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Diffstat (limited to 'core/exif.h')
| -rw-r--r-- | core/exif.h | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/core/exif.h b/core/exif.h new file mode 100644 index 000000000..0fb3a7d4a --- /dev/null +++ b/core/exif.h @@ -0,0 +1,147 @@ +/************************************************************************** + 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(); + } + + time_t epoch(); +}; + +// 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 // EXIF_H |