jpegencoder.java

基于JPEG图像的数字密写方法 F5算法的JAVA程序

        quantum_chrominance[37]=99;
        quantum_chrominance[38]=99;
        quantum_chrominance[39]=99;
        quantum_chrominance[40]=99;
        quantum_chrominance[41]=99;
        quantum_chrominance[42]=99;
        quantum_chrominance[43]=99;
        quantum_chrominance[44]=99;
        quantum_chrominance[45]=99;
        quantum_chrominance[46]=99;
        quantum_chrominance[47]=99;
        quantum_chrominance[48]=99;
        quantum_chrominance[49]=99;
        quantum_chrominance[50]=99;
        quantum_chrominance[51]=99;
        quantum_chrominance[52]=99;
        quantum_chrominance[53]=99;
        quantum_chrominance[54]=99;
        quantum_chrominance[55]=99;
        quantum_chrominance[56]=99;
        quantum_chrominance[57]=99;
        quantum_chrominance[58]=99;
        quantum_chrominance[59]=99;
        quantum_chrominance[60]=99;
        quantum_chrominance[61]=99;
        quantum_chrominance[62]=99;
        quantum_chrominance[63]=99;

        for (j = 0; j < 64; j++)
        {
                temp = (quantum_chrominance[j] * Quality + 50) / 100;
                if ( temp <= 0) temp = 1;
                if (temp >= 255) temp = 255;
                quantum_chrominance[j] = temp;
        }
        index = 0;
        for (i = 0; i < 8; i++) {
                for (j = 0; j < 8; j++) {
// The divisors for the LL&M method (the slow integer method used in
// jpeg 6a library).  This method is currently (04/04/98) incompletely
// implemented.
//                        DivisorsChrominance[index] = ((double) quantum_chrominance[index]) << 3;
// The divisors for the AAN method (the float method used in jpeg 6a library.
                        DivisorsChrominance[index] = (double) ((double)1.0/((double) quantum_chrominance[index] * AANscaleFactor[i] * AANscaleFactor[j] * (double)8.0));
                        index++;
                }
        }

// quantum and Divisors are objects used to hold the appropriate matices

        quantum[0] = quantum_luminance;
        Divisors[0] = DivisorsLuminance;
        quantum[1] = quantum_chrominance;
        Divisors[1] = DivisorsChrominance;


    }

    /*
     * This method preforms forward DCT on a block of image data using
     * the literal method specified for a 2-D Discrete Cosine Transform.
     * It is included as a curiosity and can give you an idea of the
     * difference in the compression result (the resulting image quality)
     * by comparing its output to the output of the AAN method below.
     * It is ridiculously inefficient.
     */

// For now the final output is unusable.  The associated quantization step
// needs some tweaking.  If you get this part working, please let me know.

    public double[][] forwardDCTExtreme(float input[][])
    {
        double output[][] = new double[N][N];
        double tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
        double tmp10, tmp11, tmp12, tmp13;
        double z1, z2, z3, z4, z5, z11, z13;
        int i;
        int j;
        int v, u, x, y;
        for (v = 0; v < 8; v++) {
                for (u = 0; u < 8; u++) {
                        for (x = 0; x < 8; x++) {
                                for (y = 0; y < 8; y++) {
                                        output[v][u] += ((double)input[x][y])*Math.cos(((double)(2*x + 1)*(double)u*Math.PI)/(double)16)*Math.cos(((double)(2*y + 1)*(double)v*Math.PI)/(double)16);
                                }
                        }
                        output[v][u] *= (double)(0.25)*((u == 0) ? ((double)1.0/Math.sqrt(2)) : (double) 1.0)*((v == 0) ? ((double)1.0/Math.sqrt(2)) : (double) 1.0);
                }
        }
        return output;
    }
                                                                

    /*
     * This method preforms a DCT on a block of image data using the AAN
     * method as implemented in the IJG Jpeg-6a library.
     */
    public double[][] forwardDCT(float input[][])
    {
        double output[][] = new double[N][N];
        double tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
        double tmp10, tmp11, tmp12, tmp13;
        double z1, z2, z3, z4, z5, z11, z13;
        int i;
        int j;

// Subtracts 128 from the input values
        for (i = 0; i < 8; i++) {
                for(j = 0; j < 8; j++) {
                        output[i][j] = ((double)input[i][j] - (double)128.0);
//                        input[i][j] -= 128;

