// JpegEncoder - write out an image as a JPEG // // Copyright (C) 1996 by Jef Poskanzer . All rights reserved. // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions // are met: // 1. Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // 2. Redistributions in binary form must reproduce the above copyright // notice, this list of conditions and the following disclaimer in the // documentation and/or other materials provided with the distribution. // // THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE // ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS // OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) // HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT // LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY // OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF // SUCH DAMAGE. // // Visit the ACME Labs Java page for up-to-date versions of this and other // fine Java utilities: http://www.acme.com/java/ package Acme.JPM.Encoders; import java.util.*; import java.io.*; import java.awt.Image; import java.awt.image.*; /// Write out an image as a JPEG. // DOESN'T WORK YET. //

// Fetch the software.
// Fetch the entire Acme package. //

// @see ToJpeg public class JpegEncoder extends ImageEncoder { /// Constructor. // @param img The image to encode. // @param out The stream to write the JPEG to. public JpegEncoder( Image img, OutputStream out ) throws IOException { super( img, out ); } /// Constructor. // @param prod The ImageProducer to encode. // @param out The stream to write the JPEG to. public JpegEncoder( ImageProducer prod, OutputStream out ) throws IOException { super( prod, out ); } int qfactor = 100; /// Set the Q-factor. public void setQfactor( int qfactor ) { this.qfactor = qfactor; } int width, height; int[][] rgbPixels; void encodeStart( int width, int height ) throws IOException { this.width = width; this.height = height; rgbPixels = new int[height][width]; } void encodePixels( int x, int y, int w, int h, int[] rgbPixels, int off, int scansize ) throws IOException { // Save the pixels. for ( int row = 0; row < h; ++row ) System.arraycopy( rgbPixels, row * scansize + off, this.rgbPixels[y + row], x, w ); } void encodeDone() throws IOException { writeJfifHuffHeader(); // !!! } // Some of the following code is derived from the Berkeley Continuous // Media Toolkit (http://bmrc.berkeley.edu/projects/cmt/), which is // Copyright (c) 1996 The Regents of the University of California. // All rights reserved. // // IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR // DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING // OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE // UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH // DAMAGE. // // THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES, // INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY // AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS // ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION // TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. // This array represents the default JFIF header for quality = 100 and // size = 640x480, with Huffman tables. The values are adjusted when a // file is generated. private static byte[] jfifHuff100Header = { // SOI (byte) 0xFF, (byte) 0xD8, // JFIF header (byte) 0xFF, (byte) 0xE0, // Marker (byte) 0x00, (byte) 0x10, // Length = 16 bytes (byte) 0x4A, (byte) 0x46, (byte) 0x49, (byte) 0x46, // "JFIF" (byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x00, // Start of frame (section B.2.2) (byte) 0xFF, (byte) 0xC0, // Baseline DCT (byte) 0x00, (byte) 0x11, // Length = 17 bytes (byte) 0x08, // Sample precision (byte) 0x01, (byte) 0xE0, // Height (byte) 0x02, (byte) 0x80, // Width (byte) 0x03, // Number of components = 3 // Scan 1: 2:1 horiz, (byte) 1:1 vertical, (byte) use QT 0 (byte) 0x01, (byte) 0x21, (byte) 0x00, // Scan 2: 1:1 horiz, (byte) 1:1 vertical, (byte) use QT 1 (byte) 0x02, (byte) 0x11, (byte) 0x01, // Scan 3: 1:1 horiz, (byte) 1:1 vertical, (byte) use QT 1 (byte) 0x03, (byte) 0x11, (byte) 0x01, // Define Quant table (section B.2.4.1) (byte) 0xFF, (byte) 0xDB, // Marker (byte) 0x00, (byte) 0x84, // Length (both tables) (byte) 0x00, // 8 bit values, (byte) table 0 (byte) 0x10, (byte) 0x0B, (byte) 0x0C, (byte) 0x0E, (byte) 0x0C, (byte) 0x0A, (byte) 0x10, (byte) 0x0E, (byte) 0x0D, (byte) 0x0E, (byte) 0x12, (byte) 0x11, (byte) 0x10, (byte) 0x13, (byte) 0x18, (byte) 0x28, (byte) 0x1A, (byte) 0x18, (byte) 0x16, (byte) 0x16, (byte) 0x18, (byte) 0x31, (byte) 0x23, (byte) 0x25, (byte) 0x1D, (byte) 0x28, (byte) 0x3A, (byte) 0x33, (byte) 0x3D, (byte) 0x3C, (byte) 0x39, (byte) 0x33, (byte) 0x38, (byte) 0x37, (byte) 0x40, (byte) 0x48, (byte) 0x5C, (byte) 0x4E, (byte) 0x40, (byte) 0x44, (byte) 0x57, (byte) 0x45, (byte) 0x37, (byte) 0x38, (byte) 0x50, (byte) 0x6D, (byte) 0x51, (byte) 0x57, (byte) 0x5F, (byte) 0x62, (byte) 0x67, (byte) 0x68, (byte) 0x67, (byte) 0x3E, (byte) 0x4D, (byte) 0x71, (byte) 0x79, (byte) 0x70, (byte) 0x64, (byte) 0x78, (byte) 0x5C, (byte) 0x65, (byte) 0x67, (byte) 0x63, (byte) 0x01, // 8 bit values, (byte) table 1 (byte) 0x11, (byte) 0x12, (byte) 0x12, (byte) 0x18, (byte) 0x15, (byte) 0x18, (byte) 0x2F, (byte) 0x1A, (byte) 0x1A, (byte) 0x2F, (byte) 0x63, (byte) 0x42, (byte) 0x38, (byte) 0x42, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, // Define huffman table (section B.2.4.1) (byte) 0xFF, (byte) 0xC4, // Marker (byte) 0x00, (byte) 0x1F, // Length (31 bytes) (byte) 0x00, // DC, (byte) table 0 (byte) 0x00, (byte) 0x01, (byte) 0x05, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x02, (byte) 0x03, (byte) 0x04, (byte) 0x05, (byte) 0x06, (byte) 0x07, (byte) 0x08, (byte) 0x09, (byte) 0x0A, (byte) 0x0B, // Define huffman table (section B.2.4.1) (byte) 0xFF, (byte) 0xC4, // Marker (byte) 0x00, (byte) 0xB5, // Length (181 bytes) (byte) 0x10, // AC, (byte) table 0 (byte) 0x00, (byte) 0x02, (byte) 0x01, (byte) 0x03, (byte) 0x03, (byte) 0x02, (byte) 0x04, (byte) 0x03, (byte) 0x05, (byte) 0x05, (byte) 0x04, (byte) 0x04, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x7D, (byte) 0x01, (byte) 0x02, (byte) 0x03, (byte) 0x00, (byte) 0x04, (byte) 0x11, (byte) 0x05, (byte) 0x12, (byte) 0x21, (byte) 0x31, (byte) 0x41, (byte) 0x06, (byte) 0x13, (byte) 0x51, (byte) 0x61, (byte) 0x07, (byte) 0x22, (byte) 0x71, (byte) 0x14, (byte) 0x32, (byte) 0x81, (byte) 0x91, (byte) 0xA1, (byte) 0x08, (byte) 0x23, (byte) 0x42, (byte) 0xB1, (byte) 0xC1, (byte) 