Ranked Window Query Retrieval over Video Repositories
Bibliographic record
Abstract
Recent advances in Computer Vision have contributed to solid accuracy and efficiency improvements in many tasks such as object detection and tracking, enabling new opportunities for video analytics. In this paper, we initiate the study of ranked window queries that aim to retrieve clips from large video repositories in which objects co-occur in a query-specified fashion. For example, ranked window queries allow retrieval of clips of a set duration (e.g., 10 seconds) with the highest score from a long video, where at least the same 3 cars (with matching conditions based on suitably defined metadata) appear jointly. To answer such queries, we propose a two-phased approach, which builds indexes for all desired objects of the given videos during an Ingestion Phase and evaluates query answers efficiently in the Query Phase. During the Ingestion Phase, the proposed Partition-Based Index Construction (PBIC) algorithm builds indexes on partitions obtained by splitting each given video. Leveraging such indexes, queries are answered in the Query Phase using the Partition-Based Query Processing (PBQP) algorithm, which efficiently produces the desired (query-specified) number of results with the highest scores. We present the outcome of a thorough performance study on real videos that evaluates the performance of the proposed algorithms by varying parameters of interest. Our results indicate that the proposed set of techniques are capable of processing queries efficiently at scale, demonstrating multiple orders of magnitude speedups over other applicable approaches.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.009 |
| Meta-epidemiology (narrow) | 0.002 | 0.000 |
| Meta-epidemiology (broad) | 0.003 | 0.001 |
| Bibliometrics | 0.003 | 0.005 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.005 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".