1 /************************************************************************** 2 exif.h -- A simple ISO C++ library to parse basic EXIF 3 information from a JPEG file. 4 5 Based on the description of the EXIF file format at: 6 -- http://park2.wakwak.com/~tsuruzoh/Computer/Digicams/exif-e.html 7 -- http://www.media.mit.edu/pia/Research/deepview/exif.html 8 -- http://www.exif.org/Exif2-2.PDF 9 10 Copyright (c) 2010-2015 Mayank Lahiri 11 mlahiri@gmail.com 12 All rights reserved. 13 14 VERSION HISTORY: 15 ================ 16 17 2.2: Release December 2014 18 -- 19 20 2.1: Released July 2013 21 -- fixed a bug where JPEGs without an EXIF SubIFD would not be parsed 22 -- fixed a bug in parsing GPS coordinate seconds 23 -- fixed makefile bug 24 -- added two pathological test images from Matt Galloway 25 http://www.galloway.me.uk/2012/01/uiimageorientation-exif-orientation-sample-images/ 26 -- split main parsing routine for easier integration into Firefox 27 28 2.0: Released February 2013 29 -- complete rewrite 30 -- no new/delete 31 -- added GPS support 32 33 1.0: Released 2010 34 35 Redistribution and use in source and binary forms, with or without 36 modification, are permitted provided that the following conditions are met: 37 38 -- Redistributions of source code must retain the above copyright notice, 39 this list of conditions and the following disclaimer. 40 -- Redistributions in binary form must reproduce the above copyright notice, 41 this list of conditions and the following disclaimer in the documentation 42 and/or other materials provided with the distribution. 43 44 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY EXPRESS 45 OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 46 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN 47 NO EVENT SHALL THE FREEBSD PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 48 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 49 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 50 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 51 OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 52 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 53 EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 54 */ 55 #ifndef __EXIF_H 56 #define __EXIF_H 57 58 #include <string> 59 60 namespace easyexif { 61 62 // 63 // Class responsible for storing and parsing EXIF information from a JPEG blob 64 // 65 class EXIFInfo { 66 public: 67 // Parsing function for an entire JPEG image buffer. 68 // 69 // PARAM 'data': A pointer to a JPEG image. 70 // PARAM 'length': The length of the JPEG image. 71 // RETURN: PARSE_EXIF_SUCCESS (0) on succes with 'result' filled out 72 // error code otherwise, as defined by the PARSE_EXIF_ERROR_* macros 73 int parseFrom(const unsigned char *data, unsigned length); 74 int parseFrom(const std::string &data); 75 76 // Parsing function for an EXIF segment. This is used internally by parseFrom() 77 // but can be called for special cases where only the EXIF section is 78 // available (i.e., a blob starting with the bytes "Exif\0\0"). 79 int parseFromEXIFSegment(const unsigned char *buf, unsigned len); 80 81 // Set all data members to default values. 82 void clear(); 83 84 // Data fields filled out by parseFrom() 85 char ByteAlign; // 0 = Motorola byte alignment, 1 = Intel 86 std::string ImageDescription; // Image description 87 std::string Make; // Camera manufacturer's name 88 std::string Model; // Camera model 89 unsigned short Orientation; // Image orientation, start of data corresponds to 90 // 0: unspecified in EXIF data 91 // 1: upper left of image 92 // 3: lower right of image 93 // 6: upper right of image 94 // 8: lower left of image 95 // 9: undefined 96 unsigned short BitsPerSample; // Number of bits per component 97 std::string Software; // Software used 98 std::string DateTime; // File change date and time 99 std::string DateTimeOriginal; // Original file date and time (may not exist) 100 std::string DateTimeDigitized; // Digitization date and time (may not exist) 101 std::string SubSecTimeOriginal; // Sub-second time that original picture was taken 102 std::string Copyright; // File copyright information 103 double ExposureTime; // Exposure time in seconds 104 double FNumber; // F/stop 105 unsigned short ISOSpeedRatings; // ISO speed 106 double ShutterSpeedValue; // Shutter speed (reciprocal of exposure time) 107 double ExposureBiasValue; // Exposure bias value in EV 108 double SubjectDistance; // Distance to focus point in meters 109 double FocalLength; // Focal length of lens in millimeters 110 unsigned short FocalLengthIn35mm; // Focal length in 35mm film 111 char Flash; // 0 = no flash, 1 = flash used 112 unsigned short MeteringMode; // Metering mode 113 // 1: average 114 // 2: center weighted average 115 // 3: spot 116 // 4: multi-spot 117 // 5: multi-segment 118 unsigned ImageWidth; // Image width reported in EXIF data 119 unsigned ImageHeight; // Image height reported in EXIF data 120 struct Geolocation_t { // GPS information embedded in file 121 double Latitude; // Image latitude expressed as decimal 122 double Longitude; // Image longitude expressed as decimal 123 double Altitude; // Altitude in meters, relative to sea level 124 char AltitudeRef; // 0 = above sea level, -1 = below sea level 125 double DOP; // GPS degree of precision (DOP) 126 struct Coord_t { 127 double degrees; 128 double minutes; 129 double seconds; 130 char direction; 131 } LatComponents, LonComponents; // Latitude, Longitude expressed in deg/min/sec 132 } GeoLocation; 133 struct LensInfo_t { // Lens information 134 double FStopMin; // Min aperture (f-stop) 135 double FStopMax; // Max aperture (f-stop) 136 double FocalLengthMin; // Min focal length (mm) 137 double FocalLengthMax; // Max focal length (mm) 138 double FocalPlaneXResolution; // Focal plane X-resolution 139 double FocalPlaneYResolution; // Focal plane Y-resolution 140 std::string Make; // Lens manufacturer 141 std::string Model; // Lens model 142 } LensInfo; 143 144 EXIFInfo()145 EXIFInfo() { 146 clear(); 147 } 148 }; 149 150 } 151 152 // Parse was successful 153 #define PARSE_EXIF_SUCCESS 0 154 // No JPEG markers found in buffer, possibly invalid JPEG file 155 #define PARSE_EXIF_ERROR_NO_JPEG 1982 156 // No EXIF header found in JPEG file. 157 #define PARSE_EXIF_ERROR_NO_EXIF 1983 158 // Byte alignment specified in EXIF file was unknown (not Motorola or Intel). 159 #define PARSE_EXIF_ERROR_UNKNOWN_BYTEALIGN 1984 160 // EXIF header was found, but data was corrupted. 161 #define PARSE_EXIF_ERROR_CORRUPT 1985 162 163 #endif 164