/*
* Copyright 2002-2016 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.exif;
import com.drew.lang.GeoLocation;
import com.drew.lang.Rational;
import com.drew.lang.annotations.NotNull;
import com.drew.lang.annotations.Nullable;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Locale;
/**
* Describes Exif tags that contain Global Positioning System (GPS) data.
*
* @author Drew Noakes https://drewnoakes.com
*/
public class GpsDirectory extends ExifDirectoryBase
{
/** GPS tag version GPSVersionID 0 0 BYTE 4 */
public static final int TAG_VERSION_ID = 0x0000;
/** North or South Latitude GPSLatitudeRef 1 1 ASCII 2 */
public static final int TAG_LATITUDE_REF = 0x0001;
/** Latitude GPSLatitude 2 2 RATIONAL 3 */
public static final int TAG_LATITUDE = 0x0002;
/** East or West Longitude GPSLongitudeRef 3 3 ASCII 2 */
public static final int TAG_LONGITUDE_REF = 0x0003;
/** Longitude GPSLongitude 4 4 RATIONAL 3 */
public static final int TAG_LONGITUDE = 0x0004;
/** Altitude reference GPSAltitudeRef 5 5 BYTE 1 */
public static final int TAG_ALTITUDE_REF = 0x0005;
/** Altitude GPSAltitude 6 6 RATIONAL 1 */
public static final int TAG_ALTITUDE = 0x0006;
/** GPS time (atomic clock) GPSTimeStamp 7 7 RATIONAL 3 */
public static final int TAG_TIME_STAMP = 0x0007;
/** GPS satellites used for measurement GPSSatellites 8 8 ASCII Any */
public static final int TAG_SATELLITES = 0x0008;
/** GPS receiver status GPSStatus 9 9 ASCII 2 */
public static final int TAG_STATUS = 0x0009;
/** GPS measurement mode GPSMeasureMode 10 A ASCII 2 */
public static final int TAG_MEASURE_MODE = 0x000A;
/** Measurement precision GPSDOP 11 B RATIONAL 1 */
public static final int TAG_DOP = 0x000B;
/** Speed unit GPSSpeedRef 12 C ASCII 2 */
public static final int TAG_SPEED_REF = 0x000C;
/** Speed of GPS receiver GPSSpeed 13 D RATIONAL 1 */
public static final int TAG_SPEED = 0x000D;
/** Reference for direction of movement GPSTrackRef 14 E ASCII 2 */
public static final int TAG_TRACK_REF = 0x000E;
/** Direction of movement GPSTrack 15 F RATIONAL 1 */
public static final int TAG_TRACK = 0x000F;
/** Reference for direction of image GPSImgDirectionRef 16 10 ASCII 2 */
public static final int TAG_IMG_DIRECTION_REF = 0x0010;
/** Direction of image GPSImgDirection 17 11 RATIONAL 1 */
public static final int TAG_IMG_DIRECTION = 0x0011;
/** Geodetic survey data used GPSMapDatum 18 12 ASCII Any */
public static final int TAG_MAP_DATUM = 0x0012;
/** Reference for latitude of destination GPSDestLatitudeRef 19 13 ASCII 2 */
public static final int TAG_DEST_LATITUDE_REF = 0x0013;
/** Latitude of destination GPSDestLatitude 20 14 RATIONAL 3 */
public static final int TAG_DEST_LATITUDE = 0x0014;
/** Reference for longitude of destination GPSDestLongitudeRef 21 15 ASCII 2 */
public static final int TAG_DEST_LONGITUDE_REF = 0x0015;
/** Longitude of destination GPSDestLongitude 22 16 RATIONAL 3 */
public static final int TAG_DEST_LONGITUDE = 0x0016;
/** Reference for bearing of destination GPSDestBearingRef 23 17 ASCII 2 */
public static final int TAG_DEST_BEARING_REF = 0x0017;
/** Bearing of destination GPSDestBearing 24 18 RATIONAL 1 */
public static final int TAG_DEST_BEARING = 0x0018;
/** Reference for distance to destination GPSDestDistanceRef 25 19 ASCII 2 */
public static final int TAG_DEST_DISTANCE_REF = 0x0019;
/** Distance to destination GPSDestDistance 26 1A RATIONAL 1 */
public static final int TAG_DEST_DISTANCE = 0x001A;
/** Values of "GPS", "CELLID", "WLAN" or "MANUAL" by the EXIF spec. */
public static final int TAG_PROCESSING_METHOD = 0x001B;
public static final int TAG_AREA_INFORMATION = 0x001C;
public static final int TAG_DATE_STAMP = 0x001D;
public static final int TAG_DIFFERENTIAL = 0x001E;
@NotNull
protected static final HashMap<Integer, String> _tagNameMap = new HashMap<Integer, String>();
static
{
addExifTagNames(_tagNameMap);
_tagNameMap.put(TAG_VERSION_ID, "GPS Version ID");
_tagNameMap.put(TAG_LATITUDE_REF, "GPS Latitude Ref");
_tagNameMap.put(TAG_LATITUDE, "GPS Latitude");
_tagNameMap.put(TAG_LONGITUDE_REF, "GPS Longitude Ref");
_tagNameMap.put(TAG_LONGITUDE, "GPS Longitude");
_tagNameMap.put(TAG_ALTITUDE_REF, "GPS Altitude Ref");
_tagNameMap.put(TAG_ALTITUDE, "GPS Altitude");
_tagNameMap.put(TAG_TIME_STAMP, "GPS Time-Stamp");
_tagNameMap.put(TAG_SATELLITES, "GPS Satellites");
_tagNameMap.put(TAG_STATUS, "GPS Status");
_tagNameMap.put(TAG_MEASURE_MODE, "GPS Measure Mode");
_tagNameMap.put(TAG_DOP, "GPS DOP");
_tagNameMap.put(TAG_SPEED_REF, "GPS Speed Ref");
_tagNameMap.put(TAG_SPEED, "GPS Speed");
_tagNameMap.put(TAG_TRACK_REF, "GPS Track Ref");
_tagNameMap.put(TAG_TRACK, "GPS Track");
_tagNameMap.put(TAG_IMG_DIRECTION_REF, "GPS Img Direction Ref");
_tagNameMap.put(TAG_IMG_DIRECTION, "GPS Img Direction");
_tagNameMap.put(TAG_MAP_DATUM, "GPS Map Datum");
_tagNameMap.put(TAG_DEST_LATITUDE_REF, "GPS Dest Latitude Ref");
_tagNameMap.put(TAG_DEST_LATITUDE, "GPS Dest Latitude");
_tagNameMap.put(TAG_DEST_LONGITUDE_REF, "GPS Dest Longitude Ref");
_tagNameMap.put(TAG_DEST_LONGITUDE, "GPS Dest Longitude");
_tagNameMap.put(TAG_DEST_BEARING_REF, "GPS Dest Bearing Ref");
_tagNameMap.put(TAG_DEST_BEARING, "GPS Dest Bearing");
_tagNameMap.put(TAG_DEST_DISTANCE_REF, "GPS Dest Distance Ref");
_tagNameMap.put(TAG_DEST_DISTANCE, "GPS Dest Distance");
_tagNameMap.put(TAG_PROCESSING_METHOD, "GPS Processing Method");
_tagNameMap.put(TAG_AREA_INFORMATION, "GPS Area Information");
_tagNameMap.put(TAG_DATE_STAMP, "GPS Date Stamp");
_tagNameMap.put(TAG_DIFFERENTIAL, "GPS Differential");
}
public GpsDirectory()
{
this.setDescriptor(new GpsDescriptor(this));
}
@Override
@NotNull
public String getName()
{
return "GPS";
}
@Override
@NotNull
protected HashMap<Integer, String> getTagNameMap()
{
return _tagNameMap;
}
/**
* Parses various tags in an attempt to obtain a single object representing the latitude and longitude
* at which this image was captured.
*
* @return The geographical location of this image, if possible, otherwise null
*/
@Nullable
public GeoLocation getGeoLocation()
{
Rational[] latitudes = getRationalArray(TAG_LATITUDE);
Rational[] longitudes = getRationalArray(TAG_LONGITUDE);
String latitudeRef = getString(TAG_LATITUDE_REF);
String longitudeRef = getString(TAG_LONGITUDE_REF);
// Make sure we have the required values
if (latitudes == null || latitudes.length != 3)
return null;
if (longitudes == null || longitudes.length != 3)
return null;
if (latitudeRef == null || longitudeRef == null)
return null;
Double lat = GeoLocation.degreesMinutesSecondsToDecimal(latitudes[0], latitudes[1], latitudes[2], latitudeRef.equalsIgnoreCase("S"));
Double lon = GeoLocation.degreesMinutesSecondsToDecimal(longitudes[0], longitudes[1], longitudes[2], longitudeRef.equalsIgnoreCase("W"));
// This can return null, in cases where the conversion was not possible
if (lat == null || lon == null)
return null;
return new GeoLocation(lat, lon);
}
/**
* Parses the date stamp tag and the time stamp tag to obtain a single Date object representing the
* date and time when this image was captured.
*
* @return A Date object representing when this image was captured, if possible, otherwise null
*/
@Nullable
public Date getGpsDate()
{
String date = getString(TAG_DATE_STAMP);
Rational[] timeComponents = getRationalArray(TAG_TIME_STAMP);
// Make sure we have the required values
if (date == null)
return null;
if (timeComponents == null || timeComponents.length != 3)
return null;
String dateTime = String.format(Locale.US, "%s %02d:%02d:%02.3f UTC",
date, timeComponents[0].intValue(), timeComponents[1].intValue(), timeComponents[2].doubleValue());
try {
DateFormat parser = new SimpleDateFormat("yyyy:MM:dd HH:mm:ss.S z");
return parser.parse(dateTime);
} catch (ParseException e) {
return null;
}
}
}