Background Finger vein biometrics has evolved into a reliable biometric modality because of its inherent resistance to spoofing and robustness to external attacks. In recent years, advances in deep learning-based person identification using finger vein trait have further enhanced its performance and effectiveness. However, convolutional neural networks (CNNs) need large volumes of labeled data to perform well, and finger vein datasets are typically small, making this shortage of training samples one of the major obstacles to building reliable, deployable systems. Method This paper addresses that gap by combining transfer learning with Conditional GAN-based data augmentation to build a more robust finger vein recognition framework. Rather than relying on conventional augmentation alone, synthetic, class-conditioned finger vein images are generated using two GAN variants, Conditional DCGAN and Conditional WGAN-GP, which incorporate class-conditional information to enable stable, controllable adversarial training and improve intra-class compactness and inter-class discrimination while enriching the training data. To evaluate the generalization capability of the proposed approach, extensive experiments are conducted on two widely used benchmark databases, THU-FVFDT2 and FV-USM, under various data-split schemes. For classification, four established CNN architectures such as VGG19, MobileNetV2, InceptionV3, and EfficientNetV2-M were fine-tuned and evaluated using standard classification metrics for all partitioning schemes. Results The experimental results were consistently strong across both datasets and confirming that the framework generalizes well with consistently high classification accuracy across both datasets. As observed, MobileNetV2 reached 99.74% identification accuracy on THU-FVFDT2 dataset, while EfficientNetV2-M achieved the best overall accuracy 99.85% on FV-USM dataset using the Conditional DCGAN augmentation technique. Conclusion These findings suggest that pairing transfer learning with GAN-based augmentation is a practical, effective way to overcome data scarcity in finger vein recognition, offering a promising direction for dependable biometric systems.
Corresponding author: Partha Pratim Sarangi Competing interests: No competing interests were disclosed.
Grant information: This study was maintained by Kalinga Institute of Industrial Technology (KIIT) Deemed to be University, Bhubaneswar (KIIT-DU/1173/26). The study design, data collection and analysis, publication choices, and manuscript preparation were all done independently of the sponsoring organization.
The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Copyright: © 2026 Dash J et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. How to cite: Dash J, Sarangi PP and Mishra BSP. A Comprehensive Analysis of GAN-Based Data Augmentation and Transfer Learning for Finger Vein Biometrics [version 1; peer review: awaiting peer review]. F1000Research 2026, 15:1367 (https://doi.org/10.12688/f1000research.186234.1) First published: 13 Aug 2026, 15:1367 (https://doi.org/10.12688/f1000research.186234.1) Latest published: 13 Aug 2026, 15:1367 (https://doi.org/10.12688/f1000research.186234.1)
Researchers are being motivated to investigate more biometric characteristics by the growing need for safe and user-friendly biometric systems.1 Both fingerprints and finger-vein patterns are unique due to the intricate structure of the human finger. While many biometric modalities are still susceptible to spoofing2 attacks, intrinsic features like finger-vein and palm-vein3 detection have drawn more attention due to their increased user convenience, improved efficiency, and higher security. Because these traits originate within the human body, it is challenging to forge them. In addition, finger-vein imaging devices are quicker to assemble and smaller than palm-vein systems, making finger-vein recognition technology more widely used. Even with recent advances, Deep learning-driven finger vein identification4 remains challenging due to the restricted size of the accessible datasets, which restricts effective CNN training. As a result, existing methods are prone to overfitting, sensitivity to finger positioning, and inconsistent performance across datasets, while conventional augmentation techniques offer only limited data diversity. Although Generative Adversarial Networks (GAN)5 provide a promising solution through realistic sample generation, most existing architectures are computationally intensive, highlighting the need for a lightweight GAN framework tailored for finger-vein image enhancement.6,7,8,9 Vein patterns emerge as black network-like structures in the collected image, because in blood arteries, haemoglobin absorbs near-infrared light.,10 as illustrated in Figure 1.
To improve training stability of GAN-based finger vein recognition systems, this work employs Conditional DCGAN and Conditional WGAN-GP) as alternatives to the existing CRCGAN framework.11 Although CRCGAN mitigates the dual-dataset limitation of CycleGAN by performing adversarial learning at the feature level, its stability and robustness remain limited when dealing with complex class distributions and noisy finger vein images.
By incorporating class-conditional information, the proposed C-DCGAN and C-WGAN-GP enable more stable and controllable adversarial training, resulting in improved intra-class compactness and inter-class discrimination. In particular, C-DCGAN enhances stability through deep convolutional feature learning, while C-WGAN-GP further improves convergence by adopting the Wasserstein distance with gradient penalty, effectively alleviating mode collapse and gradient instability. Consequently, the proposed conditional GAN frameworks generate higher-quality and more discriminative finger vein samples, leading to improved recognition performance and robustness compared to CRCGAN, and are therefore more suitable for practical applications. The following is a summary of this work's primary contributions:
• We propose an efficient framework that leverages Conditional DCGAN and Conditional WGAN-GP) to produce accurate and discriminative finger vein representations, thereby enhancing the stability of the training process.
• We evaluate proposed framework on two publicly available datasets. The datasets utilized, the topologies of the suggested C-DCGAN and C-WGAN-GP models, and the evaluation criteria used to examine the accuracy and dependability of the synthesized finger vein representations.
• We conduct a comparative study employing transfer learning with popular CNN architectures, including VGG19, MobileNetV2, InceptionV3, and EfficientNetV2-M which are properly tuned and trained using both conventional data augmentation and GAN-based augmentation (C-DCGAN and C-WGAN-GP), to evaluate the effectiveness of the enhanced datasets.
The rest of the section is described as follows: Section 2 is covered with the related work. Section 3 labels the background study and Section 4 deliver a comprehensive the experimental study. Finally, Section 5 concludes the paper.
In finger vein identification systems, the total recognition performance is largely dependent on how well features are extracted.12 Numerous feature extraction techniques have been proposed to increase accuracy and robustness,13 which can be roughly categorized into three different groups.
.
• Traditional hand-made approaches include maximum curvature (MC),14 Local binary patterns (LBP),16 based on Gabor filtering,15 and their variations. For instance, Yang et al.17 presented ASAVE algorithm that minimizes the impact of finger displacement by extracting vein networks using orientation map–guided curvature. Furthermore, Yang et al.18 introduced a weighted vein-coding and index-integration framework aimed at improving both recognition accuracy and computational efficiency. Local Binary Pattern (LBP) and its variants characterize local image structure by capturing relationships among neighboring pixels, which makes them relatively robust to variations such as finger displacement. For example, the Weighted Local Descriptor (WLD)19 operator, an extension of LBP, and the SVM-based approach20 estimate vein width and approximate finger cross-sections using elliptical models, thereby improving feature extraction and helping to compensate for pose-related distortions in low-quality images. Similar to this, Lv et al.26 presented a method for extracting finger vein features that combines the pyramid of histograms of oriented gradients (PHOG) with the binary pattern of phase congruency (BPPC) to enable multi-scale feature representation while lessening the effects of local disturbances like changes in illumination. The merged feature set is subjected to the kernel discriminative common vector (KDCV) approach21 in order to obtain more discriminative, non-linear representations with a KNN classifier for personal identification.
• In standard representation learning, PCA, LDA,22 and related methods are commonly used. For example, Qiu et al.23 designed a double sliding-window method to precisely identify the locations of the phalangeal joints on finger vein images., followed by feature extraction using two-dimensional PCA(2DPCA) to achieve reliable recognition performance. More recently, Yang et al.7 proposed a low-rank representation constrained by low reconstruction error (SRLRRR), which uses low-rank structures to suppress noise and extract discriminative information, improving recognition accuracy.
• Using multilayer architectures, deep neural networks can automatically learn abstract and high-level representations of finger vein pictures.24 For instance, Das et al.25 created a five-layer deep CNN and showed how well it performed on four publicly available datasets. Shaheed and associates. Moreover, improper selection of SVM parameters26 often leads to poor classification accuracy and unstable performance Convolutional neural networks (CNN)4 dominated computer vision research and were the most widely adopted architectures for finger vein recognition prior to the introduction of Vision Transformers (ViTs).2728 suggested a CNN with residual connections that is deeply separable, achieving significant improvements in recognition accuracy. Although these approaches have achieved remarkable performance, their reliance on highly complex deep neural architectures introduces significant computational and memory overhead, reducing their suitability for real-time and embedded applications.29
• Lightweight deep learning architectures have attracted increasing attention for finger vein recognition as a means of addressing the computational limitations associated with conventional deep networks.30 Shen et al.31 presented an effective matching framework optimized utilizing a triplet loss function to accommodate real-time biometric applications, achieving competitive recognition performance with lower computational complexity. Chai et al.32 looked into the factors that affect lightweight network design and found that semi-pre-trained lightweight models consistently outperform networks trained from scratch, while rectangular convolutional kernels offer better feature representation than traditional square kernels. Huang et al.33 developed a frequency–spatial coupling network that simultaneously utilizes spatial and frequency-domain information, improving authentication accuracy by building on the complementing qualities of several feature domains.
Despite these developments, training reliable deep learning models is still severely hampered by the scarcity of varied finger vein samples. Despite the widespread use of Generative Adversarial Networks (GANs) for data augmentation, traditional GANs are frequently impacted by mode collapse and unstable training dynamics, which lower the quality and variety of the generated samples.34 The current work uses Conditional Wasserstein GAN with Gradient Penalty (C-WGAN-GP) and Conditional Deep Convolutional GAN (C-DCGAN) to address these issues. These models create high-quality, identity-preserving synthetic finger vein images that enhance the training dataset and boost recognition robustness by utilizing class-conditioned generation and enhanced optimization techniques. To improve feature selection and parameter optimization, metaheuristic optimization techniques have been investigated concurrently. Nevertheless, the original Wild Horse Optimizer (WHO) has limited search capabilities in high-dimensional spaces due to its susceptibility to premature convergence and decreased population variety during later optimization stages. In order to improve global exploration and prevent local optima, the Improved Binary Sparse Wild Horse Optimizer (IBSWHO) integrates Cauchy mutation, Sobol sequence initialization, and adaptive search techniques.38
• By combining the concepts of affinity maturation and clonal selection, the Binary Multi Objective Clonal Algorithm (BMCA) effectively achieves multi-objective optimization while simulating the adaptive behaviour of the biological immune system. It concurrently maximizes entropy and minimizes Pearson correlation while encoding band subsets as binary strings.39 By defining hyperspectral band selection, QUBO problem and using quantum superposition and tunnelling to avoid local minima, Quantum Annealer (QA)-based metaheuristics offer a novel method.40 In a quantum-enhanced framework, simultaneous band selection and classification are made possible by integrated quantum classifiers such as QBoost.
This section presents a thorough method that uses conditional GAN-based synthetic data to enhance finger vein recognition. To ensure strong and dependable recognition, the total framework is divided into four sequential stages: training strategy formulation, classifier architecture optimization, generative model construction, and thorough performance evaluation.
Two sophisticated conditional GAN frameworks, Conditional WGAN-GP and Conditional DCGAN, were used to provide high-quality synthetic training data in order to make up for the small amount of real finger vein images available for each class. The architectural configuration of each model is discussed in detail in the following subsections.
The objective function in C-DCGAN is well crafted the limited availability of actual finger vein images per class was addressed using two state-of-the-art GAN architectures to produce superior training samples. Among them, Conditional Deep Convolutional GAN (C-DCGAN)35 extends the conventional DCGAN framework by conditioning both the generator and discriminator on class labels, thereby enabling the generation of class-aware finger vein images.
Generator architecture: A 100-dimensional latent noise vector concatenated with one-hot encoded class labels is sent into the generator. Its four transposed convolutional layers are followed by ReLU activation and batch normalization. It ends with a Tanh-activated output layer that produces 180 × 50-pixel grayscale images.
Discriminator architecture: Five convolutional layers with Leaky ReLU activation (α = 0.2) make up the discriminator. All layers—aside from the first and last layers—are subject to batch normalization. Real and synthetic images are distinguished using a sigmoid-activated output layer after class label embeddings are merged at the feature level.
In a conditional GAN architecture, the auxiliary information y, including multimodal attributes or class labels, conditions the generator G (z|y) and the discriminator D (x|y), which are integrated as an additional input to direct the data creation process. In the generator a joint hidden representation is created by combining the conditional variable y with the prior noise input pz(z). This hidden representation may be built with a great deal of flexibility because of the adversarial training architecture.The objective function in C-DCGAN is well crafted to imitate the two-player mini-max game:
minmaxV(D,G)=Ex∼pdata(x)[logD(x|y)]+Ez∼pz(z)[log(1−D(G(z|y)))]
G D
The generator transmits the input noise vector z ∼ pz(z) and conditional information y, while the discriminator evaluates the authenticity of the generated and real samples conditioned on y to synthetic samples. The Non-saturating Generator Loss and Discriminator Loss functions are given below.
LG=−Ez∼pz(z)[logD(G(z|y)|y)]
LD=−Ex∼pdata(x|y)[logD(x|y)]−Ez∼pz(z)[log(1−D(G(z|y)|y))]
By using Wasserstein loss in combination with regularization of the gradient penalty, C-WGAN-GP enhances training stability and sample variety.36 The generator architecture follows that of the C-DCGAN, with the Wasserstein objective in place of the binary cross-entropy loss. The architecture of Conditional WGAN-GP is explained in Figure 2, which also demonstrates how Generator G and Critic D are used to train and validate both the produced and real samples. The discriminator, or critic, adds a gradient penalty term with a regularization coefficient of λ = 10 and does away with sigmoid activation. The generator loss is
The definition of a Wasserstein loss is:
LW=E[D(xreal|y)]−E[D(G(z|y)|y)]+λ°E(‖∇xˆD(xˆ|y‖)−1)2]
where xˆ is evenly sampled between real and produced samples along straight lines.
Hyperparameter Selection: Optimal hyperparameters for both architectures were established through ablation studies. The latent space dimensionality was set to 100, providing a favorable balance between generation quality and training constancy. For C-DCGAN and Conditional WGAN-GP, respectively, learning rates of 0.0002 and 0.0001 were used to provide steady critic optimization and efficient generator learning. Adam optimizer was used for both models with β1 = 0.5 and β2 = 0.999.
Training Protocol: With a batch size of 64, each Conditional DCGAN and Conditional WGAN-GP were trained for 100 and 50 epochs, respectively. Observing (i) the convergence behavior of the discriminator and generator losses and (ii) a qualitative visual examination of the synthesized samples to verify.
anatomical plausibility was used to evaluate training stability. Table 1 lists the hyperparameter setup settings for the Conditional DCGAN and Conditional WGAN-GP implementation.
Through transfer learning, pre-trained deep learning models offer a significant advantage in finger vein biometric verification by transferring representations from large-scale generic image datasets to the target biometric domain. This method enables efficient feature learning even with a small number of samples per subject by improving the generalization of the model and reducing training time while working with limited biometric data. The VGG19, MobileNetV2, InceptionV3, and EfficientNet-V2-M architectures were used and assessed in the FV-USM and THU-FVFDT2 datasets. All training and assessment parameters for all classification models are described in Table 2.
The VGG19 architecture was modified to process 180 × 50 × 1 grayscale pictures of finger veins. Five consecutive convolutional blocks with maximum-pooling layers 2 × 2 come after each of the 3 × 3 kernels with ReLU activation. The convolutional feature extractor is followed by Each of the three completely connected layers having 4096, 4096, and output-class neurons. To reduce overfitting, fully linked layers were subjected to a dropout rate of 0.5, and batch normalization after convolutional layers improved the stability and convergence of the training.
MobileNetV2 adopts a lightweight design based on Separable convolutions according to depth and inverted residual blocks with linear bottlenecks. The network was fine-tuned to accept 180×50×1 grayscale input by modifying the initial convolutional layer. Batch normalization and ReLU6 activation were utilized throughout the network to enhance numerical stability. Before the final classification layer, to enhance generalization and reduce parameter complexity, a global average pooling layer was employed.
InceptionV3 uses parallel convolutional filters with different receptive fields inside Inception modules to extract multi-scale features. By altering the input layer, the architecture was modified for grayscale photographs of the finger veins with a resolution of 180 × 50 × 1. In order to reduce computational cost and preserve effective gradient propagation during training, the design kept factorized convolutional layers. Before being transmitted to the last fully connected layer, whose output neurons match the predetermined target classes, the resultant feature representations were compressed using global average pooling.
In order to improve image quality and guarantee data consistency, the suggested system starts with a thorough preprocessing pipeline applied to the raw finger vein images. This pipeline includes region of interest (ROI) extraction, Contrast Limited Adaptive Histogram Equalization (CLAHE), and image normalization. A GAN-based augmentation module made up of Conditional Deep Convolutional GAN (C-DCGAN) and Conditional Wasserstein GAN with Gradient Penalty (C-WGAN-GP) receives the pre-processed pictures. Within this module, the generator synthesizes high-fidelity, identity-preserving finger vein images, while the discriminator learns to identify synthetic samples from authentic ones, therefore boosting the variety and representativeness of the training dataset. A convolutional neural network (CNN) based on transfer learning is then trained using the expanded dataset to carry out the final finger vein classification. Algorithm 1 provides a thorough explanation of the suggested methodology, and Figure 3 depicts the general structure.
Require: Finger vein dataset D, number of GAN training epochs N, gradient penalty coefficient λ (for C-WGAN-GP), batch size m
Ensure: Binary authentication decision yˆ ∈ {Yes, No}
1: Load dataset D from storage
2: for each image xi ∈ D do
3: Extract the finger vein region of interest (ROI)
4: Enhance contrast via CLAHE
5: Normalize pixel intensities to [0, 1]
6: end for
7. Dp ← {x i′}|D|
8. Partition Dp into Dtrain and Dtest
9: Initialize generator Gθ and discriminator/critic Dϕ with weights θ, ϕ
10: for epoch t = 1 to N do
11: Sample real mini-batch {x(j), y(j)}m ∼ Dtrain
12: Sample noise vectors {z(j)}m, z ∼ N (0, I)
13: if C-DCGAN is selected then
14 Generate fake images: xˆ(j) ← Gθ(z(j), y(j))
15: Minimize LG, LD as shown in Eq. (2), and Eq. (3)
16: else if C-WGAN-GP is selected then
17: Generate fake images: xˆ(j) ← Gθ(z(j), y(j))
18: Sample interpolation coefficients ϵ(j) ∼ U[0, 1]
19: Minimize LG, LW as shown in Eq. (4), and Eq. (5)
20: end if
21: Update ϕ ← ϕ − ηD ∇ϕ LD
22: Update θ ← θ − ηG ∇θ LG
23: end for
24: Produce augmented dataset: Daug ← Dtrain ∪ Gθ(z, y)
25: Load pre-trained CNN backbone F (VGG19/MobileNetV2/EfficientNet/InceptionV3)
26: Remove the original classification head of F
27: Attach new fully connected layers suited to the finger vein identity classes
28: Train M on Daug; apply early stopping on validation loss
29: Evaluate M on Dtest; record all performance metrics
30: for each query image xquery do
31: Apply Stage 1 preprocessing to xquery
32: Obtain identity score: s ← M (xquery)
33: if s ≥ τ then
34: Output: Yes (identified)
35 else
36: Output: No (rejected)
37: end if
38: end for
39: return Identification decision yˆ
Two publicly accessible finger vein datasets, THU-FVFDT2 and FV-USM, which offer a variety of biometric samples for thorough performance evaluation, are used to test the suggested methodology. Reliable model training and objective evaluation are made possible by the THU-FVFDT2 dataset, which includes session-wise area of interest (ROI) photos that capture comprehensive finger vein and dorsal finger texture information from a sizable cohort of participants. In addition, the FV-USM dataset includes multi-session and multi-finger photos that were gathered from a wide range of people. These images include differences in finger geometry and vascular patterns that closely resemble biometric situations found in the real world. When taken as a whole, these datasets cover a wide range of acquisition conditions, image resolutions, and inter-subject variability, offering a strict standard for assessing the efficacy, robustness, and generalization capacity of the suggested finger vein recognition and GAN-based data augmentation.
