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/**************************************************************************
exif.h -- A simple ISO C++ library to parse basic EXIF
information from a JPEG file.
Based on the description of the EXIF file format at:
-- http://park2.wakwak.com/~tsuruzoh/Computer/Digicams/exif-e.html
-- http://www.media.mit.edu/pia/Research/deepview/exif.html
-- http://www.exif.org/Exif2-2.PDF
Copyright (c) 2010-2013 Mayank Lahiri
mlahiri@gmail.com
All rights reserved.
VERSION HISTORY:
================
2.1: Released July 2013
-- fixed a bug where JPEGs without an EXIF SubIFD would not be parsed
-- fixed a bug in parsing GPS coordinate seconds
-- fixed makefile bug
-- added two pathological test images from Matt Galloway
http://www.galloway.me.uk/2012/01/uiimageorientation-exif-orientation-sample-images/
-- split main parsing routine for easier integration into Firefox
2.0: Released February 2013
-- complete rewrite
-- no new/delete
-- added GPS support
1.0: Released 2010
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
-- Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
-- 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 COPYRIGHT HOLDERS ``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 FREEBSD PROJECT 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.
*/
#ifndef __EXIF_H
#define __EXIF_H
#include <string>
//
// Class responsible for storing and parsing EXIF information from a JPEG blob
//
class EXIFInfo {
public:
// Parsing function for an entire JPEG image buffer.
//
// PARAM 'data': A pointer to a JPEG image.
// PARAM 'length': The length of the JPEG image.
// RETURN: PARSE_EXIF_SUCCESS (0) on succes with 'result' filled out
// error code otherwise, as defined by the PARSE_EXIF_ERROR_* macros
int parseFrom(const unsigned char *data, unsigned length);
int parseFrom(const std::string &data);
// Parsing function for an EXIF segment. This is used internally by parseFrom()
// but can be called for special cases where only the EXIF section is
// available (i.e., a blob starting with the bytes "Exif\0\0").
int parseFromEXIFSegment(const unsigned char *buf, unsigned len);
// Set all data members to default values.
void clear();
// Data fields filled out by parseFrom()
char ByteAlign; // 0 = Motorola byte alignment, 1 = Intel
std::string ImageDescription; // Image description
std::string Make; // Camera manufacturer's name
std::string Model; // Camera model
unsigned short Orientation; // Image orientation, start of data corresponds to
// 0: unspecified in EXIF data
// 1: upper left of image
// 3: lower right of image
// 6: upper right of image
// 8: lower left of image
// 9: undefined
unsigned short BitsPerSample; // Number of bits per component
std::string Software; // Software used
std::string DateTime; // File change date and time
std::string DateTimeOriginal; // Original file date and time (may not exist)
std::string DateTimeDigitized; // Digitization date and time (may not exist)
std::string SubSecTimeOriginal; // Sub-second time that original picture was taken
std::string Copyright; // File copyright information
double ExposureTime; // Exposure time in seconds
double FNumber; // F/stop
unsigned short ISOSpeedRatings; // ISO speed
double ShutterSpeedValue; // Shutter speed (reciprocal of exposure time)
double ExposureBiasValue; // Exposure bias value in EV
double SubjectDistance; // Distance to focus point in meters
double FocalLength; // Focal length of lens in millimeters
unsigned short FocalLengthIn35mm; // Focal length in 35mm film
char Flash; // 0 = no flash, 1 = flash used
unsigned short MeteringMode; // Metering mode
// 1: average
// 2: center weighted average
// 3: spot
// 4: multi-spot
// 5: multi-segment
unsigned ImageWidth; // Image width reported in EXIF data
unsigned ImageHeight; // Image height reported in EXIF data
struct Geolocation_t { // GPS information embedded in file
double Latitude; // Image latitude expressed as decimal
double Longitude; // Image longitude expressed as decimal
double Altitude; // Altitude in meters, relative to sea level
char AltitudeRef; // 0 = above sea level, -1 = below sea level
struct Coord_t {
double degrees;
double minutes;
double seconds;
char direction;
} LatComponents, LonComponents; // Latitude, Longitude expressed in deg/min/sec
} GeoLocation;
EXIFInfo() {
clear();
}
};
// Parse was successful
#define PARSE_EXIF_SUCCESS 0
// No JPEG markers found in buffer, possibly invalid JPEG file
#define PARSE_EXIF_ERROR_NO_JPEG 1982
// No EXIF header found in JPEG file.
#define PARSE_EXIF_ERROR_NO_EXIF 1983
// Byte alignment specified in EXIF file was unknown (not Motorola or Intel).
#define PARSE_EXIF_ERROR_UNKNOWN_BYTEALIGN 1984
// EXIF header was found, but data was corrupted.
#define PARSE_EXIF_ERROR_CORRUPT 1985
#endif
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