com.drew.metadata.adobe.AdobeJpegDirectory Maven / Gradle / Ivy

/*
 * Copyright 2002-2017 Drew Noakes
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 *
 * More information about this project is available at:
 *
 *    https://drewnoakes.com/code/exif/
 *    https://github.com/drewnoakes/metadata-extractor
 */

package com.drew.metadata.adobe;

import com.drew.lang.annotations.NotNull;
import com.drew.metadata.Directory;

import java.util.HashMap;

/**
 * Contains image encoding information for DCT filters, as stored by Adobe.
 */
@SuppressWarnings("WeakerAccess")
public class AdobeJpegDirectory extends Directory {

    public static final int TAG_DCT_ENCODE_VERSION = 0;
    /**
     * The convention for TAG_APP14_FLAGS0 and TAG_APP14_FLAGS1 is that 0 bits are benign.
     * 1 bits in TAG_APP14_FLAGS0 pass information that is possibly useful but not essential for decoding.
     * 
     * 0x8000 bit: Encoder used Blend=1 downsampling
     */
    public static final int TAG_APP14_FLAGS0 = 1;
    /**
     * The convention for TAG_APP14_FLAGS0 and TAG_APP14_FLAGS1 is that 0 bits are benign.
     * 1 bits in TAG_APP14_FLAGS1 pass information essential for decoding. DCTDecode could reject a compressed
     * image, if there are 1 bits in TAG_APP14_FLAGS1 or color transform codes that it cannot interpret.
     */
    public static final int TAG_APP14_FLAGS1 = 2;
    public static final int TAG_COLOR_TRANSFORM = 3;

    private static final HashMap _tagNameMap = new HashMap();

    static {
        _tagNameMap.put(TAG_DCT_ENCODE_VERSION, "DCT Encode Version");
        _tagNameMap.put(TAG_APP14_FLAGS0, "Flags 0");
        _tagNameMap.put(TAG_APP14_FLAGS1, "Flags 1");
        _tagNameMap.put(TAG_COLOR_TRANSFORM, "Color Transform");
    }

    public AdobeJpegDirectory() {
        this.setDescriptor(new AdobeJpegDescriptor(this));
    }

    @NotNull
    @Override
    public String getName() {
        return "Adobe JPEG";
    }

    @NotNull
    @Override
    protected HashMap getTagNameMap() {
        return _tagNameMap;
    }
}