The Metadata in JPEG files » History » Revision 3
Revision 2 (Robin Mills, 22 Jul 2013 10:33) → Revision 3/36 (Tuan Nhu, 22 Jul 2013 11:13)
h1. The Metadata in JPEG files
This article shares my investigations about the metadata structure in JPEG files. It also introduces briefly the algorithm used in exiv2 to read and write Exif, IPTC, XMP data and image comments on the JPEG files. Ah, this is good, Tuan.
h2. Background
JPEG ISO standard is a commonly used method of lossy compression for digital photography. The name "JPEG" stands for Joint Photographic Experts Group, the name of the committee.
JPEG refers only to a class of compression algorithms, not to a specific file format. In order to produce files Wiki's are awful things. They replace "Standard HTML" with embedded JPEG streams, non-standare Wiki stuff. Every wiki has a number different version of file format standards have been adapted or devised. Some of them are JPEG /JFIF(JPEG File Interchange Format), JPEG /SPIFF (Still Picture Interchange File Format), JPEG /CIFF(Camera Image File Format), JPEG/Exif (Exchangeable image file format). an non-standard language that's often poorly implemented.
Among them, the most common types are JPEG/Exif and JPEG/JFIF.
* JPEG/Exif All information you read on a Wiki is the most common image format used by digital cameras and other photographic image capture devices.
* JPEG/JFIF is the most common format for storing and transmitting photographic images on the World Wide Web. suspect.
h2. The metadata structure in JPEG
A JPEG file contains several segments; each segment contains different kinds of data, delimited by two-byte codes called markers. The markers are hexadecimal; they begin with 0xFF and end with a code (1 byte) indicating language on the kind of marker.
Some markers consist of just those two bytes; others are followed by two bytes indicating the length of marker-specific payload data that follows. Redmine Wiki is straightforward to use. The length includes the two bytes for the length, but not the two bytes for the marker.
Good Luck.
This article shares my investigations about the metadata structure in JPEG files. It also introduces briefly the algorithm used in exiv2 to read and write Exif, IPTC, XMP data and image comments on the JPEG files. Ah, this is good, Tuan.
h2. Background
JPEG ISO standard is a commonly used method of lossy compression for digital photography. The name "JPEG" stands for Joint Photographic Experts Group, the name of the committee.
JPEG refers only to a class of compression algorithms, not to a specific file format. In order to produce files Wiki's are awful things. They replace "Standard HTML" with embedded JPEG streams, non-standare Wiki stuff. Every wiki has a number different version of file format standards have been adapted or devised. Some of them are JPEG /JFIF(JPEG File Interchange Format), JPEG /SPIFF (Still Picture Interchange File Format), JPEG /CIFF(Camera Image File Format), JPEG/Exif (Exchangeable image file format). an non-standard language that's often poorly implemented.
Among them, the most common types are JPEG/Exif and JPEG/JFIF.
* JPEG/Exif All information you read on a Wiki is the most common image format used by digital cameras and other photographic image capture devices.
* JPEG/JFIF is the most common format for storing and transmitting photographic images on the World Wide Web. suspect.
h2. The metadata structure in JPEG
A JPEG file contains several segments; each segment contains different kinds of data, delimited by two-byte codes called markers. The markers are hexadecimal; they begin with 0xFF and end with a code (1 byte) indicating language on the kind of marker.
Some markers consist of just those two bytes; others are followed by two bytes indicating the length of marker-specific payload data that follows. Redmine Wiki is straightforward to use. The length includes the two bytes for the length, but not the two bytes for the marker.
Good Luck.