Python implementation of FALCON: Feedback Adaptive Loop for Content-Based Retrieval
halcon (falcon in Spanish) is a python implementation of the Feedback Adaptive Loop for Content-Based Retrieval (FALCON) algorithm as described in
- Leejay Wu, Christos Faloutsos, Katia P. Sycara, and Terry R. Payne. 2000. FALCON: Feedback Adaptive Loop for Content-Based Retrieval. In Proceedings of the 26th International Conference on Very Large Data Bases (VLDB ‘00), Amr El Abbadi, Michael L. Brodie, Sharma Chakravarthy, Umeshwar Dayal, Nabil Kamel, Gunter Schlageter, and Kyu-Young Whang (Eds.). Morgan Kaufmann Publishers Inc., San Francisco, CA, USA, 297-306.
FALCON is, as described in the article abstract, “a novel method that is designed to handle disjunctive queries within metric spaces. The user provides weights for positive examples; our system ‘learns’ the implied concept and returns similar objects.”
Master branch status
To install the prerequisites in Ubuntu
sudo apt-get install update sudo apt-get install python-numpy python-scipy sudo easy_install pip sudo pip install mpmath
There are several ways to install halcon. The most common way is to download the source code, unzip/untar the source code package and run the command
sudo python setup.py install
I have plans of submitting this package to the Python Package Index. If I do so, then should be able to install it by running the command
sudo pip install halcon
If you wish to install halcon in a virtual enviroment from source code, then you can do
virtualenv halcon cd falcon source ./bin/activate pip install numpy pip install scipy pip install npmath mkdir src cd src git clone email@example.com:icaoberg/falcon.git cd falcon python setup.py install cd ../../ deactivate
If you wish to install halcon in a virtual enviroment from [PyPI](https://pypi.python.org/pypi/halcon), then you can do
virtualenv halcon cd falcon source ./bin/activate pip install numpy pip install scipy pip install npmath pip install halcon deactivate
COMMENT: The previous snippet assumes that you have virtualenv installed in your working system.
There is only one method that you need to know about
halcon.search.query(good_set, candidates, alpha=-5, metric='euclidean', normalization='zscore', debug=False)
Here is a brief description of each of the input arguments
- good_set and candidates are two lists of lists where each member of both lists has the same shape.
record = [<identifier>, <initial_score>, <feature_vector>]
For example in wine.py, I download a CSV file where the first feature_vector looks like this
and then I modify it like this
good_set =  identifier = 'wine00' initial_score = 1 feature_vector = [1,14.23,1.71,2.43,15.6,127,2.8,3.06,.28,2.29,5.64,1.04,3.92,1065] good_set.append([identifier, initial_score, feature_vector])
For more information about the definition of the initial score, please refer to the article. In all my examples I use a initial score of 1, that is, all images have the same weight. The identifier should be unique (though not enforced), so you can tell images apart. This package assumes every object is represented by a feature vector. Feature calculation goes beyond the scope of this package. There are many feature calculation/machine learning packages out there that you might find useful, like OpenCV, mahotas and SLIC.
- alpha. For more information about alpha, please refer to the article. The recommended value by the paper is -5, which is the default value used in this package.
- metric. In the research article, a measure of distance d is used to calculate the distance between two feature vectors. The default value is euclidean (Euclidean distance) and other supported metrics are cityblock (Manhattan distance) and hamming (Hamming distance).
- normalization. Feature normalization option. Default is zscore. Alternative option is standard.
- debug. If debug flag is on, then it should print more information about the calculation as they happen.
For convenience and testing I included some examples. These examples download some datasets from the web and use them to trigger a query. The only exception is the random feature vectors example. For example, to run the iris example simply run in terminal
The examples have a dependency that the package does not, since I use tabulate to pretty print the results from the examples.
virtualenv halcon --system-site-packages . ./halcon/bin/activate cd halcon mkdir src cd src pip install numpy pip install scipy pip install tabulate git clone https://github.com/icaoberg/halcon.git cd halcon python setup.py install cd .. python examples/iris.py
$ python examples/iris.py This example uses the iris dataset from Machine Learning Repository Center for Machine Learning and Intelligent Systems http://archive.ics.uci.edu/ml/datasets/Iris I will use the first feature vector as my query image [[0, 1, array([ 5.1, 3.5, 1.4, 0.2, 1. ])]] And I will use the rest of the feature vectors to find the most similar images Now notice that feature vector with iid1 has the same values iid0 [1, 1, array([ 5.1, 3.5, 1.4, 0.2, 1. ])] So I expect that if halcon is working correctly, then iid1 should be the top hit! Elapsed time: 0.0221660137177 seconds Ranking Identifier Class Score --------- ------------ --------------- ----------- 0 1 Iris-setosa 0 1 28 Iris-setosa 1.27788e-43 2 5 Iris-setosa 2.40121e-40 3 29 Iris-setosa 2.40121e-40 4 40 Iris-setosa 5.83391e-40 5 8 Iris-setosa 7.04398e-39 6 18 Iris-setosa 1.1259e-35 7 41 Iris-setosa 1.51906e-34 8 50 Iris-versicolor 6.99696e-34 9 37 Iris-setosa 1.09221e-32 10 12 Iris-setosa 1.22203e-32 11 49 Iris-setosa 2.05046e-32 12 11 Iris-setosa 4.25801e-31 13 21 Iris-setosa 6.55842e-31 14 47 Iris-setosa 5.54098e-29 15 36 Iris-setosa 7.93943e-29 16 7 Iris-setosa 2.16985e-28 17 20 Iris-setosa 4.23544e-28 18 25 Iris-setosa 1.67453e-27 19 3 Iris-setosa 2.40919e-27 Do the top results in the list above belong to the same class as the query image? If so, then SCORE! It seems to work.
$ python examples/wine.py This example uses the wine dataset from Machine Learning Repository Center for Machine Learning and Intelligent Systems http://archive.ics.uci.edu/ml/datasets/Wine I will use the first three feature vectors as my query wine set And I will use the rest of the feature vectors to find the most similar images Elapsed time: 0.0280928611755 seconds Ranking Identifier Score --------- ------------ ----------- 0 wine1 0 1 wine2 0 2 wine3 0 3 wine21 2.77663e-05 4 wine30 0.000629879 5 wine23 0.00252617 6 wine49 0.00318536 7 wine57 0.00456123 8 wine36 0.0152067 9 wine39 0.0197516 10 wine58 0.0243848 11 wine9 0.024467 12 wine55 0.045762 13 wine24 0.046893 14 wine7 0.113906 15 wine45 0.188355 16 wine27 0.201802 17 wine41 0.206469 18 wine31 0.288536 19 wine56 0.291853
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cd docs make html
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cd docs make latexpdf
To generate epub document
cd docs make epub