0x15, (byte) 0x52, (byte) 0xD1, (byte) 0xF0, (byte) 0x24, (byte) 0x33, (byte) 0x62, (byte) 0x72, (byte) 0x82, (byte) 0x09, (byte) 0x0A, (byte) 0x16, (byte) 0x17, (byte) 0x18, (byte) 0x19, (byte) 0x1A, (byte) 0x25, (byte) 0x26, (byte) 0x27, (byte) 0x28, (byte) 0x29, (byte) 0x2A, (byte) 0x34, (byte) 0x35, (byte) 0x36, (byte) 0x37, (byte) 0x38, (byte) 0x39, (byte) 0x3A, (byte) 0x43, (byte) 0x44, (byte) 0x45, (byte) 0x46, (byte) 0x47, (byte) 0x48, (byte) 0x49, (byte) 0x4A, (byte) 0x53, (byte) 0x54, (byte) 0x55, (byte) 0x56, (byte) 0x57, (byte) 0x58, (byte) 0x59, (byte) 0x5A, (byte) 0x63, (byte) 0x64, (byte) 0x65, (byte) 0x66, (byte) 0x67, (byte) 0x68, (byte) 0x69, (byte) 0x6A, (byte) 0x73, (byte) 0x74, (byte) 0x75, (byte) 0x76, (byte) 0x77, (byte) 0x78, (byte) 0x79, (byte) 0x7A, (byte) 0x83, (byte) 0x84, (byte) 0x85, (byte) 0x86, (byte) 0x87, (byte) 0x88, (byte) 0x89, (byte) 0x8A, (byte) 0x92, (byte) 0x93, (byte) 0x94, (byte) 0x95, (byte) 0x96, (byte) 0x97, (byte) 0x98, (byte) 0x99, (byte) 0x9A, (byte) 0xA2, (byte) 0xA3, (byte) 0xA4, (byte) 0xA5, (byte) 0xA6, (byte) 0xA7, (byte) 0xA8, (byte) 0xA9, (byte) 0xAA, (byte) 0xB2, (byte) 0xB3, (byte) 0xB4, (byte) 0xB5, (byte) 0xB6, (byte) 0xB7, (byte) 0xB8, (byte) 0xB9, (byte) 0xBA, (byte) 0xC2, (byte) 0xC3, (byte) 0xC4, (byte) 0xC5, (byte) 0xC6, (byte) 0xC7, (byte) 0xC8, (byte) 0xC9, (byte) 0xCA, (byte) 0xD2, (byte) 0xD3, (byte) 0xD4, (byte) 0xD5, (byte) 0xD6, (byte) 0xD7, (byte) 0xD8, (byte) 0xD9, (byte) 0xDA, (byte) 0xE1, (byte) 0xE2, (byte) 0xE3, (byte) 0xE4, (byte) 0xE5, (byte) 0xE6, (byte) 0xE7, (byte) 0xE8, (byte) 0xE9, (byte) 0xEA, (byte) 0xF1, (byte) 0xF2, (byte) 0xF3, (byte) 0xF4, (byte) 0xF5, (byte) 0xF6, (byte) 0xF7, (byte) 0xF8, (byte) 0xF9, (byte) 0xFA, // Define huffman table (section B.2.4.1) (byte) 0xFF, (byte) 0xC4, // Marker (byte) 0x00, (byte) 0x1F, // Length (31 bytes) (byte) 0x01, // DC, (byte) table 1 (byte) 0x00, (byte) 0x03, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x02, (byte) 0x03, (byte) 0x04, (byte) 0x05, (byte) 0x06, (byte) 0x07, (byte) 0x08, (byte) 0x09, (byte) 0x0A, (byte) 0x0B, // Define huffman table (section B.2.4.1) (byte) 0xFF, (byte) 0xC4, // Marker (byte) 0x00, (byte) 0xB5, // Length (181 bytes) (byte) 0x11, // AC, (byte) table 1 (byte) 0x00, (byte) 0x02, (byte) 0x01, (byte) 0x02, (byte) 0x04, (byte) 0x04, (byte) 0x03, (byte) 0x04, (byte) 0x07, (byte) 0x05, (byte) 0x04, (byte) 0x04, (byte) 0x00, (byte) 0x01, (byte) 0x02, (byte) 0x77, (byte) 0x00, (byte) 0x01, (byte) 0x02, (byte) 0x03, (byte) 0x11, (byte) 0x04, (byte) 0x05, (byte) 0x21, (byte) 0x31, (byte) 0x06, (byte) 0x12, (byte) 0x41, (byte) 0x51, (byte) 0x07, (byte) 0x61, (byte) 0x71, (byte) 0x13, (byte) 0x22, (byte) 0x32, (byte) 0x81, (byte) 0x08, (byte) 0x14, (byte) 0x42, (byte) 0x91, (byte) 0xA1, (byte) 0xB1, (byte) 0xC1, (byte) 0x09, (byte) 0x23, (byte) 0x33, (byte) 0x52, (byte) 0xF0, (byte) 0x15, (byte) 0x62, (byte) 0x72, (byte) 0xD1, (byte) 0x0A, (byte) 0x16, (byte) 0x24, (byte) 0x34, (byte) 0xE1, (byte) 0x25, (byte) 0xF1, (byte) 0x17, (byte) 0x18, (byte) 0x19, (byte) 0x1A, (byte) 0x26, (byte) 0x27, (byte) 0x28, (byte) 0x29, (byte) 0x2A, (byte) 0x35, (byte) 0x36, (byte) 0x37, (byte) 0x38, (byte) 0x39, (byte) 0x3A, (byte) 0x43, (byte) 