/* * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.sun.imageio.plugins.jpeg; import javax.imageio.ImageTypeSpecifier; import javax.imageio.plugins.jpeg.JPEGQTable; import javax.imageio.plugins.jpeg.JPEGHuffmanTable; import java.awt.image.ColorModel; import java.awt.color.ColorSpace; import java.awt.color.ICC_ColorSpace; /** * A class containing JPEG-related constants, definitions, and * static methods. This class and its constants must be public so that * {@code JPEGImageWriteParam} can see it. */ public class JPEG { // List of all the JPEG markers (pre-JPEG2000) /** For temporary use in arithmetic coding */ public static final int TEM = 0x01; // Codes 0x02 - 0xBF are reserved // SOF markers for Nondifferential Huffman coding /** Baseline DCT */ public static final int SOF0 = 0xC0; /** Extended Sequential DCT */ public static final int SOF1 = 0xC1; /** Progressive DCT */ public static final int SOF2 = 0xC2; /** Lossless Sequential */ public static final int SOF3 = 0xC3; /** Define Huffman Tables */ public static final int DHT = 0xC4; // SOF markers for Differential Huffman coding /** Differential Sequential DCT */ public static final int SOF5 = 0xC5; /** Differential Progressive DCT */ public static final int SOF6 = 0xC6; /** Differential Lossless */ public static final int SOF7 = 0xC7; /** Reserved for JPEG extensions */ public static final int JPG = 0xC8; // SOF markers for Nondifferential arithmetic coding /** Extended Sequential DCT, Arithmetic coding */ public static final int SOF9 = 0xC9; /** Progressive DCT, Arithmetic coding */ public static final int SOF10 = 0xCA; /** Lossless Sequential, Arithmetic coding */ public static final int SOF11 = 0xCB; /** Define Arithmetic conditioning tables */ public static final int DAC = 0xCC; // SOF markers for Differential arithmetic coding /** Differential Sequential DCT, Arithmetic coding */ public static final int SOF13 = 0xCD; /** Differential Progressive DCT, Arithmetic coding */ public static final int SOF14 = 0xCE; /** Differential Lossless, Arithmetic coding */ public static final int SOF15 = 0xCF; // Restart Markers public static final int RST0 = 0xD0; public static final int RST1 = 0xD1; public static final int RST2 = 0xD2; public static final int RST3 = 0xD3; public static final int RST4 = 0xD4; public static final int RST5 = 0xD5; public static final int RST6 = 0xD6; public static final int RST7 = 0xD7; /** Number of restart markers */ public static final int RESTART_RANGE = 8; /** Start of Image */ public static final int SOI = 0xD8; /** End of Image */ public static final int EOI = 0xD9; /** Start of Scan */ public static final int SOS = 0xDA; /** Define Quantisation Tables */ public static final int DQT = 0xDB; /** Define Number of lines */ public static final int DNL = 0xDC; /** Define Restart Interval */ public static final int DRI = 0xDD; /** Define Heirarchical progression */ public static final int DHP = 0xDE; /** Expand reference image(s) */ public static final int EXP = 0xDF; // Application markers /** APP0 used by JFIF */ public static final int APP0 = 0xE0; public static final int APP1 = 0xE1; public static final int APP2 = 0xE2; public static final int APP3 = 0xE3; public static final int APP4 = 0xE4; public static final int APP5 = 0xE5; public static final int APP6 = 0xE6; public static final int APP7 = 0xE7; public static final int APP8 = 0xE8; public static final int APP9 = 0xE9; public static final int APP10 = 0xEA; public static final int APP11 = 0xEB; public static final int APP12 = 0xEC; public static final int APP13 = 0xED; /** APP14 used by Adobe */ public static final int APP14 = 0xEE; public static final int APP15 = 0xEF; // codes 0xF0 to 0xFD are reserved /** Comment marker */ public static final int COM = 0xFE; // JFIF Resolution units /** The X and Y units simply indicate the aspect ratio of the pixels. */ public static final int DENSITY_UNIT_ASPECT_RATIO = 0; /** Pixel density is in pixels per inch. */ public static final int DENSITY_UNIT_DOTS_INCH = 1; /** Pixel density is in pixels per centemeter. */ public static final int DENSITY_UNIT_DOTS_CM = 2; /** The max known value for DENSITY_UNIT */ public static final int NUM_DENSITY_UNIT = 3; // Adobe transform values public static final int ADOBE_IMPOSSIBLE = -1; public static final int ADOBE_UNKNOWN = 0; public static final int ADOBE_YCC = 1; public static final int ADOBE_YCCK = 2; // Spi initialization stuff public static final String vendor = "Oracle Corporation"; public static final String version = "0.5"; // Names of the formats we can read or write static final String [] names = {"JPEG", "jpeg", "JPG", "jpg"}; static final String [] suffixes = {"jpg", "jpeg"}; static final String [] MIMETypes = {"image/jpeg"}; public static final String nativeImageMetadataFormatName = "javax_imageio_jpeg_image_1.0"; public static final String nativeImageMetadataFormatClassName = "com.sun.imageio.plugins.jpeg.JPEGImageMetadataFormat"; public static final String nativeStreamMetadataFormatName = "javax_imageio_jpeg_stream_1.0"; public static final String nativeStreamMetadataFormatClassName = "com.sun.imageio.plugins.jpeg.JPEGStreamMetadataFormat"; // IJG Color codes. public static final int JCS_UNKNOWN = 0; // error/unspecified public static final int JCS_GRAYSCALE = 1; // monochrome public static final int JCS_RGB = 2; // red/green/blue public static final int JCS_YCbCr = 3; // Y/Cb/Cr (also known as YUV) public static final int JCS_CMYK = 4; // C/M/Y/K public static final int JCS_YCCK = 5; // Y/Cb/Cr/K public static final int NUM_JCS_CODES = JCS_YCCK+1; /** IJG can handle up to 4-channel JPEGs */ static final int [] [] bandOffsets = {{0}, {0, 1}, {0, 1, 2}, {0, 1, 2, 3}}; static final int [] bOffsRGB = { 2, 1, 0 }; /* These are kept in the inner class to avoid static initialization * of the CMM class until someone actually needs it. * (e.g. do not init CMM on the request for jpeg mime types) */ public static class JCS { public static final ColorSpace sRGB = ColorSpace.getInstance(ColorSpace.CS_sRGB); } // Default value for ImageWriteParam public static final float DEFAULT_QUALITY = 0.75F; /** * Returns {@code true} if the given {@code ColorSpace} * object is an instance of ICC_ColorSpace but is not one of the * standard {@code ColorSpaces} returned by * {@code ColorSpace.getInstance()}. */ static boolean isNonStandardICC(ColorSpace cs) { boolean retval = false; if ((cs instanceof ICC_ColorSpace) && (!cs.isCS_sRGB()) && (!cs.equals(ColorSpace.getInstance(ColorSpace.CS_CIEXYZ))) && (!cs.equals(ColorSpace.getInstance(ColorSpace.CS_GRAY))) && (!cs.equals(ColorSpace.getInstance(ColorSpace.CS_LINEAR_RGB))) && (!cs.equals(ColorSpace.getInstance(ColorSpace.CS_PYCC))) ) { retval = true; } return retval; } /** * Returns {@code true} if the given imageType can be used * in a JFIF file. If {@code input} is true, then the * image type is considered before colorspace conversion. */ static boolean isJFIFcompliant(ImageTypeSpecifier imageType, boolean input) { ColorModel cm = imageType.getColorModel(); // Can't have alpha if (cm.hasAlpha()) { return false; } // Gray is OK, always int numComponents = imageType.getNumComponents(); if (numComponents == 1) { return true; } // If it isn't gray, it must have 3 channels if (numComponents != 3) { return false; } if (input) { // Must be RGB if (cm.getColorSpace().getType() == ColorSpace.TYPE_RGB) { return true; } } else { // Must be YCbCr if (cm.getColorSpace().getType() == ColorSpace.TYPE_YCbCr) { return true; } } return false; } /** * Given an image type, return the Adobe transform corresponding to * that type, or ADOBE_IMPOSSIBLE if the image type is incompatible * with an Adobe marker segment. If {@code input} is true, then * the image type is considered before colorspace conversion. */ static int transformForType(ImageTypeSpecifier imageType, boolean input) { int retval = ADOBE_IMPOSSIBLE; ColorModel cm = imageType.getColorModel(); switch (cm.getColorSpace().getType()) { case ColorSpace.TYPE_GRAY: retval = ADOBE_UNKNOWN; break; case ColorSpace.TYPE_RGB: retval = input ? ADOBE_YCC : ADOBE_UNKNOWN; break; case ColorSpace.TYPE_YCbCr: retval = ADOBE_YCC; break; case ColorSpace.TYPE_CMYK: retval = input ? ADOBE_YCCK : ADOBE_IMPOSSIBLE; } return retval; } /** * Converts an ImageWriteParam (i.e. IJG) non-linear quality value * to a float suitable for passing to JPEGQTable.getScaledInstance(). */ static float convertToLinearQuality(float quality) { // The following is converted from the IJG code. if (quality <= 0.0F) { quality = 0.01F; } if (quality > 1.00F) { quality = 1.00F; } if (quality < 0.5F) { quality = 0.5F / quality; } else { quality = 2.0F - (quality * 2.0F); } return quality; } /** * Return an array of default, visually lossless quantization tables. */ static JPEGQTable [] getDefaultQTables() { JPEGQTable [] qTables = new JPEGQTable[2]; qTables[0] = JPEGQTable.K1Div2Luminance; qTables[1] = JPEGQTable.K2Div2Chrominance; return qTables; } /** * Return an array of default Huffman tables. */ static JPEGHuffmanTable [] getDefaultHuffmanTables(boolean wantDC) { JPEGHuffmanTable [] tables = new JPEGHuffmanTable[2]; if (wantDC) { tables[0] = JPEGHuffmanTable.StdDCLuminance; tables[1] = JPEGHuffmanTable.StdDCChrominance; } else { tables[0] = JPEGHuffmanTable.StdACLuminance; tables[1] = JPEGHuffmanTable.StdACChrominance; } return tables; } }