Metar is a library and command line program for reading image metadata.
You can read metadata from JPEG, DNG and TIFF images. Metar understands the standard image metadata formats: XMP, IPTC, Exif, and Tiff tags.
You can run metar from the command line to display image metadata. Running metar without any parameters shows how to use it. For example:
metar Show metadata information for the given image(s). Usage: metar [-j] [-v] file [file...] -j --json Output JSON data. -v --version Show the version number. -h --help Show this help. file Image filename to analyze.
You pass an image filename and metar outputs metadata to the screen, for example:
metar testfiles/image.dng ========== ifd1 ========== offset = 8 next = 0 NewSubfileType(254) = [1] ImageWidth(256) = [256] ImageHeight(257) = [171] BitsPerSample(258) = [8, 8, 8] Compression(259) = [1] PhotometricInterpretation(262) = [2] Make(271) = ["Canon"] Model(272) = ["Canon EOS 20D"] ...
Only the first few lines are shown in the example above to save space. For this image there are 291 lines:
metar testfiles/image.dng | wc -l 291
You can use the metar python module to read image file metadata in your python programs. It contains four public methods: read_metadata_json, read_metadata, key_name, and get_version.
In a python interactive session you can see the methods:
>>> import metar >>> dir(metar) ['__doc__', '__file__', '__name__', '__package__', 'get_version', 'key_name', 'read_metadata', 'read_metadata_json']
The metar module has help documentation in doc strings.
>>> help(metar)
You can determine the metar version number with the get_version function:
>>> metar.get_version() '0.0.4'
You can read the metadata from jpeg and tiff image files using the read_metadata and read_metadata_json functions.
The read_metadata_json function returns the metadata as a JSON string. You can load that into a python dictionary with the json loads function.
>>> filename = "testfiles/IMG_6093.JPG" >>> string = metar.read_metadata_json(filename) >>> import json >>> metadata = json.loads(string)
Then you can extract the metadata you are interested in from the dictionary.
>>> image = metadata['image']
>>> print('width = %s' % image['width'])
width = 3329
>>> print('height = %s' % image['height'])
height = 2219
The read_metadata function returns a more human readable string.
>>> string = metar.read_metadata(filename) >>> print(string) ========== APP0 ========== id = "JFIF" major = 1 minor = 2 units = 1 x = 240 y = 240 ...
You can learn how to build, test and install on the development page.
- development -- how to build, test and install
You can learn how metar deals with special images with unknown sections or corrupt files and other details on the details page.
- details -- metadata processing details
You can view the documentation for all the modules and procedures on the index page. This documentation is created from embedded doc comments in the source.
- index -- index to source documentation
Here is the metar module dependencies graph:
