1. Biometric Quality Evaluation¶
This manual describes the parameters considered for evaluating the quality of a biometric extraction.
The quality evaluation is performed during the template extraction process. This procedure aims to define the best images to be used in a biometric comparison operation.
Each biometric modality has its different evaluation criteria. Below, the criteria for evaluating face images and fingerprints will be discussed.
1.1. Fingerprint Image Evaluation¶
The evaluated parameter list for a fingerprint is:
- Image size;
- Minutiae number;
- High confidence minutiae number;
- Minutiae number above joint;
- Contrast;
- Finger orientation;
- Fingerprint section loss (by scanner margin);
- Finger Area;
- Finger Extension;
- NFIQ value.
1.2. Face Image Evaluation¶
The evaluated parameter list for a face image is:
- Image size;
- Numbers of detected faces;
- Eye position;
- ICAO head format compliance;
- Background uniformity;
- Sharpness;
- Gray level;
- Face orientation;
- Face rotation;
- Open mouth or smile;
- Face obstruction;
- Background color.