Java tutorial
// Copyright (C) 1998, James R. Weeks and BioElectroMech. // Visit BioElectroMech at www.obrador.com. Email James@obrador.com. // This software is based in part on the work of the Independent JPEG Group. // See license.txt for details about the allowed used of this software. // See IJGreadme.txt for details about the Independent JPEG Group's license. import java.awt.AWTException; import java.awt.Frame; import java.awt.Image; import java.awt.MediaTracker; import java.awt.Toolkit; import java.awt.image.PixelGrabber; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.OutputStream; import java.util.Vector; public class Jpeg { /** ************ Main Method *************** */ /***************************************************************************** * Jpeg("Imagefile", Quality, "OutFileName") According to JAVA virtual * machine, the files which can be read are jpeg, tiff and gif files ****************************************************************************/ public static void StandardUsage() { System.out.println("JpegEncoder for Java(tm) Version 0.9"); System.out.println(""); System.out.println("Program usage: java Jpeg \"InputImage\".\"ext\" Quality [\"OutputFile\"[.jpg]]"); System.out.println(""); System.out.println("Where \"InputImage\" is the name of an existing image in the current directory."); System.out.println(" (\"InputImage may specify a directory, too.) \"ext\" must be .tif, .gif,"); System.out.println(" or .jpg."); System.out.println("Quality is an integer (0 to 100) that specifies how similar the compressed"); System.out.println(" image is to \"InputImage.\" 100 is almost exactly like \"InputImage\" and 0 is"); System.out.println(" most dissimilar. In most cases, 70 - 80 gives very good results."); System.out.println("\"OutputFile\" is an optional argument. If \"OutputFile\" isn't specified, then"); System.out.println(" the input file name is adopted. This program will NOT write over an existing"); System.out.println(" file. If a directory is specified for the input image, then \"OutputFile\""); System.out.println(" will be written in that directory. The extension \".jpg\" may automatically be"); System.out.println(" added."); System.out.println(""); System.out.println("Copyright 1998 BioElectroMech and James R. Weeks. Portions copyright IJG and"); System.out.println(" Florian Raemy, LCAV. See license.txt for details."); System.out.println("Visit BioElectroMech at www.obrador.com. Email James@obrador.com."); System.exit(0); } public static void main(String args[]) { Image image = null; FileOutputStream dataOut = null; File file, outFile; JpegEncoder jpg; String string = ""; int i, Quality = 80; // Check to see if the input file name has one of the extensions: // .tif, .gif, .jpg // If not, print the standard use info. if (args.length < 2) StandardUsage(); if (!args[0].endsWith(".jpg") && !args[0].endsWith(".tif") && !args[0].endsWith(".gif")) StandardUsage(); // First check to see if there is an OutputFile argument. If there isn't // then name the file "InputFile".jpg // Second check to see if the .jpg extension is on the OutputFile argument. // If there isn't one, add it. // Need to check for the existence of the output file. If it exists already, // rename the file with a # after the file name, then the .jpg extension. if (args.length < 3) { string = args[0].substring(0, args[0].lastIndexOf(".")) + ".jpg"; } else { string = args[2]; if (string.endsWith(".tif") || string.endsWith(".gif")) string = string.substring(0, string.lastIndexOf(".")); if (!string.endsWith(".jpg")) string = string.concat(".jpg"); } outFile = new File(string); i = 1; while (outFile.exists()) { outFile = new File(string.substring(0, string.lastIndexOf(".")) + (i++) + ".jpg"); if (i > 100) System.exit(0); } file = new File(args[0]); if (file.exists()) { try { dataOut = new FileOutputStream(outFile); } catch (IOException e) { } try { Quality = Integer.parseInt(args[1]); } catch (NumberFormatException e) { StandardUsage(); } image = Toolkit.getDefaultToolkit().getImage(args[0]); jpg = new JpegEncoder(image, Quality, dataOut); jpg.Compress(); try { dataOut.close(); } catch (IOException e) { } } else { System.out.println("I couldn't find " + args[0] + ". Is it in another directory?"); } System.exit(0); } } // Version 1.0a // Copyright (C) 1998, James R. Weeks and BioElectroMech. // Visit BioElectroMech at www.obrador.com. Email James@obrador.com. // See license.txt for details about the allowed used of this software. // This software is based in part on the work of the Independent JPEG Group. // See IJGreadme.txt for details about the Independent JPEG Group's license. // This encoder is inspired by the Java Jpeg encoder by Florian Raemy, // studwww.eurecom.fr/~raemy. // It borrows a great deal of code and structure from the Independent // Jpeg Group's Jpeg 6a library, Copyright Thomas G. Lane. // See license.txt for details. /* * JpegEncoder - The JPEG main program which performs a jpeg compression of an * image. */ class JpegEncoder extends Frame { Thread runner; BufferedOutputStream outStream; Image image; JpegInfo JpegObj; Huffman Huf; DCT dct; int imageHeight, imageWidth; int Quality; int code; 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, }; public JpegEncoder(Image image, int quality, OutputStream out) { MediaTracker tracker = new MediaTracker(this); tracker.addImage(image, 0); try { tracker.waitForID(0); } catch (InterruptedException e) { // Got to do something? } /* * Quality of the image. 0 to 100 and from bad image quality, high * compression to good image quality low compression */ Quality = quality; /* * Getting picture information It takes the Width, Height and RGB scans of * the image. */ JpegObj = new JpegInfo(image); imageHeight = JpegObj.imageHeight; imageWidth = JpegObj.imageWidth; outStream = new BufferedOutputStream(out); dct = new DCT(Quality); Huf = new Huffman(imageWidth, imageHeight); } public void setQuality(int quality) { dct = new DCT(quality); } public int getQuality() { return Quality; } public void Compress() { WriteHeaders(outStream); WriteCompressedData(outStream); WriteEOI(outStream); try { outStream.flush(); } catch (IOException e) { System.out.println("IO Error: " + e.getMessage()); } } public void WriteCompressedData(BufferedOutputStream outStream) { int i, j, r, c, a, b; int comp, xpos, ypos, xblockoffset, yblockoffset; float inputArray[][]; float dctArray1[][] = new float[8][8]; double dctArray2[][] = new double[8][8]; int dctArray3[] = new int[8 * 8]; /* * This method controls the compression of the image. Starting at the upper * left of the image, it compresses 8x8 blocks of data until the entire * image has been compressed. */ int lastDCvalue[] = new int[JpegObj.NumberOfComponents]; // int zeroArray[] = new int[64]; // initialized to hold all zeros // int Width = 0, Height = 0; // int nothing = 0, not; int MinBlockWidth, MinBlockHeight; // This initial setting of MinBlockWidth and MinBlockHeight is done to // ensure they start with values larger than will actually be the case. MinBlockWidth = ((imageWidth % 8 != 0) ? (int) (Math.floor(imageWidth / 8.0) + 1) * 8 : imageWidth); MinBlockHeight = ((imageHeight % 8 != 0) ? (int) (Math.floor(imageHeight / 8.0) + 1) * 8 : imageHeight); for (comp = 0; comp < JpegObj.NumberOfComponents; comp++) { MinBlockWidth = Math.min(MinBlockWidth, JpegObj.BlockWidth[comp]); MinBlockHeight = Math.min(MinBlockHeight, JpegObj.BlockHeight[comp]); } xpos = 0; for (r = 0; r < MinBlockHeight; r++) { for (c = 0; c < MinBlockWidth; c++) { xpos = c * 8; ypos = r * 8; for (comp = 0; comp < JpegObj.NumberOfComponents; comp++) { // Width = JpegObj.BlockWidth[comp]; // Height = JpegObj.BlockHeight[comp]; inputArray = (float[][]) JpegObj.Components[comp]; for (i = 0; i < JpegObj.VsampFactor[comp]; i++) { for (j = 0; j < JpegObj.HsampFactor[comp]; j++) { xblockoffset = j * 8; yblockoffset = i * 8; for (a = 0; a < 8; a++) { for (b = 0; b < 8; b++) { // I believe this is where the dirty line at the bottom of // the image is coming from. // I need to do a check here to make sure I'm not reading past // image data. // This seems to not be a big issue right now. (04/04/98) dctArray1[a][b] = inputArray[ypos + yblockoffset + a][xpos + xblockoffset + b]; } } // The following code commented out because on some images this // technique // results in poor right and bottom borders. // if ((!JpegObj.lastColumnIsDummy[comp] || c < Width - 1) && // (!JpegObj.lastRowIsDummy[comp] || r < Height - 1)) { dctArray2 = dct.forwardDCT(dctArray1); dctArray3 = dct.quantizeBlock(dctArray2, JpegObj.QtableNumber[comp]); // } // else { // zeroArray[0] = dctArray3[0]; // zeroArray[0] = lastDCvalue[comp]; // dctArray3 = zeroArray; // } Huf.HuffmanBlockEncoder(outStream, dctArray3, lastDCvalue[comp], JpegObj.DCtableNumber[comp], JpegObj.ACtableNumber[comp]); lastDCvalue[comp] = dctArray3[0]; } } } } } Huf.flushBuffer(outStream); } public void WriteEOI(BufferedOutputStream out) { byte[] EOI = { (byte) 0xFF, (byte) 0xD9 }; WriteMarker(EOI, out); } public void WriteHeaders(BufferedOutputStream out) { int i, j, index, offset, length; int tempArray[]; // the SOI marker byte[] SOI = { (byte) 0xFF, (byte) 0xD8 }; WriteMarker(SOI, out); // The order of the following headers is quiet inconsequential. // the JFIF header byte JFIF[] = new byte[18]; JFIF[0] = (byte) 0xff; JFIF[1] = (byte) 0xe0; JFIF[2] = (byte) 0x00; JFIF[3] = (byte) 0x10; JFIF[4] = (byte) 0x4a; JFIF[5] = (byte) 0x46; JFIF[6] = (byte) 0x49; JFIF[7] = (byte) 0x46; JFIF[8] = (byte) 0x00; JFIF[9] = (byte) 0x01; JFIF[10] = (byte) 0x00; JFIF[11] = (byte) 0x00; JFIF[12] = (byte) 0x00; JFIF[13] = (byte) 0x01; JFIF[14] = (byte) 0x00; JFIF[15] = (byte) 0x01; JFIF[16] = (byte) 0x00; JFIF[17] = (byte) 0x00; WriteArray(JFIF, out); // Comment Header String comment = ""; comment = JpegObj.getComment(); length = comment.length(); byte COM[] = new byte[length + 4]; COM[0] = (byte) 0xFF; COM[1] = (byte) 0xFE; COM[2] = (byte) ((length >> 8) & 0xFF); COM[3] = (byte) (length & 0xFF); java.lang.System.arraycopy(JpegObj.Comment.getBytes(), 0, COM, 4, JpegObj.Comment.length()); WriteArray(COM, out); // The DQT header // 0 is the luminance index and 1 is the chrominance index byte DQT[] = new byte[134]; DQT[0] = (byte) 0xFF; DQT[1] = (byte) 0xDB; DQT[2] = (byte) 0x00; DQT[3] = (byte) 0x84; offset = 4; for (i = 0; i < 2; i++) { DQT[offset++] = (byte) ((0 << 4) + i); tempArray = (int[]) dct.quantum[i]; for (j = 0; j < 64; j++) { DQT[offset++] = (byte) tempArray[jpegNaturalOrder[j]]; } } WriteArray(DQT, out); // Start of Frame Header byte SOF[] = new byte[19]; SOF[0] = (byte) 0xFF; SOF[1] = (byte) 0xC0; SOF[2] = (byte) 0x00; SOF[3] = (byte) 17; SOF[4] = (byte) JpegObj.Precision; SOF[5] = (byte) ((JpegObj.imageHeight >> 8) & 0xFF); SOF[6] = (byte) ((JpegObj.imageHeight) & 0xFF); SOF[7] = (byte) ((JpegObj.imageWidth >> 8) & 0xFF); SOF[8] = (byte) ((JpegObj.imageWidth) & 0xFF); SOF[9] = (byte) JpegObj.NumberOfComponents; index = 10; for (i = 0; i < SOF[9]; i++) { SOF[index++] = (byte) JpegObj.CompID[i]; SOF[index++] = (byte) ((JpegObj.HsampFactor[i] << 4) + JpegObj.VsampFactor[i]); SOF[index++] = (byte) JpegObj.QtableNumber[i]; } WriteArray(SOF, out); // The DHT Header byte DHT1[], DHT2[], DHT3[], DHT4[]; int bytes, temp, oldindex, intermediateindex; length = 2; index = 4; oldindex = 4; DHT1 = new byte[17]; DHT4 = new byte[4]; DHT4[0] = (byte) 0xFF; DHT4[1] = (byte) 0xC4; for (i = 0; i < 4; i++) { bytes = 0; DHT1[index++ - oldindex] = (byte) ((int[]) Huf.bits.elementAt(i))[0]; for (j = 1; j < 17; j++) { temp = ((int[]) Huf.bits.elementAt(i))[j]; DHT1[index++ - oldindex] = (byte) temp; bytes += temp; } intermediateindex = index; DHT2 = new byte[bytes]; for (j = 0; j < bytes; j++) { DHT2[index++ - intermediateindex] = (byte) ((int[]) Huf.val.elementAt(i))[j]; } DHT3 = new byte[index]; java.lang.System.arraycopy(DHT4, 0, DHT3, 0, oldindex); java.lang.System.arraycopy(DHT1, 0, DHT3, oldindex, 17); java.lang.System.arraycopy(DHT2, 0, DHT3, oldindex + 17, bytes); DHT4 = DHT3; oldindex = index; } DHT4[2] = (byte) (((index - 2) >> 8) & 0xFF); DHT4[3] = (byte) ((index - 2) & 0xFF); WriteArray(DHT4, out); // Start of Scan Header byte SOS[] = new byte[14]; SOS[0] = (byte) 0xFF; SOS[1] = (byte) 0xDA; SOS[2] = (byte) 0x00; SOS[3] = (byte) 12; SOS[4] = (byte) JpegObj.NumberOfComponents; index = 5; for (i = 0; i < SOS[4]; i++) { SOS[index++] = (byte) JpegObj.CompID[i]; SOS[index++] = (byte) ((JpegObj.DCtableNumber[i] << 4) + JpegObj.ACtableNumber[i]); } SOS[index++] = (byte) JpegObj.Ss; SOS[index++] = (byte) JpegObj.Se; SOS[index++] = (byte) ((JpegObj.Ah << 4) + JpegObj.Al); WriteArray(SOS, out); } void WriteMarker(byte[] data, BufferedOutputStream out) { try { out.write(data, 0, 2); } catch (IOException e) { System.out.println("IO Error: " + e.getMessage()); } } void WriteArray(byte[] data, BufferedOutputStream out) { int length; try { length = ((data[2] & 0xFF) << 8) + (data[3] & 0xFF) + 2; out.write(data, 0, length); } catch (IOException e) { System.out.println("IO Error: " + e.getMessage()); } } } // This class incorporates quality scaling as implemented in the JPEG-6a // library. /* * DCT - A Java implementation of the Discreet Cosine Transform */ class DCT { /** * DCT Block Size - default 8 */ public int N = 8; /** * Image Quality (0-100) - default 80 (good image / good compression) */ public int QUALITY = 80; public Object quantum[] = new Object[2]; public Object Divisors[] = new Object[2]; /** * Quantitization Matrix for luminace. */ public int quantum_luminance[] = new int[N * N]; public double DivisorsLuminance[] = new double[N * N]; /** * Quantitization Matrix for chrominance. */ public int quantum_chrominance[] = new int[N * N]; public double DivisorsChrominance[] = new double[N * N]; /** * Constructs a new DCT object. Initializes the cosine transform matrix these * are used when computing the DCT and it's inverse. This also initializes the * run length counters and the ZigZag sequence. Note that the image quality * can be worse than 25 however the image will be extemely pixelated, usually * to a block size of N. * * @param QUALITY * The quality of the image (0 worst - 100 best) * */ public DCT(int QUALITY) { initMatrix(QUALITY); } /* * This method sets up the quantization matrix for luminance and chrominance * using the Quality parameter. */ private void initMatrix(int quality) { double[] AANscaleFactor = { 1.0, 1.387039845, 1.306562965, 1.175875602, 1.0, 0.785694958, 0.541196100, 0.275899379 }; int i; int j; int index; int Quality; int temp; // converting quality setting to that specified in the jpeg_quality_scaling // method in the IJG Jpeg-6a C libraries Quality = quality; if (Quality <= 0) Quality = 1; if (Quality > 100) Quality = 100; if (Quality < 50) Quality = 5000 / Quality; else Quality = 200 - Quality * 2; // Creating the luminance matrix quantum_luminance[0] = 16; quantum_luminance[1] = 11; quantum_luminance[2] = 10; quantum_luminance[3] = 16; quantum_luminance[4] = 24; quantum_luminance[5] = 40; quantum_luminance[6] = 51; quantum_luminance[7] = 61; quantum_luminance[8] = 12; quantum_luminance[9] = 12; quantum_luminance[10] = 14; quantum_luminance[11] = 19; quantum_luminance[12] = 26; quantum_luminance[13] = 58; quantum_luminance[14] = 60; quantum_luminance[15] = 55; quantum_luminance[16] = 14; quantum_luminance[17] = 13; quantum_luminance[18] = 16; quantum_luminance[19] = 24; quantum_luminance[20] = 40; quantum_luminance[21] = 57; quantum_luminance[22] = 69; quantum_luminance[23] = 56; quantum_luminance[24] = 14; quantum_luminance[25] = 17; quantum_luminance[26] = 22; quantum_luminance[27] = 29; quantum_luminance[28] = 51; quantum_luminance[29] = 87; quantum_luminance[30] = 80; quantum_luminance[31] = 62; quantum_luminance[32] = 18; quantum_luminance[33] = 22; quantum_luminance[34] = 37; quantum_luminance[35] = 56; quantum_luminance[36] = 68; quantum_luminance[37] = 109; quantum_luminance[38] = 103; quantum_luminance[39] = 77; quantum_luminance[40] = 24; quantum_luminance[41] = 35; quantum_luminance[42] = 55; quantum_luminance[43] = 64; quantum_luminance[44] = 81; quantum_luminance[45] = 104; quantum_luminance[46] = 113; quantum_luminance[47] = 92; quantum_luminance[48] = 49; quantum_luminance[49] = 64; quantum_luminance[50] = 78; quantum_luminance[51] = 87; quantum_luminance[52] = 103; quantum_luminance[53] = 121; quantum_luminance[54] = 120; quantum_luminance[55] = 101; quantum_luminance[56] = 72; quantum_luminance[57] = 92; quantum_luminance[58] = 95; quantum_luminance[59] = 98; quantum_luminance[60] = 112; quantum_luminance[61] = 100; quantum_luminance[62] = 103; quantum_luminance[63] = 99; for (j = 0; j < 64; j++) { temp = (quantum_luminance[j] * Quality + 50) / 100; if (temp <= 0) temp = 1; if (temp > 255) temp = 255; quantum_luminance[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. // DivisorsLuminance[index] = ((double) quantum_luminance[index]) << 3; // The divisors for the AAN method (the float method used in jpeg 6a // library. DivisorsLuminance[index] = (1.0 / (quantum_luminance[index] * AANscaleFactor[i] * AANscaleFactor[j] * 8.0)); index++; } } // Creating the chrominance matrix quantum_chrominance[0] = 17; quantum_chrominance[1] = 18; quantum_chrominance[2] = 24; quantum_chrominance[3] = 47; quantum_chrominance[4] = 99; quantum_chrominance[5] = 99; quantum_chrominance[6] = 99; quantum_chrominance[7] = 99; quantum_chrominance[8] = 18; quantum_chrominance[9] = 21; quantum_chrominance[10] = 26; quantum_chrominance[11] = 66; quantum_chrominance[12] = 99; quantum_chrominance[13] = 99; quantum_chrominance[14] = 99; quantum_chrominance[15] = 99; quantum_chrominance[16] = 24; quantum_chrominance[17] = 26; quantum_chrominance[18] = 56; quantum_chrominance[19] = 99; quantum_chrominance[20] = 99; quantum_chrominance[21] = 99; quantum_chrominance[22] = 99; quantum_chrominance[23] = 99; quantum_chrominance[24] = 47; quantum_chrominance[25] = 66; quantum_chrominance[26] = 99; quantum_chrominance[27] = 99; quantum_chrominance[28] = 99; quantum_chrominance[29] = 99; quantum_chrominance[30] = 99; quantum_chrominance[31] = 99; quantum_chrominance[32] = 99; quantum_chrominance[33] = 99; quantum_chrominance[34] = 99; quantum_chrominance[35] = 99; quantum_chrominance[36] = 99; 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] = 1.0 / (quantum_chrominance[index] * AANscaleFactor[i] * AANscaleFactor[j] * 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]; 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] += input[x][y] * Math.cos(((double) (2 * x + 1) * (double) u * Math.PI) / 16) * Math.cos(((double) (2 * y + 1) * (double) v * Math.PI) / 16); } } output[v][u] *= (0.25) * ((u == 0) ? (1.0 / Math.sqrt(2)) : (double) 1.0) * ((v == 0) ? (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] = (input[i][j] - 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) * 0.707106781; output[i][2] = tmp13 + z1; output[i][6] = tmp13 - z1; tmp10 = tmp4 + tmp5; tmp11 = tmp5 + tmp6; tmp12 = tmp6 + tmp7; z5 = (tmp10 - tmp12) * 0.382683433; z2 = 0.541196100 * tmp10 + z5; z4 = 1.306562965 * tmp12 + z5; z3 = tmp11 * 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) * 0.707106781; output[2][i] = tmp13 + z1; output[6][i] = tmp13 - z1; tmp10 = tmp4 + tmp5; tmp11 = tmp5 + tmp6; tmp12 = tmp6 + tmp7; z5 = (tmp10 - tmp12) * 0.382683433; z2 = 0.541196100 * tmp10 + z5; z4 = 1.306562965 * tmp12 + z5; z3 = tmp11 * 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] / (((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(); ImageWidth = Width; ImageHeight = Height; } /** * HuffmanBlockEncoder run length encodes and Huffman encodes the quantized * data. * * @param outStream * @param zigzag * @param prec * @param DCcode * @param ACcode */ 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) { System.out.println("IO Error: " + e.getMessage()); } if (c == 0xFF) { try { outStream.write(0); } catch (IOException e) { System.out.println("IO Error: " + e.getMessage()); } } PutBuffer <<= 8; PutBits -= 8; } bufferPutBuffer = PutBuffer; bufferPutBits = PutBits; } void flushBuffer(BufferedOutputStream outStream) { int PutBuffer = bufferPutBuffer; int PutBits = bufferPutBits; while (PutBits >= 8) { int c = ((PutBuffer >> 16) & 0xFF); try { outStream.write(c); } catch (IOException e) { System.out.println("IO Error: " + e.getMessage()); } if (c == 0xFF) { try { outStream.write(0); } catch (IOException e) { System.out.println("IO Error: " + e.getMessage()); } } PutBuffer <<= 8; PutBits -= 8; } if (PutBits > 0) { int c = ((PutBuffer >> 16) & 0xFF); try { outStream.write(c); } catch (IOException e) { System.out.println("IO Error: " + e.getMessage()); } } } /* * Initialisation of the Huffman codes for Luminance and Chrominance. This * code results in the same tables created in the IJG Jpeg-6a library. */ public void initHuf() { DC_matrix0 = new int[12][2]; DC_matrix1 = new int[12][2]; AC_matrix0 = new int[255][2]; AC_matrix1 = new int[255][2]; DC_matrix = new Object[2]; AC_matrix = new Object[2]; int p, l, i, lastp, si, code; int[] huffsize = new int[257]; int[] huffcode = new int[257]; /* * init of the DC values for the chrominance [][0] is the code [][1] is the * number of bit */ p = 0; for (l = 1; l <= 16; l++) { for (i = 1; i <= bitsDCchrominance[l]; i++) { huffsize[p++] = l; } } huffsize[p] = 0; lastp = p; code = 0; si = huffsize[0]; p = 0; while (huffsize[p] != 0) { while (huffsize[p] == si) { huffcode[p++] = code; code++; } code <<= 1; si++; } for (p = 0; p < lastp; p++) { DC_matrix1[valDCchrominance[p]][0] = huffcode[p]; DC_matrix1[valDCchrominance[p]][1] = huffsize[p]; } /* * Init of the AC hufmann code for the chrominance matrix [][][0] is the * code & matrix[][][1] is the number of bit needed */ p = 0; for (l = 1; l <= 16; l++) { for (i = 1; i <= bitsACchrominance[l]; i++) { huffsize[p++] = l; } } huffsize[p] = 0; lastp = p; code = 0; si = huffsize[0]; p = 0; while (huffsize[p] != 0) { while (huffsize[p] == si) { huffcode[p++] = code; code++; } code <<= 1; si++; } for (p = 0; p < lastp; p++) { AC_matrix1[valACchrominance[p]][0] = huffcode[p]; AC_matrix1[valACchrominance[p]][1] = huffsize[p]; } /* * init of the DC values for the luminance [][0] is the code [][1] is the * number of bit */ p = 0; for (l = 1; l <= 16; l++) { for (i = 1; i <= bitsDCluminance[l]; i++) { huffsize[p++] = l; } } huffsize[p] = 0; lastp = p; code = 0; si = huffsize[0]; p = 0; while (huffsize[p] != 0) { while (huffsize[p] == si) { huffcode[p++] = code; code++; } code <<= 1; si++; } for (p = 0; p < lastp; p++) { DC_matrix0[valDCluminance[p]][0] = huffcode[p]; DC_matrix0[valDCluminance[p]][1] = huffsize[p]; } /* * Init of the AC hufmann code for luminance matrix [][][0] is the code & * matrix[][][1] is the number of bit */ p = 0; for (l = 1; l <= 16; l++) { for (i = 1; i <= bitsACluminance[l]; i++) { huffsize[p++] = l; } } huffsize[p] = 0; lastp = p; code = 0; si = huffsize[0]; p = 0; while (huffsize[p] != 0) { while (huffsize[p] == si) { huffcode[p++] = code; code++; } code <<= 1; si++; } for (int q = 0; q < lastp; q++) { AC_matrix0[valACluminance[q]][0] = huffcode[q]; AC_matrix0[valACluminance[q]][1] = huffsize[q]; } DC_matrix[0] = DC_matrix0; DC_matrix[1] = DC_matrix1; AC_matrix[0] = AC_matrix0; AC_matrix[1] = AC_matrix1; } } /* * JpegInfo - Given an image, sets default information about it and divides it * into its constituant components, downsizing those that need to be. */ class JpegInfo { String Comment; public Image imageobj; public int imageHeight; public int imageWidth; public int BlockWidth[]; public int BlockHeight[]; // the following are set as the default public int Precision = 8; public int NumberOfComponents = 3; public Object Components[]; public int[] CompID = { 1, 2, 3 }; public int[] HsampFactor = { 1, 1, 1 }; public int[] VsampFactor = { 1, 1, 1 }; public int[] QtableNumber = { 0, 1, 1 }; public int[] DCtableNumber = { 0, 1, 1 }; public int[] ACtableNumber = { 0, 1, 1 }; public boolean[] lastColumnIsDummy = { false, false, false }; public boolean[] lastRowIsDummy = { false, false, false }; public int Ss = 0; public int Se = 63; public int Ah = 0; public int Al = 0; public int compWidth[], compHeight[]; public int MaxHsampFactor; public int MaxVsampFactor; public JpegInfo(Image image) { Components = new Object[NumberOfComponents]; compWidth = new int[NumberOfComponents]; compHeight = new int[NumberOfComponents]; BlockWidth = new int[NumberOfComponents]; BlockHeight = new int[NumberOfComponents]; imageobj = image; imageWidth = image.getWidth(null); imageHeight = image.getHeight(null); Comment = "JPEG Encoder Copyright 1998, James R. Weeks and BioElectroMech. "; getYCCArray(); } public void setComment(String comment) { Comment.concat(comment); } public String getComment() { return Comment; } /* * This method creates and fills three arrays, Y, Cb, and Cr using the input * image. */ private void getYCCArray() { int values[] = new int[imageWidth * imageHeight]; int r, g, b, y, x; // In order to minimize the chance that grabPixels will throw an exception // it may be necessary to grab some pixels every few scanlines and process // those before going for more. The time expense may be prohibitive. // However, for a situation where memory overhead is a concern, this may be // the only choice. PixelGrabber grabber = new PixelGrabber(imageobj.getSource(), 0, 0, imageWidth, imageHeight, values, 0, imageWidth); MaxHsampFactor = 1; MaxVsampFactor = 1; for (y = 0; y < NumberOfComponents; y++) { MaxHsampFactor = Math.max(MaxHsampFactor, HsampFactor[y]); MaxVsampFactor = Math.max(MaxVsampFactor, VsampFactor[y]); } for (y = 0; y < NumberOfComponents; y++) { compWidth[y] = (((imageWidth % 8 != 0) ? ((int) Math.ceil(imageWidth / 8.0)) * 8 : imageWidth) / MaxHsampFactor) * HsampFactor[y]; if (compWidth[y] != ((imageWidth / MaxHsampFactor) * HsampFactor[y])) { lastColumnIsDummy[y] = true; } // results in a multiple of 8 for compWidth // this will make the rest of the program fail for the unlikely // event that someone tries to compress an 16 x 16 pixel image // which would of course be worse than pointless BlockWidth[y] = (int) Math.ceil(compWidth[y] / 8.0); compHeight[y] = (((imageHeight % 8 != 0) ? ((int) Math.ceil(imageHeight / 8.0)) * 8 : imageHeight) / MaxVsampFactor) * VsampFactor[y]; if (compHeight[y] != ((imageHeight / MaxVsampFactor) * VsampFactor[y])) { lastRowIsDummy[y] = true; } BlockHeight[y] = (int) Math.ceil(compHeight[y] / 8.0); } try { if (grabber.grabPixels() != true) { try { throw new AWTException("Grabber returned false: " + grabber.status()); } catch (Exception e) { } } } catch (InterruptedException e) { } float Y[][] = new float[compHeight[0]][compWidth[0]]; float Cr1[][] = new float[compHeight[0]][compWidth[0]]; float Cb1[][] = new float[compHeight[0]][compWidth[0]]; // float Cb2[][] = new float[compHeight[1]][compWidth[1]]; // float Cr2[][] = new float[compHeight[2]][compWidth[2]]; int index = 0; for (y = 0; y < imageHeight; ++y) { for (x = 0; x < imageWidth; ++x) { r = ((values[index] >> 16) & 0xff); g = ((values[index] >> 8) & 0xff); b = (values[index] & 0xff); // The following three lines are a more correct color conversion but // the current conversion technique is sufficient and results in a // higher // compression rate. // Y[y][x] = 16 + (float)(0.8588*(0.299 * (float)r + 0.587 * (float)g + // 0.114 * (float)b )); // Cb1[y][x] = 128 + (float)(0.8784*(-0.16874 * (float)r - 0.33126 * // (float)g + 0.5 * (float)b)); // Cr1[y][x] = 128 + (float)(0.8784*(0.5 * (float)r - 0.41869 * (float)g // - 0.08131 * (float)b)); Y[y][x] = (float) ((0.299 * r + 0.587 * g + 0.114 * b)); Cb1[y][x] = 128 + (float) ((-0.16874 * r - 0.33126 * g + 0.5 * b)); Cr1[y][x] = 128 + (float) ((0.5 * r - 0.41869 * g - 0.08131 * b)); index++; } } // Need a way to set the H and V sample factors before allowing // downsampling. // For now (04/04/98) downsampling must be hard coded. // Until a better downsampler is implemented, this will not be done. // Downsampling is currently supported. The downsampling method here // is a simple box filter. Components[0] = Y; // Cb2 = DownSample(Cb1, 1); Components[1] = Cb1; // Cr2 = DownSample(Cr1, 2); Components[2] = Cr1; } float[][] DownSample(float[][] C, int comp) { int inrow, incol; int outrow, outcol; float output[][]; int bias; inrow = 0; incol = 0; output = new float[compHeight[comp]][compWidth[comp]]; for (outrow = 0; outrow < compHeight[comp]; outrow++) { bias = 1; for (outcol = 0; outcol < compWidth[comp]; outcol++) { output[outrow][outcol] = (C[inrow][incol++] + C[inrow++][incol--] + C[inrow][incol++] + C[inrow--][incol++] + bias) / (float) 4.0; bias ^= 3; } inrow += 2; incol = 0; } return output; } }