                                  throws ImagingException,
                                                                         java.io.IOException
        Description copied from class: AbstractImageParser
        Gets all images specified by the byte source (some formats may include multiple images within a single data source).
        Overrides:
        getAllBufferedImages in class AbstractImageParser<GifImagingParameters>
        Parameters:
        byteSource - A valid instance of ByteSource.
        Returns:
        A valid (potentially empty) list of BufferedImage objects.
        Throws:
        ImagingException - In the event that the specified content does not conform to the format of the specific parser implementation.
        java.io.IOException - In the event of unsuccessful read or access operation.

      • getBufferedImage

        public java.awt.image.BufferedImage getBufferedImage​(ByteSource byteSource,
                                                     GifImagingParameters params)
                                              throws ImagingException,
                                                     java.io.IOException
        Description copied from class: AbstractImageParser
        Gets a buffered image specified by the byte source (for sources that specify multiple images, choice of which image is returned is implementation dependent).
        Specified by:
        getBufferedImage in class AbstractImageParser<GifImagingParameters>
        Parameters:
        byteSource - A valid instance of ByteSource
        params - Optional instructions for special-handling or interpretation of the input data (null objects are permitted and must be supported by implementations).
        Returns:
        A valid instance of BufferedImage.
        Throws:
        ImagingException - In the event that the specified content does not conform to the format of the specific parser implementation.
        java.io.IOException - In the event of unsuccessful read or access operation.

      • getComments

        private java.util.List<java.lang.String> getComments​(java.util.List<GifBlock> blocks)
                                              throws java.io.IOException
        Throws:
        java.io.IOException

      • getDefaultExtension

        public java.lang.String getDefaultExtension()
        Description copied from class: AbstractImageParser
        Gets the default extension for the format specified by an implementation of ImageParser. Some parsers can support more than one extension (i.e. .JPEG, .JPG; .TIF, .TIFF, etc.).
        Specified by:
        getDefaultExtension in class AbstractImageParser<GifImagingParameters>
        Returns:
        A valid string.

      • getIccProfileBytes

        public byte[] getIccProfileBytes​(ByteSource byteSource,
                                 GifImagingParameters params)
                          throws ImagingException,
                                 java.io.IOException
        Description copied from class: AbstractImageParser
        Gets an array of bytes describing the International Color Consortium (ICC) specification for the color space of the image contained in the input byteSource. Not all formats support ICC profiles.
        Specified by:
        getIccProfileBytes in class AbstractImageParser<GifImagingParameters>
        Parameters:
        byteSource - A valid ByteSource.
        params - Optional instructions for special-handling or interpretation of the input data.
        Returns:
        If available, a valid array of bytes; otherwise, a null
        Throws:
        ImagingException - In the event that the specified content does not conform to the format of the specific parser implementation.
        java.io.IOException - In the event of unsuccessful read or access operation.

      • getImageInfo

        public ImageInfo getImageInfo​(ByteSource byteSource,
                              GifImagingParameters params)
                       throws ImagingException,
                              java.io.IOException
        Description copied from class: AbstractImageParser
        Gets image information from the specified ByteSource. Format-specific ImageParser implementations are expected to return a valid ImageInfo object or to throw an ImageReadException if unable to process the specified data.

        The params argument provides a mechanism for individual implementations to pass optional information into the parser. Not all formats will require this capability. Because the base class may call this method with a null params argument, implementations should always include logic for ignoring null input.

        Specified by:
        getImageInfo in class AbstractImageParser<GifImagingParameters>
        Parameters:
        byteSource - A valid ByteSource object
        params - Optional instructions for special-handling or interpretation of the input data (null objects are permitted and must be supported by implementations).
        Returns:
        A valid image information object describing the content extracted from the specified data.
        Throws:
        ImagingException - In the event that the specified content does not conform to the format of the specific parser implementation.
        java.io.IOException - In the event of unsuccessful data access operation.

      • getImageSize

        public java.awt.Dimension getImageSize​(ByteSource byteSource,
                                       GifImagingParameters params)
                                throws ImagingException,
                                       java.io.IOException
        Description copied from class: AbstractImageParser
        Gets the size of the image described by the specified ByteSource.
        Specified by:
        getImageSize in class AbstractImageParser<GifImagingParameters>
        Parameters:
        byteSource - A valid reference to a ByteSource.
        params - Optional instructions for special-handling or interpretation of the input data.
        Returns:
        A valid instance of Dimension.
        Throws:
        ImagingException - In the event that the specified content does not conform to the format of the specific parser implementation.
        java.io.IOException - In the event of unsuccessful read or access operation.

      • getMetadata

        public ImageMetadata getMetadata​(ByteSource byteSource,
                                 GifImagingParameters params)
                          throws ImagingException,
                                 java.io.IOException
        Description copied from class: AbstractImageParser
        Gets image metadata from the specified byte source. Format-specific ImageParser implementations are expected to return a valid IImageMetadata object or to throw an ImageReadException if unable to process the specified byte source.

        The params argument provides a mechanism for individual implementations to pass optional information into the parser. Not all formats will require this capability. Because the base class may call this method with a null params argument, implementations should always include logic for ignoring null input.

        Specified by:
        getMetadata in class AbstractImageParser<GifImagingParameters>
        Parameters:
        byteSource - A valid byte source.
        params - Optional instructions for special-handling or interpretation of the input data (null objects are permitted and must be supported by implementations).
        Returns:
        A valid, potentially subject-matter-specific implementation of the IImageMetadata interface describing the content extracted from the source content.
        Throws:
        ImagingException - In the event that the ByteSource content does not conform to the format of the specific parser implementation.
        java.io.IOException - In the event of unsuccessful data read operation.

      • getXmpXml

        public java.lang.String getXmpXml​(ByteSource byteSource,
                                  XmpImagingParameters<GifImagingParameters> params)
                           throws ImagingException,
                                  java.io.IOException
        Extracts embedded XML metadata as XML string.

        Specified by:
        getXmpXml in interface XmpEmbeddable<GifImagingParameters>
        Parameters:
        byteSource - File containing image data.
        params - Map of optional parameters, defined in ImagingConstants.
        Returns:
        Xmp Xml as String, if present. Otherwise, returns null.
        Throws:
        ImagingException - In the event that the specified content does not conform to the format of the specific parser implementation.
        java.io.IOException - In the event of unsuccessful read or access operation.

      • readColorTable

        private byte[] readColorTable​(java.io.InputStream is,
                              int tableSize)
                       throws java.io.IOException
        Throws:
        java.io.IOException

      • readGenericGifBlock

        private GenericGifBlock readGenericGifBlock​(java.io.InputStream is,
                                            int code)
                                     throws java.io.IOException
        Throws:
        java.io.IOException

      • readGenericGifBlock

        private GenericGifBlock readGenericGifBlock​(java.io.InputStream is,
                                            int code,
                                            byte[] first)
                                     throws java.io.IOException
        Throws:
        java.io.IOException

      • readGraphicControlExtension

        private GraphicControlExtension readGraphicControlExtension​(int code,
                                                            java.io.InputStream is)
                                                     throws java.io.IOException
        Throws:
        java.io.IOException

      • readSubBlock

        private byte[] readSubBlock​(java.io.InputStream is)
                     throws java.io.IOException
        Throws:
        java.io.IOException

      • simplePow

        private int simplePow​(int base,
                      int power)

      • writeAsSubBlocks

        private void writeAsSubBlocks​(byte[] bytes,
                              java.io.OutputStream os)
                       throws java.io.IOException
        Throws:
        java.io.IOException

      • writeImage

        public void writeImage​(java.awt.image.BufferedImage src,
                       java.io.OutputStream os,
                       GifImagingParameters params)
                throws ImagingException,
                       java.io.IOException
        Description copied from class: AbstractImageParser
        Writes the content of a BufferedImage to the specified output stream.

        The params argument provides a mechanism for individual implementations to pass optional information into the parser. Not all formats will support this capability. Currently, some of the parsers do not check for null arguments.

        Overrides:
        writeImage in class AbstractImageParser<GifImagingParameters>
        Parameters:
        src - An image giving the source content for output
        os - A valid output stream for storing the formatted image
        params - optional parameters, defining format-specific instructions for output (such as selections for data compression, color models, etc.)
        Throws:
        ImagingException - In the event that the output format cannot handle the input image or invalid params are specified.
        java.io.IOException - In the event of an write error from the output stream.