                }
        }

        for (i = 0; i < 8; i++) {
                tmp0 = output[i][0] + output[i][7];
                tmp7 = output[i][0] - output[i][7];
                tmp1 = output[i][1] + output[i][6];
                tmp6 = output[i][1] - output[i][6];
                tmp2 = output[i][2] + output[i][5];
                tmp5 = output[i][2] - output[i][5];
                tmp3 = output[i][3] + output[i][4];
                tmp4 = output[i][3] - output[i][4];

                tmp10 = tmp0 + tmp3;
                tmp13 = tmp0 - tmp3;
                tmp11 = tmp1 + tmp2;
                tmp12 = tmp1 - tmp2;

                output[i][0] = tmp10 + tmp11;
                output[i][4] = tmp10 - tmp11;

                z1 = (tmp12 + tmp13) * (double) 0.707106781;
                output[i][2] = tmp13 + z1;
                output[i][6] = tmp13 - z1;

                tmp10 = tmp4 + tmp5;
                tmp11 = tmp5 + tmp6;
                tmp12 = tmp6 + tmp7;

                z5 = (tmp10 - tmp12) * (double) 0.382683433;
                z2 = ((double) 0.541196100) * tmp10 + z5;
                z4 = ((double) 1.306562965) * tmp12 + z5;
                z3 = tmp11 * ((double) 0.707106781);

                z11 = tmp7 + z3;
                z13 = tmp7 - z3;

                output[i][5] = z13 + z2;
                output[i][3] = z13 - z2;
                output[i][1] = z11 + z4;
                output[i][7] = z11 - z4;
        }

        for (i = 0; i < 8; i++) {
                tmp0 = output[0][i] + output[7][i];
                tmp7 = output[0][i] - output[7][i];
                tmp1 = output[1][i] + output[6][i];
                tmp6 = output[1][i] - output[6][i];
                tmp2 = output[2][i] + output[5][i];
                tmp5 = output[2][i] - output[5][i];
                tmp3 = output[3][i] + output[4][i];
                tmp4 = output[3][i] - output[4][i];

                tmp10 = tmp0 + tmp3;
                tmp13 = tmp0 - tmp3;
                tmp11 = tmp1 + tmp2;
                tmp12 = tmp1 - tmp2;

                output[0][i] = tmp10 + tmp11;
                output[4][i] = tmp10 - tmp11;

                z1 = (tmp12 + tmp13) * (double) 0.707106781;
                output[2][i] = tmp13 + z1;
                output[6][i] = tmp13 - z1;

                tmp10 = tmp4 + tmp5;
                tmp11 = tmp5 + tmp6;
                tmp12 = tmp6 + tmp7;

                z5 = (tmp10 - tmp12) * (double) 0.382683433;
                z2 = ((double) 0.541196100) * tmp10 + z5;
                z4 = ((double) 1.306562965) * tmp12 + z5;
                z3 = tmp11 * ((double) 0.707106781);

                z11 = tmp7 + z3;
                z13 = tmp7 - z3;

                output[5][i] = z13 + z2;
                output[3][i] = z13 - z2;
                output[1][i] = z11 + z4;
                output[7][i] = z11 - z4;
        }

        return output;
    }

    /*
    * This method quantitizes data and rounds it to the nearest integer.
    */
    public int[] quantizeBlock(double inputData[][], int code)
    {
        int outputData[] = new int[N*N];
        int i, j;
        int index;
        index = 0;
        for (i = 0; i < 8; i++) {
                for (j = 0; j < 8; j++) {
// The second line results in significantly better compression.
                        outputData[index] = (int)(Math.round(inputData[i][j] * (((double[]) (Divisors[code]))[index])));
//                        outputData[index] = (int)(((inputData[i][j] * (((double[]) (Divisors[code]))[index])) + 16384.5) -16384);
                        index++;
                }
        }

        return outputData;
    }

    /*
    * This is the method for quantizing a block DCT'ed with forwardDCTExtreme
    * This method quantitizes data and rounds it to the nearest integer.
    */
    public int[] quantizeBlockExtreme(double inputData[][], int code)
    {
        int outputData[] = new int[N*N];
        int i, j;
        int index;
        index = 0;
        for (i = 0; i < 8; i++) {
                for (j = 0; j < 8; j++) {
                        outputData[index] = (int)(Math.round(inputData[i][j] / (double)(((int[]) (quantum[code]))[index])));
                        index++;
                }
        }

        return outputData;
    }
}

// This class was modified by James R. Weeks on 3/27/98.
// It now incorporates Huffman table derivation as in the C jpeg library
// from the IJG, Jpeg-6a.

class Huffman
{
    int bufferPutBits, bufferPutBuffer;    
    public int ImageHeight;
    public int ImageWidth;
    public int DC_matrix0[][];
    public int AC_matrix0[][];
    public int DC_matrix1[][];
    public int AC_matrix1[][];
    public Object DC_matrix[];
    public Object AC_matrix[];
    public int code;
    public int NumOfDCTables;
    public int NumOfACTables;
    public int[] bitsDCluminance = { 0x00, 0, 1, 5, 1, 1,1,1,1,1,0,0,0,0,0,0,0};
    public int[] valDCluminance = { 0,1,2,3,4,5,6,7,8,9,10,11 };
    public int[] bitsDCchrominance = { 0x01,0,3,1,1,1,1,1,1,1,1,1,0,0,0,0,0 };
    public int[] valDCchrominance = { 0,1,2,3,4,5,6,7,8,9,10,11 };
    public int[] bitsACluminance = {0x10,0,2,1,3,3,2,4,3,5,5,4,4,0,0,1,0x7d };
    public int[] valACluminance =
        { 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
          0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
          0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
          0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
          0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
          0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
          0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
          0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
          0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
          0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
          0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
          0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
          0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
          0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
          0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
          0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
          0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
          0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
          0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
          0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
          0xf9, 0xfa };
    public int[] bitsACchrominance = { 0x11,0,2,1,2,4,4,3,4,7,5,4,4,0,1,2,0x77 };;
    public int[] valACchrominance = 
        { 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
          0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
          0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
          0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
          0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,
          0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
          0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38, 
          0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 
          0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 
          0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 
          0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 
          0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 
          0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 
          0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 
          0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 
          0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 
          0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 
          0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 
          0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 
          0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
          0xf9, 0xfa };
    public Vector bits;
    public Vector val;

    /*
     * jpegNaturalOrder[i] is the natural-order position of the i'th element
     * of zigzag order.
     */
    public static int[] jpegNaturalOrder = {
          0,  1,  8, 16,  9,  2,  3, 10,
         17, 24, 32, 25, 18, 11,  4,  5,
         12, 19, 26, 33, 40, 48, 41, 34,
         27, 20, 13,  6,  7, 14, 21, 28,
         35, 42, 49, 56, 57, 50, 43, 36,
         29, 22, 15, 23, 30, 37, 44, 51,
         58, 59, 52, 45, 38, 31, 39, 46,
         53, 60, 61, 54, 47, 55, 62, 63,
        };
    /*
    * The Huffman class constructor
    */
        public Huffman(int Width,int Height)
	{

            bits = new Vector();
            bits.addElement(bitsDCluminance);
            bits.addElement(bitsACluminance);
            bits.addElement(bitsDCchrominance);
            bits.addElement(bitsACchrominance);
            val = new Vector();
            val.addElement(valDCluminance);
            val.addElement(valACluminance);
            val.addElement(valDCchrominance);
            val.addElement(valACchrominance);
            initHuf();
	    code=code;
            ImageWidth=Width;
            ImageHeight=Height;

	}

   /**
   * HuffmanBlockEncoder run length encodes and Huffman encodes the quantized
   * data.
   **/

        public void HuffmanBlockEncoder(BufferedOutputStream outStream, int zigzag[], int prec, int DCcode, int ACcode)
	{
        int temp, temp2, nbits, k, r, i;

        NumOfDCTables = 2;
        NumOfACTables = 2;

// The DC portion

        temp = temp2 = zigzag[0] - prec;
        if(temp < 0) {
                temp = -temp;
                temp2--;
        }
        nbits = 0;
        while (temp != 0) {
                nbits++;
                temp >>= 1;
        }
//        if (nbits > 11) nbits = 11;
        bufferIt(outStream, ((int[][])DC_matrix[DCcode])[nbits][0], ((int[][])DC_matrix[DCcode])[nbits][1]);
        // The arguments in bufferIt are code and size.
        if (nbits != 0) {
                bufferIt(outStream, temp2, nbits);
        }

// The AC portion

        r = 0;

        for (k = 1; k < 64; k++) {
                if ((temp = zigzag[jpegNaturalOrder[k]]) == 0) {
                        r++;
                }
                else {
                        while (r > 15) {
                                bufferIt(outStream, ((int[][])AC_matrix[ACcode])[0xF0][0], ((int[][])AC_matrix[ACcode])[0xF0][1]);
                                r -= 16;
                        }
                        temp2 = temp;
                        if (temp < 0) {
                                temp = -temp;
                                temp2--;
                        }
                        nbits = 1;
                        while ((temp >>= 1) != 0) {
                                nbits++;
                        }
                        i = (r << 4) + nbits;
                        bufferIt(outStream, ((int[][])AC_matrix[ACcode])[i][0], ((int[][])AC_matrix[ACcode])[i][1]);
                        bufferIt(outStream, temp2, nbits);

                        r = 0;
                }
        }

        if (r > 0) {
                bufferIt(outStream, ((int[][])AC_matrix[ACcode])[0][0], ((int[][])AC_matrix[ACcode])[0][1]);
        }

	}

// Uses an integer long (32 bits) buffer to store the Huffman encoded bits
// and sends them to outStream by the byte.

        void bufferIt(BufferedOutputStream outStream, int code,int size)
	{
        int PutBuffer = code;
        int PutBits = bufferPutBits;

        PutBuffer &= (1 << size) - 1;
        PutBits += size;
        PutBuffer <<= 24 - PutBits;
        PutBuffer |= bufferPutBuffer;

        while(PutBits >= 8) {
                int c = ((PutBuffer >> 16) & 0xFF);
                try
                {
                        outStream.write(c);
                }
                catch (IOException e) {