# Executing Baseline Algorithms¶

The first thing you might want to do is to execute one of the vein presentation attack detection algorithms that are implemented in bob.pad.vein.

## Running Baseline Experiments¶

Currently, there is only one available baseline in this package, based on the work from [TREA15], using Fourier Transforms. You can run this baseline and draw comparisons to other results presented on the 1st Competition on Counter Measures to Finger Vein Spoofing Attacks since scores from the competition are included in this package for reproducibility purposes.

To run the baseline experiments, you can use the spoof.py script by just going to the console and typing:

$spoof.py  This script is explained in more detail in Running Presentation Attack Detection Experiments. The spoof.py --help option shows you, which other options you can set. Usually it is a good idea to have at least verbose level 2 (i.e., calling spoof.py --verbose --verbose, or the short version spoof.py -vv). Note Running in Parallel To run the experiments in parallel, you can define an SGE grid or local host (multi-processing) configurations as explained in Running in Parallel. In short, to run in the Idiap SGE grid, you can simply add the --grid command line option, without parameters. To run experiments in parallel on the local machine, simply add a --parallel <N> option, where <N> specifies the number of parallel jobs you want to execute. Database setups and baselines are encoded using Configuration Files, all stored inside the package root, in the directory bob/pad/vein/configurations. Documentation for each resource is available on the section Resources. Warning You cannot run experiments just by executing the command line instructions described in this guide. You need first to procure yourself the raw data files that correspond to each database used here in order to correctly run experiments with those data. Biometric data is considered private data and, under EU regulations, cannot be distributed without a consent or license. You may consult our Databases resources section for checking currently supported databases and accessing download links for the raw data files. Once the raw data files have been downloaded, particular attention should be given to the directory locations of those. Unpack the databases carefully and annotate the root directory where they have been unpacked. Then, carefully read the Databases section of Installation Instructions on how to correctly setup the ~/.bob_bio_databases.txt file. Use the following keywords on the left side of the assignment (see Databases): [YOUR_VERAFINGER_DIRECTORY] = /complete/path/to/verafinger  Notice it is rather important to use the strings as described above, otherwise bob.pad.base will not be able to correctly load your images. Once this step is done, you can proceed with the instructions below. In the remainder of this section we introduce baseline experiments you can readily run with this tool without further configuration. The only baseline examplified in this guide was published in [TREA15]. ### PAD using Fast-Fourier Transform based Features¶ Detailed description at Fast Fourier Transform-based Features. To run the baseline on the VERA fingervein database, using the full protocol, do the following: $ spoof.py verafinger-pad fourier -vv


Tip

If you have more processing cores on your local machine and don’t want to submit your job for SGE execution, you can run it in parallel (using 4 parallel tasks) by adding the options --parallel=4 --nice=10. Before doing so, make sure the package gridtk is properly installed.

Optionally, you may use the parallel resource configuration which already sets the number of parallel jobs to the number of hardware cores you have installed on your machine (as with multiprocessing.cpu_count()) and sets nice=10. For example:

$spoof.py verafinger-pad fourier parallel -vv  To run on the Idiap SGE grid using our stock io-big-48-slots-4G-memory-enabled (see bob.pad.vein.configurations.gridio4g48) configuration, use: $ spoof.py verafinger-pad fourier grid -vv


You may also, optionally, use the configuration resource gridio4g48, which is just an alias of grid in this package.

This command line selects and runs the following implementations for the toolchain:

As the tool runs, you’ll see printouts that show how it advances through preprocessing, feature extraction and presentation attack detection.

To complete the evaluation, run the command bellow, that will output the equal error rate (EER) and plot the detector error trade-off (DET) curve with the performance:

$bob_compute_perf.py --no-plot <path-to>/results/fourier/full/nonorm/scores-{dev,eval} [Min. criterion: EER] Threshold on Development set: 5.340000e-01 | Development | Test -------+----------------+----------------- FMR | 0.000% (0/120) | 0.000% (0/200) FNMR | 0.000% (0/120) | 0.000% (0/200) HTER | 0.000% | 0.000%  If you do the same analysis for the cropped protocol, you should observe the following output: $ bob_compute_perf.py --no-plot <path-to>/results/fourier/cropped/nonorm/scores-{dev,eval}
[Min. criterion: EER] Threshold on Development set: 5.766667e-01
| Development      | Test
-------+------------------+-------------------
FMR  | 24.167% (29/120) | 21.500% (43/200)
FNMR | 24.167% (29/120) | 16.500% (33/200)
HTER | 24.167%          | 19.000%


## Modifying Baseline Experiments¶

It is fairly easy to modify baseline experiments available in this package. To do so, you must copy the configuration files for the given baseline you want to modify, edit them to make the desired changes and run the experiment again.

For example, suppose you’d like to change the protocol on the Vera Fingervein database and use the protocol cropped instead of the default protocol full. First, you identify where the configuration file sits:

$resources.py -tc -p bob.pad.vein - bob.pad.vein X.Y.Z @ /path/to/bob.pad.vein: + verafinger-pad --> bob.pad.vein.configurations.verafinger + fourier --> bob.pad.vein.configurations.fourier  The listing above tells the verafinger configuration file sits on the file /path/to/bob.pad.vein/bob/pad/vein/configurations/verafinger.py. In order to modify it, make a local copy. For example: $ cp /path/to/bob.pad.vein/bob/pad/vein/configurations/verafinger.py verafinger_cropped.py
$# edit verafinger_cropped.py, change the value of "protocol" to "cropped"  Also, don’t forget to change all relative module imports (such as from ..database.verafinger import Database) to absolute imports (e.g. from bob.pad.vein.database.verafinger import Database). This will make the configuration file work irrespectively of its location w.r.t. bob.pad.vein. The final version of the modified file could look like this: from bob.pad.vein.database.verafinger import Database database = Database(original_directory='/where/you/have/the/raw/files', original_extension='.png', #don't change this ) protocol = 'cropped'  Now, re-run the experiment using your modified database descriptor: $ spoof.py ./verafinger_cropped.py fourier -vv


Notice we replace the use of the registered configuration file named verafinger-pad by the local file verafinger_cropped.py. This makes the program spoof.py take that into consideration instead of the original file.