The region of interest (ROI) photos in the THU-FVFDT2 database5 include information on dorsal finger texture and finger veins that were gathered from 610 different patients. Of these, the first 220 participants come from the previous THU-FVFDT1 dataset, while the remaining 390 subjects were recruited and scanned over the course of two capture sessions spaced roughly three to seven days apart. The dataset is ideal for assessing the robustness and generalization capacity of finger vein recognition algorithms since this multi-session acquisition procedure creates genuine temporal changes. One session is set aside for testing and the other for model training. Every ROI has a 200 × 100-pixel resolution adjusted. Most of the participants are volunteers from the Graduate School of Tsinghua University in Shenzhen, including students and staff.
The FV-USM 37 database was created using photos obtained from 123 participants, comprising 40 female and 83 male University of Sains Malaysia employees and students. The participants were between the ages of 20 and 52. Every person’s left index, left middle, right index, and right middle fingers were recorded. The finger and vein patterns are two important biometric features in the obtained images. During a single acquisition session, each finger was scanned six times., which took place over two weeks apart for each participant. In the first session, 2,952 photos (123 × 4 × 6) were collected. Consequently, 5,904 pictures from both sessions—or 492 finger lessons—are included in the collection. A depth resolution of 256 gray levels and a spatial resolution of 640 × 480 pixels were used to capture finger images.
A personal computer with 16 GB of system memory and an Intel i5-8300H CPU operating at 2.30 GHz, and an NVIDIA GTX 1050 graphics processing unit with 8 GB of dedicated GPU RAM were used for all trials. The PyTorch framework (version 2.7), the torchvision library (version 0.22), and several auxiliary Python libraries for data preprocessing, training, and assessment were used to create deep learning models and related algorithms. GPU acceleration was used to boost processing efficiency during model training and inference.
The widely utilized approach of Contrast Limited Adaptive Histogram Equalization38 was utilized to enhance local contrast. While preserving normalized general brightness to improve image quality. Figure 4. shows a sample of the original and enhanced images from the THU-FVFDT2 data set. Histogram equalization is applied inside each sector once the image is divided into tiny, non-overlapping tiles, the method improves local contrast while limiting contrast amplification using a preset clip limit. In this method, the grayscale photos are processed using CLAHE with an 8x8 tile size and a clip limit of 3.0. This preprocessing procedure increases the vein pattern’s visibility, reduces illumination fluctuations, and inhibits noise amplification, all of which increase the dependability of later Phases of feature extraction and classification.
For the THU-FVFDT2 and FV-USM datasets, at first, the training set was expanded with additional data. The augmentation process involved manually cropping the finger vein region, rotating the image within a ±10° range, converting it to grayscale, and resizing it to 50 × 180 pixels (width × height). In previous research, augmentation was performed using state-of-the-art techniques for image improvement and traditional geometric alterations.
In the suggested methodology, Figure 5 illustrates sample augmented images from the THU-FVFDT2 and FV-USM datasets generated using a Conditional WGAN-GP model. Furthermore, Figure 6 presents the generator and discriminator loss curves over 50 training epochs for the THU-FVFDT2 and FV-USM datasets, respectively, obtained using Conditional WGAN based augmentation methods.
(a) THU-FVFDT2 dataset (b) FV-USM dataset.
Following training, the finger vein detection model’s performance is carefully evaluated. VGG19, MobileNetV2, InceptionV3, and EfficientNet-V2-M are among the deep learning architectures whose effectiveness is evaluated using performance metrics including accuracy, precision, recall, and f1-score. With training, validation, and testing splits of 70:15:15 and 80:10:10, respectively, two separate experiments employing distinct dataset partitioning techniques are carried out utilizing the Conditional DCGAN and Conditional WGAN-GP models. All performance measures utilized in various transfer learning strategies are listed in Table 3.
