EquiFace-2.0

EquiFace is a fairness benchmarking tool for biometric models used in facial verification. It requires just two inputs, the model in a .tflite format, and a testing dataset in the following format:

.
└── Testing Dataset/
    ├── Group A/
    │   ├── ID_1/
    │   │   ├── img_1
    │   │   ├── img_2
    │   │   ├── ...
    │   │   └── img_k
    │   ├── ID_2/
    │   │   ├── img_1
    │   │   ├── img_2
    │   │   ├── ...
    │   │   └── img_k
    │   ├── ...
    │   └── ID_n
    ├── Group B/
    │   ├── ID_1/
    │   │   ├── img_1
    │   │   ├── img_2
    │   │   ├── ...
    │   │   └── img_k
    │   ├── ID_2/
    │   │   ├── img_1
    │   │   ├── img_2
    │   │   ├── ...
    │   │   └── img_k
    │   ├── ...
    │   └── ID_n
    ├── ...
    └── Group Z

Where there are A-Z groups (such as skin tone or ethnic groups), each containing n individuals, and k images per individual.

The False Negative Rate (FNR) is calculated by taking an input pair from each ID (e.g. img_1 and img_2), then computing the cosine similarity between the embeddings. A false positive occurs when an input pair is not verified for a particular ID. This is done for all input pairs, for all IDs in each group.

The False Positive Rate (FPR) is calculated similarily, except input pairs are now images of one ID with another.

Example usage

Installation

pip install equiface==0.1.1

Calculating FPRs and FNRs

# Imports
from equiface.verification import FPR, FNR

# Directories and parameters
dataset_dir = 'testing_dataset/group_1'
model_path = 'model.tflite'
image_size = (160,160) # Input dimension for model
threshold = 0.5 # Threshold for cosine similarity

# FNR
FNR(dataset_dir,
    model_path,
    image_size=image_size,
    threshold=threshold,
    percentage=100,
    use_multiprocessing=True,
    num_cores=4)

FPR(dataset_dir,
    model_path,
    image_size=image_size,
    threshold=threshold,
    percentage=100,
    use_multiprocessing=True,
    num_cores=4)

The results are saved into a YAML file:

- False Negatives: 67
  dataset: testing_dataset/group_1
  metric: FNR
  model_name: model
  num_selected: 1251
  total_pairs: 2502
  value: 0.0536
- False Positives: 699
  dataset: testing_dataset/group_1
  metric: FPR
  model_name: model
  num_selected: 1563
  total_pairs: 3126249
  value: 0.4472

We also provide templates for converting TensorFlow models into the TFLite format, using model architecture and weights provided by DeepFace [1].

[1] S. Serengil and A. Ozpinar, "A Benchmark of Facial Recognition Pipelines and Co-Usability Performances of Modules", Journal of Information Technologies, vol. 17, no. 2, pp. 95-107, 2024.