Hana Ben Fredj

Dr. Hana Ben Fredj


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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18 January 2020 in The Visual Computer
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Journal Article
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HFHana Ben Fredj
Hana Ben Fredj
SBSafa Bouguezzi
Safa Bouguezzi
Chokri SouaniChokri Souani
Chokri Souani

16 September 2021 in Electronics
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Journal Article
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SBSafa Bouguezzi
Safa Bouguezzi
HFHana Ben Fredj
Hana Ben Fredj
Tarek BelabedTarek Belabed
Tarek Belabed
Carlos ValderramaCarlos Valderrama
Carlos Valderrama
Hassene FaiedhHassene Faiedh
Hassene Faiedh
Chokri SouaniChokri Souani
Chokri Souani
Convolutional Neural Networks (CNN) continue to dominate research in the area of hardware acceleration using Field Programmable Gate Arrays (FPGA), proving its effectiveness in a variety of computer vision applications such as object segmentation, image classification, face detection, and traffic signs recognition, among others. However, there are numerous constraints for deploying CNNs on FPGA, including limited on-chip memory, CNN size, and configuration parameters. This paper introduces Ad-MobileNet, an advanced CNN model inspired by the baseline MobileNet model. The proposed model uses an Ad-depth engine, which is an improved version of the depth-wise separable convolution unit. Moreover, we propose an FPGA-based implementation model that supports the Mish, TanhExp, and ReLU activation functions. The experimental results using the CIFAR-10 dataset show that our Ad-MobileNet has a classification accuracy of 88.76% while requiring little computational hardware resources. Compared to state-of-the-art methods, our proposed method has a fairly high recognition rate while using fewer computational hardware resources. Indeed, the proposed model helps to reduce hardware resources by more than 41% compared to that of the baseline model.

4 September 2021 in Electronics
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Journal Article
Open access
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AAAnis AMMAR
Anis AMMAR
HFHana Ben Fredj
Hana Ben Fredj
Chokri SouaniChokri Souani
Chokri Souani
Motion estimation has become one of the most important techniques used in realtime computer vision application. There are several algorithms to estimate object motions. One of the most widespread techniques consists of calculating the apparent velocity field observed between two successive images of the same scene, known as the optical flow. However, the high accuracy of dense optical flow estimation is costly in run time. In this context, we designed an accurate motion estimation system based on the calculation of the optical flow of a moving object using the Lucas–Kanade algorithm. Our approach was applied on a local treatment region implemented into Raspberry Pi 4, with several improvements. The efficiency of our accurate realtime implementation was demonstrated by the experimental results, showing better performance than with the conventional calculation.

22 March 2021
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Conference Paper
Closed access
AAAnis AMMAR
Anis AMMAR
HFHana Ben Fredj
Hana Ben Fredj
Chokri SouaniChokri Souani
Chokri Souani
Motion estimation is considered among the most famous and important applications in the field of computer vision. Indeed, in the last decade, the optical flow has become an alternative technique to estimate motion on successive frames. However, dense and precise estimates of the optical flow are usually costly in computing time. In this context, our approach is focused upon calculating the moving object's optical flow through the use of the Lucas-Kanade algorithm in real time which is implemented into Raspberry Pi 4. The efficiency of our real time implementation is demonstrated by the experimental results, hence showing better performances in comparison with the conventional calculation.

24 March 2026 in Electronics
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Journal Article
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HFHana Ben Fredj
Hana Ben Fredj
HGHatem Garrab
Hatem Garrab
Chokri SouaniChokri Souani
Chokri Souani
Automated identification of lumbar vertebrae plays a key role in modern spine analysis, offering valuable assistance for diagnostic assessment and preoperative decision-making. Despite recent progress in deep learning-based detection methods, accurately localizing vertebral structures remains challenging due to anatomical variability and heterogeneous image quality. To address the difficulty of capturing subtle vertebral structures, we introduce a Multi-Scale Channel Attention Block (MSCABlock) integrated into the YOLO11 backbone. Unlike conventional attention-based or multi-scale convolutional designs, MSCABlock jointly exploits channel-wise feature interaction and multi-scale receptive fields to enhance both local detail sensitivity and contextual representation, while preserving computational efficiency. The proposed approach is designed to improve detection performance without significantly increasing model complexity. Our model is trained and validated using only the AP-view images from the Burapha University Lumbar-Spine Dataset (BUU-LSPINE), which provides well-annotated lumbar spine X-ray images from 400 unique patients. The proposed approach operates in a fully end-to-end manner, allowing vertebrae to be identified directly from input images without relying on handcrafted feature engineering or complex preprocessing pipelines. Experimental evaluations show that the proposed model achieves strong detection performance, with mAP@0.5 and mAP@0.5–0.95 reaching 0.982 and 0.79, respectively, alongside a precision of 0.93 and a recall of 0.975. Compared with the YOLO11 baseline, ablation and efficiency analyses demonstrate that MSCABlock consistently improves detection performance. It introduces only marginal increases in model parameters and computational cost, thereby preserving a lightweight architecture and maintaining efficient inference. These results show that the optimized YOLO11-based system generalizes well across lumbar levels. It maintains reliable detection under challenging conditions, providing robust automated localization to support large-scale clinical spine analysis.

10 December 2023
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Book Chapter
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HFHana Ben Fredj
Hana Ben Fredj
RGRim Ghozzi
Rim Ghozzi
CSChokri Souani
Chokri Souani