(2 × Precision × Recall) / (Precision + Recall)
This compares various deep learning architectures for finger vein detection using datasets enriched with the conditional DCGAN. The performance of the VGG19, MobileNetV2, InceptionV3, and EfficientNetV2-M models39 is evaluated to determine how the extension of the C-DCGAN-based data affects the classification efficacy. The comparison findings demonstrate the resilience and adaptability of the suggested C-DCGAN-assisted framework to various topologies of convolutional neural networks.
Table 4 and 5 includes the performance of the various CNN models from FV-USM data set for the C-DCGAN model, and EfficientNetV2-M and MobileNetV2 perform better with dividing of 70–15-15 and 80–10-10,40 respectively. Figures 7 and 8 show the graphs of Loss over epoch, Accuracy over epoch, and Macro Average Graph of the EfficientNetV2-M deep learning model.
Tables 6 and 7 include the performance of various CNN models from THU-FVFDT2 data set for the C-DCGAN model, and EfficientNetV2-M and MobileNetV2 perform better with the dividing of 70–15-15 and 80–10-10, respectively. The loss over epoch, accuracy over epoch, and macro average graphs of the MobileNetV2 deep learning model are displayed in Figures 9 and 10.
Figure 11 describes performance metrics using the conditional DCGAN augmentation technique with four transfer learning techniques with a data split of 70–15-15 and 80–10-10, respectively.
This paper uses datasets enhanced with a Conditional WGAN-GP to compare several CNN architectures. The impact of gradually enhanced Conditional WGAN-GP data on classification performance is investigated by analyzing the performance of VGG19, MobileNetV2, InceptionV3, and EfficientNetV2-M. The experimental findings show that the suggested Conditional WGAN-GP–based frame-work is robust and has better generalization capabilities across various convolutional neural network designs.
Tables 8 and 9 present the performance of various deep learning models that were trained using the C-WGAN-GP framework on the FV-USM data set. VGG19 and EfficientNetV2, two of the topologies assessed, perform better under the data partitioning techniques 70–15-15 and 80–10-10, respectively. The VGG19 model’s training dynamics are depicted in Figures 12 and 13, together with the macro-average performance graph, accuracy against the epoch curve, and loss vs epoch curve.
Tables 10 and 11 present the performance results of different deep learning models assessed using the THU- FVFDT2 dataset using the Conditional WGAN-GP frame-work. Among these, EfficientNetV2-M achieved superior performance with a data split of 70–15-15 and 80–10-10, respectively.
Figure 14 presents the comparative performance in terms of precision, precision, and recall using the C-WGAN-GP conditional enhancement framework. The evaluation is conducted with four transfer learning models—VGG19, MobileNetV2, InceptionV3, and EfficientNetV2-M—under data split configurations of 70–15–15 and 80–10–10, respectively.
The proposed approach uses Conditional DCGAN(C-DCGAN) and Conditional WGAN-GP(C-WGAN-GP) for both datasets, and C-DCGAN performs better than C-WGAN-GP. EfficientNetV2-M and MobileNetV2 were used as classifiers to evaluate the impact of augmented data. The results demonstrate consistently strong performance across both datasets, with maximum test accuracy of 0.9985 achieved for FV-USM database using EfficientNetV2-M with the 70–15–15% split. In general, these findings confirm that the integration of C-DCGAN-based augmentation with an appropriate data partitioning strategy effectively enhances finger vein recognition accuracy while maintaining robust generalization capability.
The variation in precision between training epochs for several C-DCGAN-based fin-ger vein identification models assessed on the THU-FVFDT2 and FV-USM datasets is shown in Figure 15. Effective feature learning made possible by GAN-driven data augmentation is demonstrated by all techniques’ quick accuracy gains in the early epochs, which are followed by stable convergence. In the FV-USM data set, EfficientNetV2-M performs best with a 70–15 to 15 splits, with an accuracy of 0.9985. Additionally, MobileNetV2 shows a competitive accuracy of more than 0.997 with reduced computational cost. The training stability and regularization advantages of the conditional DCGAN architecture are confirmed by smooth convergence trends.
