Biometric security systems use biometric data with advanced recognition technology to develop lock and capture mechanisms and limit access to specified data [
1]. The main purpose here is the identification and verification of a person’s identity through his physiological or behavioral biometrics such as the face, iris, fingerprint, etc. [
2]. One of the fast-growing, relatively new, biometrics is the palmprint [
3].The palm is the inner surface of the hand between the wrist and the fingers [
4]. Palmprint refers to an impression of the palm on a surface. A palmprint contains rich intrinsic features, including the principal lines and wrinkles (figure 1) [
1] [
5] [
6] and abundant ridge and minutiae-based features similar to a fingerprint [
3].These significant features make a palmprint very useful in the field of biometrics because these palmprint features have the potential to achieve high accuracy and reliable performance for personal verification and identification [
4,
8]. Many techniques have been proposed for palmprint recognition using minutiae-based features, geometry-based features, transformed-based features, [
7] and more. To process these features many image processing methods such as i) encoding-based algorithm, ii) structure-based methods, iii) statistics-based methods exist [
9]. Recently, most methods in the literature consider Deep Learning due to its high recognition accuracy and the capability to adapt to biometric. samples captured in heterogeneous and less-constrained conditions [
8]. Current state-of-the-art palmprint recognition systems rely on large datasets. The National Institute of Standards and Technology (NIST) recently discontinued several publicly available datasets from its catalog due to privacy issues [
10]– [
13]. To overcome the scarcity of data, we have produced synthetic palmprints. One of the main reasons to generate synthetic images is low cost, high efficiency, and testing privacy. Moreover, the quality and resolution of images generated by generative adversarial networks (GANs) have experienced significant advancements recently [
7,
8,
9]. The architecture of a standard GAN generator operates in a similar fashion: initially, it creates rough, low-resolution attributes that are progressively refined through upsampling layers. These features are then blended locally using convolution layers, and additional intricacies are added via nonlinear processes. However, it's noted that despite these apparent similarities, contemporary GAN structures don't generate images in a naturally hierarchical way. While the broader features primarily dictate the existence of finer details, they don't precisely determine their locations. Instead, it seems that a significant portion of the finer details is established in fixed pixel coordinates. Researchers do not need to depend on real-world data; they can work on synthetic data [
14]. A generator model was learned over training images to generate a synthetic image. In this scenario, synthetic data has the edge over real data regarding enrollment, detection, and verification [
15]. A huge number of synthetic datasets can be produced at low cost and with little effort while posing no privacy risk. A single synthetic image with well-controlled modifications can also be used to alter and expand the dataset. The traditional method to develop synthetic images is by changing the orientation of images and using some filters such as the Gabor filter which changes the final structure for any image [
4,
10,
11]. In the biometric field, the classical approach of developing synthetic images refers to changing the orientation of the fingerprint or changing the skin color for the facial biometric [
12,
13]. There is no traditional approach to generate synthetic palmprints [
16,
17]. Additionally, we previously introduced a framework for generating palm photos using a "Style-based generator" named "StyleGAN2-ADA," which is a variation within the StyleGAN family.” [
18]– [
20]. This research was motivated by the recent success of the GAN family in current literature to generate very high-quality images [
16]– [
19]. Our current objective is to develop the model from the StyleGAN family, StyleGAN3, to demonstrate a more natural transformation process, where the pixel position of each detail is exclusively derived from the base features. To the best of our knowledge, ours is the only StyleGAN-based approach that can generate high-resolution palm images up to 2048x2048 pixels. In a previous study, a TV-GAN based framework was applied to generate palmprints. However, high resolution images were not generated in this work [
21]. Our contributions are as follows:
Figure 1.
Palmprint features definitions with principal lines and wrinkles.
• We explained the quality metric distributions to assess the diversity of the synthetic fingerprints and their similarity to original palm photos. We also match every synthetic palm photo to every original palm image to ensure that the synthetic palm images do not reveal the real identity.
•We made the pre-trained model and generated model publicly available. To the best of our knowledge, our study is the first publicly available StyleGAN-based palm photo synthesis model.
•To filter out unwanted images during the generation of synthetic images we applied the image processing method. To detect, describe the key-points of the images and also to match between original images to test images, we applied the Scale-Invariant Feature Transform (SIFT) algorithm.
The rest of the paper is organized as follows. Section II data discusses the pre-processing method and proposed model architecture. The data preparation for the experiment and model for training method is noted in Section III. Experimental results and evaluation are presented in Section iv. Finally, our conclusion is in Section v.