0x44, (byte) 0x45, (byte) 0x46, (byte) 0x47, (byte) 0x48, (byte) 0x49, (byte) 0x4A, (byte) 0x53, (byte) 0x54, (byte) 0x55, (byte) 0x56, (byte) 0x57, (byte) 0x58, (byte) 0x59, (byte) 0x5A, (byte) 0x63, (byte) 0x64, (byte) 0x65, (byte) 0x66, (byte) 0x67, (byte) 0x68, (byte) 0x69, (byte) 0x6A, (byte) 0x73, (byte) 0x74, (byte) 0x75, (byte) 0x76, (byte) 0x77, (byte) 0x78, (byte) 0x79, (byte) 0x7A, (byte) 0x82, (byte) 0x83, (byte) 0x84, (byte) 0x85, (byte) 0x86, (byte) 0x87, (byte) 0x88, (byte) 0x89, (byte) 0x8A, (byte) 0x92, (byte) 0x93, (byte) 0x94, (byte) 0x95, (byte) 0x96, (byte) 0x97, (byte) 0x98, (byte) 0x99, (byte) 0x9A, (byte) 0xA2, (byte) 0xA3, (byte) 0xA4, (byte) 0xA5, (byte) 0xA6, (byte) 0xA7, (byte) 0xA8, (byte) 0xA9, (byte) 0xAA, (byte) 0xB2, (byte) 0xB3, (byte) 0xB4, (byte) 0xB5, (byte) 0xB6, (byte) 0xB7, (byte) 0xB8, (byte) 0xB9, (byte) 0xBA, (byte) 0xC2, (byte) 0xC3, (byte) 0xC4, (byte) 0xC5, (byte) 0xC6, (byte) 0xC7, (byte) 0xC8, (byte) 0xC9, (byte) 0xCA, (byte) 0xD2, (byte) 0xD3, (byte) 0xD4, (byte) 0xD5, (byte) 0xD6, (byte) 0xD7, (byte) 0xD8, (byte) 0xD9, (byte) 0xDA, (byte) 0xE2, (byte) 0xE3, (byte) 0xE4, (byte) 0xE5, (byte) 0xE6, (byte) 0xE7, (byte) 0xE8, (byte) 0xE9, (byte) 0xEA, (byte) 0xF2, (byte) 0xF3, (byte) 0xF4, (byte) 0xF5, (byte) 0xF6, (byte) 0xF7, (byte) 0xF8, (byte) 0xF9, (byte) 0xFA, // Start of Scan (section B.2.3) (byte) 0xFF, (byte) 0xDA, // Marker (byte) 0x00, (byte) 0x0C, // Length of header (byte) 0x03, // Number of image components // Scan 1: use DC/AC huff tables 0/0 (byte) 0x01, (byte) 0x00, // Scan 2: use DC/AC huff tables 1/1 (byte) 0x02, (byte) 0x11, // Scan 3: use DC/AC huff tables 1/1 (byte) 0x03, (byte) 0x11, (byte) 0x00, (byte) 0x3F, (byte) 0x00 // Not used }; // This array represents the default JFIF header for quality = 100 and // size = 640x480, without Huffman tables. The values are adjusted when a // file is generated. private static byte[] jfifNoHuff100Header = { // SOI (byte) 0xFF, (byte) 0xD8, // JFIF header (byte) 0xFF, (byte) 0xE0, // Marker (byte) 0x00, (byte) 0x10, // Length = 16 bytes (byte) 0x4A, (byte) 0x46, (byte) 0x49, (byte) 0x46, // "JFIF" (byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x00, // Start of frame (section B.2.2) (byte) 0xFF, (byte) 0xC0, // Baseline DCT (byte) 0x00, (byte) 0x11, // Length = 17 bytes (byte) 0x08, // Sample precision (byte) 0x01, (byte) 0xE0, // Height (byte) 0x02, (byte) 0x80, // Width (byte) 0x03, // Number of components = 3 // Scan 1: 2:1 horiz, (byte) 1:1 vertical, (byte) use QT 0 (byte) 0x01, (byte) 0x21, (byte) 0x00, // Scan 2: 1:1 horiz, (byte) 1:1 vertical, (byte) use QT 1 (byte) 0x02, (byte) 0x11, (byte) 0x01, // Scan 3: 1:1 horiz, (byte) 1:1 vertical, (byte) use QT 1 (byte) 0x03, (byte) 0x11, (byte) 0x01, // Define Quant table (section B.2.4.1) (byte) 0xFF, (byte) 0xDB, // Marker (byte) 0x00, (byte) 0x84, // Length (both tables) (byte) 0x00, // 8 bit values, (byte) table 0 (byte) 0x10, (byte) 0x0B, (byte) 0x0C, (byte) 0x0E, (byte) 0x0C, (byte) 0x0A, (byte) 0x10, (byte) 0x0E, (byte) 0x0D, (byte) 0x0E, (byte) 0x12, (byte) 0x11, (byte) 0x10, (byte) 0x13, (byte) 0x18, (byte) 0x28, (byte) 0x1A, (byte) 0x18, (byte) 0x16, (byte) 0x16, (byte) 0x18, (byte) 0x31, (byte) 0x23, (byte) 