A comparison of the suggested C-DCGAN and current finger vein detection techniques in several reference datasets is shown in Table 12. In both the THU-FVFDT2 and FV-USM datasets, the suggested method achieves the highest recognition accuracy, demonstrating its superior performance over previous techniques.
In this paper, we propose an efficient finger vein biometric framework for person identification under limited data conditions. The proposed approach integrates Conditional Deep Convolutional Generative Adversarial Networks (C-DCGAN) and Conditional Wasserstein Generative Adversarial Networks with Gradient Penalty (C-WGAN-GP) to enhance data diversity and representation learning. The main goal of the pro-posed method is to learn highly discriminative and robust feature representations from finger vein images while maintaining the integrity of inherent vein structures and to confirm the robustness and effectiveness of the proposed framework in both the THU-FVFDT2 and FV-USM datasets under varying data partition schemes. High classification accuracies are consistently observed regardless of the dataset or split ratio, reflecting strong generalization performance. In the THU-FVFDT2 dataset, MobileNetV2 with a 80–10–10 split achieves the highest accuracy of 0.9974, while EfficientNetV2-M demonstrates comparable performance in the 70–15–15 configuration. Similarly, for the FV-USM data set, EfficientNetV2-M achieves the best accuracy of 0.9985 with a split of 70–15-15, and MobileNetV2 produces a closely comparable accuracy of 0.9981 using the split of 80–10-10. Overall, the experimental evaluation demonstrates that the suggested architecture achieves accurate and reliable finger vein biometric identification. Additionally, the findings show that lightweight architectures, like MobileNetV2, provide the best possible balance between model complexity, computational efficiency, and recognition accuracy, making them ideal for real-time and resource-constrained biometric applications.
In order to verify the resilience and generalization of the suggested framework under various acquisition situations, future research will examine its applicability in cross-dataset and cross-sensor scenarios. Furthermore, a viable path for reducing annotation needs while enhancing the scalability, adaptability, and practicality of the suggested finger vein detection framework is to incorporate self-supervised and semi-supervised learning approaches. Global feature representation and identification efficiency could be further improved by combining transformer-based designs with attention methods.
There was no need for agreement or moral approval.
The datasets analysed in this study are not owned by the authors and therefore cannot be redistributed through this publication. The FV-USM and THU-FVFDT2 finger vein datasets are subject to the respective data providers' terms of use and distribution policies.
Researchers wishing to obtain these datasets should contact the original dataset providers and comply with their access requirements. The datasets are available only for research purposes and may require completion of a data access agreement or institutional approval before access is granted.
No additional ethical restrictions were imposed by the authors' institution because this study used previously collected and anonymized public research datasets. The Institutional Review Board (IRB) of the authors' institution did not require additional approval for data sharing, as no human participants were directly recruited by the authors and no identifiable personal information was collected.
The THU-FVFDT2 dataset is available at Graduate School at Shenzhen, Tsinghua University, upon reasonable request by submitting a signed license agreement to [email protected]. After the request is approved, the dataset can be downloaded, and the password required to extract the archived files will be provided by the dataset administrator.
The FV-USM dataset is available at University of Sains Malaysia upon request. Researchers may download the dataset from the official repository and obtain the password for accessing the archived files by contacting [email protected].
For accessing to data, the reviewers or readers may contact to corresponding author with the email address: [email protected]
The authors sincerely thank the Kalinga Institute of Industrial Technology, Bhubaneswar, for providing the necessary support and infrastructure that facilitated the publication of this article.
This study was maintained by Kalinga Institute of Industrial Technology (KIIT) Deemed to be University, Bhubaneswar (KIIT-DU/1173/26). The study design, data collection and analysis, publication choices, and manuscript preparation were all done independently of the sponsoring organization.
The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
© 2026 Dash J et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current Reviewer Status:
AWAITING PEER REVIEW
AWAITING PEER REVIEW
?
Key to Reviewer Statuses VIEW HIDE
ApprovedThe paper is scientifically sound in its current form and only minor, if any, improvements are suggested
Approved with reservations A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit.
Not approvedFundamental flaws in the paper seriously undermine the findings and conclusions