This python package is suitable for working with Planetary Data System (PDS) data products in your own projects.
Several command line tools are also available for viewing labels and image contents as well as image conversion.
PyPDS is a python interface to Planetary Data System (PDS) data products. For more information please visit the PyPDS Wiki and the Sphinx documentation included in the source.
The latest documentation is available on Read the Docs.
- Install PIL
Install PyPDS
From the Python Package Index
pip install PyPDS
Note that starting from pip version >= 1.4 you need to include the --pre(-release) option because of PyPDS' non-standard versioning scheme. So, use:
pip install --pre PyPDS
From the GitHub repository
git clone git://github.com/RyanBalfanz/PyPDS.git
If you want to contribute, consider creating your own fork and submitting a pull request.
First, you may want to run tests.py to verify that things seem to be working. That files was based on the interacitve examples below. There are more examples in the documentation.
Before we may do anything, let's import some modules.
>>> import pprint >>> from pds.core.common import open_pds >>> from pds.core.parser import Parser
If we are to get all the labels from a PDS file, we'll need a Parser object.
>>> parser = Parser()
Now we use use it's parse method on a file. The file should first be opened with open_pds.
>>> labels = parser.parse(open_pds("../test_data/pds.img"))
The return object is just a dictionary. Let's take a look.
>>> pprint.pprint(labels.keys()) # Inspect the top-level labels. ['IMAGE_HISTOGRAM', 'IMAGE_MAP_PROJECTION_CATALOG', 'FILE_RECORDS', 'IMAGE_ID', 'TARGET_NAME', 'SOURCE_IMAGE_ID', 'IMAGE', 'LABEL_RECORDS', 'SPACECRAFT_NAME', 'NOTE', 'RECORD_TYPE', 'CCSD3ZF0000100000001NJPL3IF0PDS200000001', '^IMAGE', 'INSTRUMENT_NAME', '^IMAGE_HISTOGRAM', 'DATA_SET_ID', 'RECORD_BYTES']
Some of the labels contain other labels, which are also dictionary objects.
>>> pprint.pprint(labels["IMAGE"]) # Inspect the image labels. {'CHECKSUM': '12054227', 'LINES': '320', 'LINE_SAMPLES': '306', 'SAMPLE_BITS': '8', 'SAMPLE_BIT_MASK': '2#11111111#', 'SAMPLE_TYPE': 'UNSIGNED_INTEGER'}
PyPDS also takes care of the details about creating image objects. Behind the scenes all images are instances of PIL's Image class.
To get an image from a PDS file, create an ImageExtractor object and use its extract method. Don't forget to first open the PDS file.
>>> from pds.core.common import open_pds >>> from pds.imageextractor import ImageExtractor >>> ie = ImageExtractor() >>> img, labels = ie.extract(open_pds("../test_data/pds.img"))
The extract method first parses the file, then creates the image. Since it goes to the trouble of doing so anyway, it provides the label as a freebie, along with the image.
Here, img is an instance of PIL's Image class. Do whatever you want to it.
>>> print (img.mode, img.size) ('L', (306, 320)) >>> img.show() # Open the image in the default viewer. >>> img.save("pds.img.jpeg") # Write the image to disk in JPEG format.
Verify that the returned image has the proper dimensions.
>>> imageSize = map(int, ... (labels["IMAGE"]["LINE_SAMPLES"], ... labels["IMAGE"]["LINES"])) # Save the image dimensions with integers. >>> tuple(imageSize) == img.size # The built-in map returns a list, but Image.size is a tuple. True
By the way, an Image has a show method which should happily open the image in your default viewer.
Sometimes you might not want to interact with PDS files programmatically. PyPDS also comes with several tools which are handy for working with PDS files at the command line.
Each has several options. For detailed information use --help.
- pds-convert.py
Convert images to the specified format.
- pds-image.py
Like pds-convert.py but dump to standard output.
- pds-labels.py
Dump the labels to standard output.
- pds-view.py
View an image contained in a PDS file in the default viewer.
The MIT License (MIT)
Copyright (c) 2009-2013 Ryan Balfanz
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.