Package org.apache.commons.imaging.formats.tiff.itu_t4

Class T4AndT6Compression

  • public final class T4AndT6Compression
extends java.lang.Object

    • Constructor Detail

      • T4AndT6Compression

        private T4AndT6Compression()

    • Method Detail

      • changingElementAt

        private static int changingElementAt​(int[] line,
                                     int position)

      • compressModifiedHuffman

        public static byte[] compressModifiedHuffman​(byte[] uncompressed,
                                             int width,
                                             int height)
                                      throws ImagingException
        Compressed with the "Modified Huffman" encoding of section 10 in the TIFF6 specification. No EOLs, no RTC, rows are padded to end on a byte boundary.
        Parameters:
        uncompressed - uncompressed byte data
        width - image width
        height - image height
        Returns:
        the compressed data
        Throws:
        ImagingException - if it fails to write the compressed data

      • compressT

        private static int compressT​(int a0,
                             int a1,
                             int b1,
                             BitArrayOutputStream outputStream,
                             int codingA0Color,
                             int[] codingLine)

      • compressT4_1D

        public static byte[] compressT4_1D​(byte[] uncompressed,
                                   int width,
                                   int height,
                                   boolean hasFill)
                            throws ImagingException
        Throws:
        ImagingException

      • compressT4_2D

        public static byte[] compressT4_2D​(byte[] uncompressed,
                                   int width,
                                   int height,
                                   boolean hasFill,
                                   int parameterK)
                            throws ImagingException
        Throws:
        ImagingException

      • decompressModifiedHuffman

        public static byte[] decompressModifiedHuffman​(byte[] compressed,
                                               int width,
                                               int height)
                                        throws ImagingException
        Decompresses the "Modified Huffman" encoding of section 10 in the TIFF6 specification. No EOLs, no RTC, rows are padded to end on a byte boundary.
        Parameters:
        compressed - compressed byte data
        width - image width
        height - image height
        Returns:
        the compressed data
        Throws:
        ImagingException - if it fails to read the compressed data

      • decompressT4_1D

        public static byte[] decompressT4_1D​(byte[] compressed,
                                     int width,
                                     int height,
                                     boolean hasFill)
                              throws ImagingException
        Decompresses T.4 1D encoded data. EOL at the beginning and after each row, can be preceded by fill bits to fit on a byte boundary, no RTC.
        Parameters:
        compressed - compressed byte data
        width - image width
        height - image height
        hasFill - used to check the end of line
        Returns:
        the decompressed data
        Throws:
        ImagingException - if it fails to read the compressed data

      • decompressT4_2D

        public static byte[] decompressT4_2D​(byte[] compressed,
                                     int width,
                                     int height,
                                     boolean hasFill)
                              throws ImagingException
        Decompressed T.4 2D encoded data. EOL at the beginning and after each row, can be preceded by fill bits to fit on a byte boundary, and is succeeded by a tag bit determining whether the next line is encoded using 1D or 2D. No RTC.
        Parameters:
        compressed - compressed byte data
        width - image width
        height - image height
        hasFill - used to check the end of line
        Returns:
        the decompressed data
        Throws:
        ImagingException - if it fails to read the compressed data

      • decompressT6

        public static byte[] decompressT6​(byte[] compressed,
                                  int width,
                                  int height)
                           throws ImagingException
        Decompress T.6 encoded data. No EOLs, except for 2 consecutive ones at the end (the EOFB, end of fax block). No RTC. No fill bits anywhere. All data is 2D encoded.
        Parameters:
        compressed - compressed byte data
        width - image width
        height - image height
        Returns:
        the decompressed data
        Throws:
        ImagingException - if it fails to read the compressed data

      • fillRange

        private static void fillRange​(BitArrayOutputStream outputStream,
                              int[] referenceRow,
                              int a0,
                              int end,
                              int color)

      • nextChangingElement

        private static int nextChangingElement​(int[] line,
                                       int currentColour,
                                       int start)

      • writeRunLength

        private static void writeRunLength​(BitArrayOutputStream bitStream,
                                   int runLength,
                                   int color)