Learned Scanpaths Enhance Blind Panoramic Video Quality Assessment

Core Concepts

An end-to-end optimized blind panoramic video quality assessment method that explicitly models user viewing patterns through learned visual scanpaths.

Abstract

The content presents an end-to-end optimized blind panoramic video quality assessment (PVQA) method that consists of two modules: a scanpath generator and a quality assessor. The scanpath generator is initially trained to predict future scanpaths by minimizing their expected code length, and then jointly optimized with the quality assessor for quality prediction. The scanpath generator is probabilistic and can work with any planar video quality assessment (VQA) model, enabling direct quality assessment of panoramic images by treating them as videos composed of identical frames. The proposed method addresses the challenges posed by the spherical data structure of panoramic videos and the diverse and uncertain user viewing behaviors. Experiments on three public panoramic image and video quality datasets, encompassing both synthetic and authentic distortions, validate the superiority of the blind PVQA model over existing methods. The key highlights and insights are: The scanpath generator is differentiable and can be integrated with any planar VQA model, enabling end-to-end optimization. The scanpath generator is trained to predict future scanpaths by minimizing their expected code length, capturing the uncertainty and diversity of human viewing patterns. The proposed three-stage optimization strategy, involving pre-training, quality assessor warmup, and end-to-end finetuning, accelerates convergence. The learned scanpaths enhance the performance of all quality assessors compared to other scanpath-based methods, and the method outperforms existing blind PVQA models under both in-dataset and cross-dataset settings. The scanpath generator closely replicates human viewing patterns, as validated by metrics such as minimum orthodromic distance and maximum temporal correlation.

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The content does not provide any specific numerical data or statistics. The focus is on the methodology and evaluation of the proposed blind PVQA method.

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Key Insights Distilled From

Learned Scanpaths Aid Blind Panoramic Video Quality Assessment

by Kanglong Fan... at arxiv.org 04-02-2024

https://arxiv.org/pdf/2404.00252.pdf

Deeper Inquiries

How can the proposed blind PVQA method be extended to handle other types of immersive media, such as light field or holographic displays?

The proposed blind PVQA method can be extended to handle other types of immersive media by adapting the scanpath generation and quality assessment modules to suit the specific characteristics of light field or holographic displays. For light field displays, the scanpath generator can be modified to predict scanpaths that consider the additional depth information present in light field data. This may involve incorporating features related to parallax and depth perception into the scanpath prediction model. The quality assessment module can be adjusted to evaluate the quality of the rendered light field content, taking into account factors such as spatial resolution, angular resolution, and depth accuracy. Similarly, for holographic displays, the scanpath generator can be enhanced to predict scanpaths that optimize the viewing experience in a holographic environment. This may involve considering factors such as viewing angles, hologram brightness, and hologram stability in the prediction process. The quality assessment module can be tailored to assess the quality of holographic content, focusing on aspects like color accuracy, hologram sharpness, and visual comfort. By customizing the scanpath generation and quality assessment components to the specific requirements of light field or holographic displays, the blind PVQA method can be effectively extended to handle these types of immersive media, providing accurate and reliable quality assessment for a wider range of immersive viewing experiences.

What are the potential limitations of the scanpath-based approach, and how can they be addressed in future research?

One potential limitation of the scanpath-based approach is the reliance on predicted scanpaths, which may not always accurately represent human viewing behavior. Inaccurate scanpath predictions can lead to suboptimal quality assessments, especially in complex or dynamic scenes. To address this limitation, future research can focus on improving the accuracy of scanpath prediction models by incorporating more sophisticated algorithms, such as reinforcement learning or attention mechanisms, to better capture human gaze patterns. Another limitation is the computational complexity of generating scanpaths for large-scale immersive media datasets. The processing time and resource requirements for scanpath generation can be significant, especially when dealing with high-resolution or volumetric data. Future research can explore optimization techniques, parallel processing, or distributed computing to streamline the scanpath generation process and make it more efficient for large datasets. Additionally, the scanpath-based approach may struggle with generalizability across different types of immersive media or content genres. Scanpath models trained on specific datasets or content types may not perform well on unseen data. To enhance generalizability, future research can focus on developing transfer learning techniques or domain adaptation strategies to make scanpath models more robust and adaptable to diverse immersive media environments.

What insights can be gained from the learned scanpaths in terms of understanding human perception and attention in panoramic environments?

Learned scanpaths offer valuable insights into human perception and attention in panoramic environments by revealing how individuals visually explore and interact with immersive media content. By analyzing the patterns and trajectories of scanpaths, researchers can gain a deeper understanding of the following aspects: Visual Attention: Scanpaths can provide information on regions of interest and salient features within panoramic scenes, shedding light on what captures human attention in immersive environments. Perceptual Preferences: By studying scanpaths, researchers can identify common viewing patterns and preferences among viewers, helping to tailor content creation and presentation to align with audience expectations. Cognitive Processing: Scanpaths can offer insights into the cognitive processes involved in navigating and interpreting complex panoramic content, highlighting how viewers process visual information in immersive settings. User Engagement: Analysis of scanpaths can reveal how users engage with panoramic media, including factors that influence immersion, presence, and emotional responses to the content. Overall, learned scanpaths serve as a valuable tool for researchers to explore and understand human perception and attention in panoramic environments, offering a window into the intricate relationship between viewers and immersive media content.