0x25, (byte) 0x1D, (byte) 0x28, (byte) 0x3A, (byte) 0x33, (byte) 0x3D, (byte) 0x3C, (byte) 0x39, (byte) 0x33, (byte) 0x38, (byte) 0x37, (byte) 0x40, (byte) 0x48, (byte) 0x5C, (byte) 0x4E, (byte) 0x40, (byte) 0x44, (byte) 0x57, (byte) 0x45, (byte) 0x37, (byte) 0x38, (byte) 0x50, (byte) 0x6D, (byte) 0x51, (byte) 0x57, (byte) 0x5F, (byte) 0x62, (byte) 0x67, (byte) 0x68, (byte) 0x67, (byte) 0x3E, (byte) 0x4D, (byte) 0x71, (byte) 0x79, (byte) 0x70, (byte) 0x64, (byte) 0x78, (byte) 0x5C, (byte) 0x65, (byte) 0x67, (byte) 0x63, (byte) 0x01, // 8 bit values, (byte) table 1 (byte) 0x11, (byte) 0x12, (byte) 0x12, (byte) 0x18, (byte) 0x15, (byte) 0x18, (byte) 0x2F, (byte) 0x1A, (byte) 0x1A, (byte) 0x2F, (byte) 0x63, (byte) 0x42, (byte) 0x38, (byte) 0x42, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, (byte) 0x63, // Start of Scan (section B.2.3) (byte) 0xFF, (byte) 0xDA, // Marker (byte) 0x00, (byte) 0x0C, // Length of header (byte) 0x03, // Number of image components // Scan 1: use DC/AC huff tables 0/0 (byte) 0x01, (byte) 0x00, // Scan 2: use DC/AC huff tables 1/1 (byte) 0x02, (byte) 0x11, // Scan 3: use DC/AC huff tables 1/1 (byte) 0x03, (byte) 0x11, (byte) 0x00, (byte) 0x3F, (byte) 0x00 // Not used }; private void writeJfifHuffHeader() throws IOException { byte[] newHeader = new byte[jfifHuff100Header.length]; System.arraycopy( jfifHuff100Header, 0, newHeader, 0, jfifHuff100Header.length ); // Set image width in JFIF header. newHeader[27] = (byte) ( ( width >>> 8 ) & 0xff ); newHeader[28] = (byte) ( width & 0xff ); // Set image height in JFIF header. newHeader[25] = (byte) ( ( height >>> 8 ) & 0xff ); newHeader[26] = (byte) ( height & 0xff ); // Adjust the quality factor. // // The default quality factor is 100, therefore if // our quality factor does not equal 100 we must // scale the quantization matrices in the JFIF header. // Note that values are clipped to a max of 255. if ( qfactor != 100 ) { for ( int i = 44; i < 108; ++i ) { int t = ( newHeader[i] * qfactor ) / 100; newHeader[i] = (byte) Math.max( t, 0xff ); } for ( int i = 109; i < 173; ++i ) { int t = ( newHeader[i] * qfactor ) / 100; newHeader[i] = (byte) Math.max( t, 0xff ); } } // Write out buffer. out.write( newHeader ); } private void writeJfifNoHuffHeader() throws IOException { byte[] newHeader = new byte[jfifNoHuff100Header.length]; System.arraycopy( jfifNoHuff100Header, 0, newHeader, 0, jfifNoHuff100Header.length ); // Set image width in JFIF header. newHeader[27] = (byte) ( ( width >>> 8 ) & 0xff ); newHeader[28] = (byte) ( width & 0xff ); // Set image height in JFIF header. newHeader[25] = (byte) ( ( height >>> 8 ) & 0xff ); newHeader[26] = (byte) ( height & 0xff ); // Adjust the quality factor. // // The default quality factor is 100, therefore if // our quality factor does not equal 100 we must // scale the quantization matrices in the JFIF header. // Note that values are clipped to a max of 255. if ( qfactor != 100 ) { for ( int i = 44; i < 108; ++i ) { int t = ( newHeader[i] * qfactor ) / 100; newHeader[i] = (byte) Math.max( t, 0xff ); } for ( int i = 109; i < 173; ++i ) { int t = ( newHeader[i] * qfactor ) / 100; newHeader[i] = (byte) Math.max( t, 0xff ); } } // Write out buffer. out.write( newHeader ); } }