OpenSAL360: Open-Source Crowdsourcing Platform for Omnidirectional Video Saliency Collection
Authors: Alexey Bryncev, Andrey Moskalenko, Kira Shilovskaya, Ivan Kosmynin, Dmitriy Vatolin
Organizations: AI Center, Lomonosov Moscow State University MSU Institute for Artificial Intelligence Moscow, Russia · AI Center, Lomonosov Moscow State University MSU Institute for Artificial Intelligence, FusionBrain Lab Moscow, Russia · Lomonosov Moscow State University Moscow, Russia · MSU Institute for Artificial Intelligence Moscow, Russia
Omnidirectional video saliency prediction plays an important role in many immersive multimedia applications, including viewport-adaptive streaming and compression, foveated rendering, mesh simplification, perceptual quality assessment. Yet progress in this area remains constrained by the cost and complexity of collecting eye-tracking data with VR headsets, which makes large-scale dataset creation difficult to extend. We present OpenSAL360, the first open-source platform for scalable, low-cost 360° video saliency collection. Unlike conventional VR-based protocols, it requires only a standard screen, mouse, and internet connection, enabling parallel saliency data collection from common crowdsourcing assessors without specialized hardware. We validate our collection protocol against seven well-established VR eye-tracking datasets and conduct ablation studies on key interface, pre-, and post-processing parameters. To demonstrate the effectiveness and scalability of the proposed methodology, we collect and publicly release a saliency dataset covering 500 omnidirectional videos annotated by 2,000+ crowdsourcing assessors, making it, to the best of our knowledge, the largest dataset in this field. We make OpenSAL360 publicly available at https://github.com/msu-video-group/OpenSAL360.
Figures & tables
Figure 1. OpenSAL360 pipeline for scalable omnidirectional video saliency collection using crowdsourcing. OpenSAL360 pipeline for scalable omnidirectional video saliency collection using crowdsourcing.
Dataset (Year)
Video Sources
Tracking Sources
Unique Videos
Duration (s)
Participants All/Per Video
Resolution
Audio
PVS-HMEM (2018) ( Xu et al., 2018a )
YouTube/VRCun
HTC Vive/aGlass2
76
10–80
58 / 58
3K–8K
✗
Salient360! (2018) ( David et al., 2018 )
YouTube
HTC Vive/SMI
19
20
57 / 57
3840 × 1920
✗
VR-EyeTracking (2018) ( Xu et al., 2018b )
YouTube
HTC Vive/aGlass
208
20–60
45 / 31
4K
✓
VQA-ODV (2018) ( Li et al., 2018 )
YouTube
HTC Vive/aGlass
60
10–23
221 / 23
4K–8K
✓
SD360 (2018) ( Zhang et al., 2018 )
Sports-360
HTC Vive/aGlass
104
20–60
27 / 20
4K
✗
360_EM (2019) ( Agtzidis et al., 2019 )
YouTube
FOVE VR headset
15
38–60
13 / 13
1K–4K
✓
Table 1. Comparison of existing omnidirectional video saliency datasets. Our dataset, collected using the OpenSAL360 platform, provides substantially larger video and observer coverage through scalable crowdsourcing.
Figure 2. Average CC across seven validation datasets for selecting video trimming time (left), temporal offset (middle), and number of crowdsourced observers per video (right). Average CC across seven validation datasets for selecting video trimming time (left), temporal offset (middle), and number of crowdsourced observers per video (right).
Method
CC360
SIM360
NSS360
PAVER ( Yun et al., 2022 )
0.2238
0.2267
1.0675
ATSal ( Dahou et al., 2021 )
0.2337
0.2564
1.5945
SST-Sal ( Bernal-Berdun et al., 2022 )
0.3213
0.3157
2.0526
ViNet ( Jain et al., 2021 ) (ERP)
0.3848
0.3373
2.0240
SVGC-AVA ( Yang et al., 2023 )
0.4288
0.3717
2.2341
SalFoM ( Moradi et al., 2024 ) (ERP)
0.4309
0.3624
2.3717
Table 2. OpenSAL360 vs. automatic methods across all validation datasets. Best and second-best results are shown in bold and underlined ; bottom rows ablate viewing parameters (V), post-processing (P), and 100 observers before filtering (O).
This paper presents an overview of the NTIRE 2026 Challenge on Video Saliency Prediction. The goal of the challenge participants was to develop automatic saliency map prediction methods for the provided video sequences. The novel dataset of 2,000 diverse videos with an open license was prepared for this challenge. The fixations and corresponding saliency maps were collected using crowdsourced mouse tracking and contain viewing data from over 5,000 assessors. Evaluation was performed on a subset of 800 test videos using generally accepted quality metrics. The challenge attracted over 20 teams making submissions, and 7 teams passed the final phase with code review. All data used in this challenge is made publicly available - https://github.com/msu-video-group/NTIRE26_Saliency_Prediction.
Andrey Moskalenko, Alexey Bryncev, Ivan Kosmynin +40
Saliency estimation has received growing attention in recent years due to its importance in a wide range of applications. In the context of 360-degree video, it has been particularly valuable for tasks such as viewport prediction and immersive content optimization. In this paper, we propose SalFormer360, a novel saliency estimation model for 360-degree videos built on a transformer-based architecture. Our approach is based on the combination of an existing encoder architecture, SegFormer, and a custom decoder. The SegFormer model was originally developed for 2D segmentation tasks, and it has been fine-tuned to adapt it to 360-degree content. To further enhance prediction accuracy in our model, we incorporated Viewing Center Bias to reflect user attention in 360-degree environments. Extensive experiments on the three largest benchmark datasets for saliency estimation demonstrate that SalFormer360 outperforms existing state-of-the-art methods. In terms of Pearson Correlation Coefficient, our model achieves 8.4% higher performance on Sport360, 2.5% on PVS-HM, and 18.6% on VR-EyeTracking compared to previous state-of-the-art.
Mahmoud Z. A. Wahba, Francesco Barbato, Sara Baldoni +1
Department of Information Engineering, University of Padova, Via Gradenigo 6b, 35131, Padua, Italy
Video saliency prediction is inherently harder to model than static image saliency due to the additional temporal dimension. Video saliency benchmarks rest on the premise that predicting gaze on video requires utilizing temporal activity distributed across frames. Prior work has challenged this, showing that static baselines recover a significant fraction of the explainable gaze information on LEDOV, a popular video saliency dataset, and that video saliency models fail in the same places as this static baseline. We verify that this diagnosis still stands: under a more capable gold standard than the original analysis, and an updated panel of recent architectures, the strongest temporal architecture in the panel still does not substantially improve over a fine-tuned static baseline. However, it remains unclear whether the marginal gain reflects limitations of current temporal architectures or a lack of temporal patterns in the benchmark itself. We introduce SalTempto, a video saliency benchmark with greater dynamism: 224 clips of highly dynamic content, sourced from the HACS-Segments dataset so that each clip contains an event together with its lead-up and aftermath, with gaze recordings from up to 16 subjects and a training split for adapting pretrained models. On SalTempto, the static baseline recovers only about 13% of the headroom above the centerbias, against more than half on LEDOV. A fine-tuned temporal architecture shows a substantial gain in performance over the static baseline, indicating that it does capture meaningfully more temporal information, which LEDOV fails to measure. Yet, even this SoTA model still leaves nearly half of SalTempto's headroom unexplained, indicating room for improvement in video saliency modelling. Examination of SalTempto also lets us describe human tendencies that models miss. SalTempto link: https://huggingface.co/datasets/bethgelab/video_saliency.