001/* ***** BEGIN LICENSE BLOCK *****
002 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
003 *
004 * The contents of this file are subject to the Mozilla Public License Version
005 * 1.1 (the "License"); you may not use this file except in compliance with
006 * the License. You may obtain a copy of the License at
007 * http://www.mozilla.org/MPL/
008 *
009 * Software distributed under the License is distributed on an "AS IS" basis,
010 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
011 * for the specific language governing rights and limitations under the
012 * License.
013 *
014 * The Original Code is part of dcm4che, an implementation of DICOM(TM) in
015 * Java(TM), hosted at https://github.com/gunterze/dcm4che.
016 *
017 * The Initial Developer of the Original Code is
018 * Agfa Healthcare.
019 * Portions created by the Initial Developer are Copyright (C) 2013
020 * the Initial Developer. All Rights Reserved.
021 *
022 * Contributor(s):
023 * See @authors listed below
024 *
025 * Alternatively, the contents of this file may be used under the terms of
026 * either the GNU General Public License Version 2 or later (the "GPL"), or
027 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
028 * in which case the provisions of the GPL or the LGPL are applicable instead
029 * of those above. If you wish to allow use of your version of this file only
030 * under the terms of either the GPL or the LGPL, and not to allow others to
031 * use your version of this file under the terms of the MPL, indicate your
032 * decision by deleting the provisions above and replace them with the notice
033 * and other provisions required by the GPL or the LGPL. If you do not delete
034 * the provisions above, a recipient may use your version of this file under
035 * the terms of any one of the MPL, the GPL or the LGPL.
036 *
037 * ***** END LICENSE BLOCK ***** */
038
039package org.dcm4che3.imageio.codec.jpeg;
040
041import org.dcm4che3.util.ByteUtils;
042
043/**
044 * @author Gunter Zeilinger <gunterze@gmail.com>
045 *
046 */
047public class SOFSegment {
048
049    private final byte[] data;
050    private final int offset;
051    private final int numComponents;
052
053    public SOFSegment(byte[] data, int offset) {
054        this.data = data;
055        this.offset = offset;
056        this.numComponents = data[offset+8] & 255;
057        getQTableSelector(numComponents-1);
058    }
059
060    public int offset() {
061        return offset;
062    }
063
064    public int getMarker() {
065        return data[offset] & 255;
066    }
067
068    public int getHeaderLength() {
069        return ByteUtils.bytesToUShortBE(data, offset+1);
070    }
071
072    public int getPrecision() {
073        return data[offset+3] & 255;
074    }
075
076    public int getY() {
077        return ByteUtils.bytesToUShortBE(data, offset+4);
078    }
079
080    public int getX() {
081        return ByteUtils.bytesToUShortBE(data, offset+6);
082    }
083
084    public int getNumComponents() {
085        return numComponents;
086    }
087
088    public int getComponentID(int index) {
089        return data[offset+9+index*3] & 255;
090    }
091
092    public int getXSubsampling(int index) {
093        return (data[offset+10+index*3]>>4) & 15;
094    }
095
096    public int getYSubsampling(int index) {
097        return (data[offset+10+index*3]) & 15;
098    }
099
100    public int getQTableSelector(int index) {
101        return data[offset+11+index*3] & 255;
102    }
103
104    @Override
105    public String toString() {
106        StringBuilder sb = new StringBuilder();
107        sb.append("SOF").append(getMarker()-0xC0)
108          .append("[Lf=").append(getHeaderLength())
109          .append(", P=").append(getPrecision())
110          .append(", Y=").append(getY())
111          .append(", X=").append(getX())
112          .append(", Nf=").append(numComponents);
113        for (int i = 0; i < numComponents; i++) {
114            sb.append(", C").append(i+1).append('=').append(getComponentID(i))
115              .append(", H").append(i+1).append('=').append(getXSubsampling(i))
116              .append(", V").append(i+1).append('=').append(getYSubsampling(i))
117              .append(", Tq").append(i+1).append('=').append(getQTableSelector(i));
118        }
119        sb.append(']');
120        return sb.toString();
121    }
122}