Comparison of Document Processing: Standard vs ColPali

Comparison of Standard Retrieval vs ColPali for Document Processing and Query

Overview

The image compares two methods for document retrieval and query: Standard Retrieval and ColPali (the latter being the improved method developed by authors). The comparison highlights processing times, the steps involved in each method, and the resulting performance metrics.

Standard Retrieval

• Processing Steps:
  1. OCR (Optical Character Recognition): Converts document images into text.
     • Offline Processing Time: 7.22 seconds per page
  2. Layout Detection: Identifies textual structure within the document.
  3. Captioning & Chunking: Breaks down the text into manageable segments.
  4. Text Embedding Model: Transforms text into a format suitable for similarity scoring.
• Query Processing:
  • Online Query Time: 22 milliseconds per query
  • Text Embedding Model: Utilized for generating the query response.
  • MaxSim Calculation: Computes similarity scores.
• Performance Metric:
  • NDCG@5 (Normalized Discounted Cumulative Gain): 0.66

Observations:

• Efficiency: Standard retrieval is relatively slow with an offline processing time of 7.22s per page.
• Accuracy: With an NDCG@5 score of 0.66, it shows a decent performance but leaves room for improvement in precision.

ColPali (Ours)

• Processing Steps:
  1. Vision LLM (Large Language Model):
     • Integrates vision encoder and LLM components.
     • Offline Processing Time: 0.39 seconds per page
  2. Vision Encoder: Encodes visual features from the document.
  3. LLM Integration: Processes visual features to comprehend content better.
• Query Processing:
  • Online Query Time: 30 milliseconds per query
  • LLM for Query Response: Uses encoded visual content for generating the query response.
  • MaxSim Calculation: Combines visual and textual similarity scores.
• Performance Metric:
  • NDCG@5 (Normalized Discounted Cumulative Gain): 0.81

Observations:

• Efficiency: ColPali improves the offline processing time significantly to 0.39s per page.
• Accuracy: Shows a higher NDCG@5 score of 0.81, indicating better retrieval accuracy and relevance.
• Trade-off: Slightly higher online query time (30ms) compared to Standard Retrieval (22ms), which is a small increase given the significant improvements in processing speed and accuracy.

Summary:

• Standard Retrieval:

  • Slower offline processing (7.22s/page)
  • Achieves NDCG@5 score of 0.66
  • Online query time: 22ms/query

• ColPali:

  • Faster offline processing (0.39s/page)
  • Higher NDCG@5 score of 0.81
  • Slightly higher online query time: 30ms/query

Conclusion:

ColPali presents significant improvements in both processing speed and accuracy over the Standard Retrieval method, making it more suitable for efficient and precise document querying and retrieval tasks.