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New CG-Bench Sets Standard for Video Understanding

CG-Bench helps machines analyze long videos better with clue-based questions.

Guo Chen, Yicheng Liu, Yifei Huang, Yuping He, Baoqi Pei, Jilan Xu, Yali Wang, Tong Lu, Limin Wang

― 6 min read


CG-Bench: A New Benchmark CG-Bench: A New Benchmark for computers. CG-Bench redefines video understanding
Table of Contents

Video understanding is the task of analyzing video content to answer questions or extract meaningful information. With the rise of technology, people have developed ways to teach computers how to understand videos just like humans do. This is important for many applications, such as security, entertainment, education, and advertising.

Long Videos are particularly challenging for computers to analyze because they contain more information than short clips. Imagine trying to remember everything that happened in a movie compared to a quick YouTube video. It's a tough job! While many efforts have been made to assess how well computers can understand short videos, there's still a lot of work needed to improve how they handle longer videos.

The Need for Better Benchmarks

To evaluate how well computers can understand videos, researchers use something called benchmarks. Benchmarks are like testing standards - they help to measure how effectively the technology works. Recent benchmarks have focused mainly on short videos and often relied on multiple-choice questions. However, these methods can be limited as they don't necessarily require deep understanding. Sometimes, computers can guess right just by eliminating wrong answers, similar to the way you might guess on a quiz between two choices when you’re not sure.

This raises questions about how trustworthy these computer models really are. Imagine you're taking a test, and you’re just guessing the answers without really knowing the material - that’s not good, right?

Introducing CG-Bench

To tackle this problem, a new benchmark called CG-Bench has been introduced. CG-Bench is designed not only to ask questions but also to require computers to find clues in longer videos to answer them correctly. This way, it encourages the computers to actually "watch" and understand the content instead of just guessing.

CG-Bench consists of over 1,200 carefully selected videos that are sorted into different categories, ensuring diversity in content. It includes questions that test perception, reasoning, and even some tricky questions that require a bit of imagination. In total, there are more than 12,000 question-answer pairs, providing a wealth of information for testing.

How CG-Bench Works

CG-Bench stands out because it uses two new evaluation methods that focus on understanding. The first method requires the computer to point to the exact moments in the video that provide the answers to questions. It’s akin to asking a friend to show you where the good parts of a movie are while they're watching it with you.

The second method allows the computer to figure out clues based on the entire video instead of just specific snippets. This is like searching for treasure by exploring the whole island rather than just one area.

With these two methods, CG-Bench examines whether computers are truly grasping the video content or simply skimming through it. After all, understanding a video is a bit like solving a mystery; you need the right clues to find the solution.

Challenges with Long Videos

Long videos can be tricky. They can last anywhere from 10 minutes to over an hour, filled with tons of details. It's much harder for computers to piece together information from such extensive content compared to a short clip. Sometimes, they tend to forget important details because they are too focused on the main storyline.

Imagine watching a movie and getting lost halfway through because you're busy checking your phone. Even humans can struggle with long videos, so it's no surprise that computers face similar problems.

The Importance of Clue-Grounded Questions

In order for computers to do well in understanding long videos, it's crucial for them to get good at finding clues. Clue-grounded questions require models to identify specific scenes or moments in videos that relate to the questions being asked. For instance, if a question is about a character's action at a certain time, the model must find that exact moment in the video to respond accurately.

This method is all about making sure the technology doesn’t just skim through information but engages deeply with the content. It’s akin to being asked, “What happened in that movie at the climax?” and needing to point to that exact scene rather than just giving a vague answer.

Evaluation Results

The results from testing various models with CG-Bench have shown that many of them struggle with understanding long videos. While some models perform well with short clips, they trip over their own feet when it comes to lengthier content. It’s like asking a sprinter to run a marathon – the skills don’t always transfer.

For instance, when tested on long videos, the scores achieved by some top models fell dramatically. This indicates a significant gap in the ability of current technology to process and analyze longer content effectively.

Interestingly, some models that performed excellently in the multiple-choice questions faced a significant drop in accuracy when subjected to deeper Evaluations based on credibility. It’s similar to when a student excels in multiple-choice tests but fails in open-ended questions that require critical thinking.

The Challenge of Human Evaluation

Another aspect of CG-Bench is the introduction of human evaluations to further analyze how well the models perform. This is crucial because even the best computer models can exhibit flaws in judgment. In light of this, human evaluators provide context and an additional layer of analysis through open-ended questions.

Having humans in the mix allows for a more rounded assessment. After all, if two people can watch the same video and walk away with two different opinions, wouldn’t it be beneficial to have human insight when evaluating machines?

Future Prospects

Looking ahead, CG-Bench aims to be a valuable resource in the ongoing quest to improve the capabilities of models in video understanding. The hope is that by pushing the boundaries of current technology, researchers can create models that genuinely understand the nuances of long videos rather than just being able to regurgitate information.

As technology continues to evolve, the dream is for models to become increasingly sophisticated in their ability to analyze video content, taking into account visual elements, audio cues, and even human emotions. The ultimate goal is for machines to not only answer questions accurately but to appreciate the content in a way that’s closer to how a human would.

Conclusion

In summary, CG-Bench is a significant development in the field of video understanding. By shifting the focus from simply answering questions to deeper understanding through clues, it paves the way for more reliable and capable models. It reminds us that like a good detective story, the journey toward understanding is often filled with twists, turns, and plenty of clues to find!

With continued efforts, we can hope for improvements that will allow technology to not only watch videos but to truly comprehend and engage with them. After all, whether it's film, home videos, or just watching cat antics online, there's always something to learn from a good watch!

Original Source

Title: CG-Bench: Clue-grounded Question Answering Benchmark for Long Video Understanding

Abstract: Most existing video understanding benchmarks for multimodal large language models (MLLMs) focus only on short videos. The limited number of benchmarks for long video understanding often rely solely on multiple-choice questions (MCQs). However, because of the inherent limitation of MCQ-based evaluation and the increasing reasoning ability of MLLMs, models can give the current answer purely by combining short video understanding with elimination, without genuinely understanding the video content. To address this gap, we introduce CG-Bench, a novel benchmark designed for clue-grounded question answering in long videos. CG-Bench emphasizes the model's ability to retrieve relevant clues for questions, enhancing evaluation credibility. It features 1,219 manually curated videos categorized by a granular system with 14 primary categories, 171 secondary categories, and 638 tertiary categories, making it the largest benchmark for long video analysis. The benchmark includes 12,129 QA pairs in three major question types: perception, reasoning, and hallucination. Compensating the drawbacks of pure MCQ-based evaluation, we design two novel clue-based evaluation methods: clue-grounded white box and black box evaluations, to assess whether the model generates answers based on the correct understanding of the video. We evaluate multiple closed-source and open-source MLLMs on CG-Bench. Results indicate that current models significantly underperform in understanding long videos compared to short ones, and a significant gap exists between open-source and commercial models. We hope CG-Bench can advance the development of more trustworthy and capable MLLMs for long video understanding. All annotations and video data are released at https://cg-bench.github.io/leaderboard/.

Authors: Guo Chen, Yicheng Liu, Yifei Huang, Yuping He, Baoqi Pei, Jilan Xu, Yali Wang, Tong Lu, Limin Wang

Last Update: Dec 16, 2024

Language: English

Source URL: https://arxiv.org/abs/2412.12075

Source PDF: https://arxiv.org/pdf/2412.12075

Licence: https://creativecommons.org/licenses/by/4.0/

Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.

Thank you to arxiv for use of its open access interoperability.

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