Inspect Rich Documents with Gemini Multimodality and Multimodal RAG

📄 Inspect Rich Documents with Gemini Multimodality and Multimodal RAG
As enterprise data becomes increasingly complex, the need to analyze rich documents—such as PDFs, images, tables, scanned forms, and reports—has never been more urgent. Traditional text-based models fall short when faced with visual or structured content. That’s where Gemini’s multimodal capabilities and Multimodal RAG (Retrieval-Augmented Generation) come in.

In this article, you'll learn:

What Gemini multimodality offers

Why traditional RAG struggles with rich content

How Multimodal RAG solves this problem

Real-world use cases

How to implement a basic inspection pipeline using Gemini 1.5 Pro

🌐 Gemini Multimodality: More Than Just Text
Google's Gemini 1.5 Pro, available in Vertex AI, is a multimodal large language model (MLLM) that can accept combinations of:

🧾 Text

🖼️ Images

📄 PDFs

📊 Tables

📁 Code snippets

It can:

Read and interpret scanned documents

Understand visual layouts and complex tables

Cross-reference data across images and text

Analyze charts and structured forms

This makes it ideal for document intelligence tasks—especially when those documents go beyond plain text.

🔍 What Is Multimodal RAG?
Retrieval-Augmented Generation (RAG) improves LLM accuracy by retrieving relevant documents or content from a database before passing it to the model. Multimodal RAG takes this a step further by:

Indexing and retrieving images, PDFs, tables, or a mix of modalities

Letting the model reason over text and visuals together

Enabling context-aware QA from complex data

📘 Example: Given a 20-page financial report PDF with charts and footnotes, Multimodal RAG enables Gemini to:

Retrieve relevant sections and visuals

Understand the data points from charts

Answer “What is the net profit trend over the last 3 years?”

🧠 Real-World Use Cases
Industry Use Case
🏥 Healthcare Extract insights from medical forms and x-rays
💼 Legal Summarize and compare legal contracts
📊 Finance Analyze quarterly reports and charts
🏗️ Manufacturing Understand scanned checklists and invoices
🏛️ Government Process handwritten forms and old records

🛠️ How to Implement Gemini + Multimodal RAG
Here’s how you can build a simple Multimodal RAG pipeline using Gemini:

1. Preprocess & Chunk Documents Use pdfplumber, PyMuPDF, or Unstructured.io to extract text & images from PDFs

Store structured chunks in a vector DB like FAISS, Weaviate, or Pinecone

python
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from unstructured.partition.pdf import partition_pdf
chunks = partition_pdf("report.pdf") # returns text + image segments

1. Embed & Store in Vector DB
   Use multimodal embeddings or store image paths and chunk metadata.

2. Retrieve Relevant Chunks
   When a query is entered, retrieve relevant document snippets (text or image-based).

python
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query = "What is the revenue growth from 2020 to 2023?"
results = vector_db.search(query, top_k=5)

1. Pass to Gemini 1.5 Pro with Context Gemini supports file input via Vertex AI SDK:

python
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from vertexai.generative_models import GenerativeModel

model = GenerativeModel("gemini-1.5-pro")

response = model.generate_content(
[
"Answer this question based on the uploaded document:",
f"Question: {query}"
],
files={"document": open("chunk1.pdf", "rb")}
)
print(response.text)
You can pass multiple files (images, CSVs, etc.) together.

💡 Best Practices for Rich Document QA
🧠 Add OCR for scanned files (e.g., Tesseract or Google Document AI)

🧩 Use chunk overlap to preserve context

🧾 Maintain layout by storing positional metadata (X-Y axis from PDFs)

📦 Compress large PDFs or resize images before sending to Gemini

🚀 Power Use Case: Board Meeting Intelligence Tool
Imagine uploading:

30-page PDF board meeting slides

A ZIP file of Excel budget sheets

Product screenshots (JPG)

A Word doc of notes

And asking:

“Summarize our revenue performance, budget allocation changes, and product roadmap updates.”

Multimodal RAG with Gemini can piece all of that together—text, images, and tables—and give you one cohesive answer.

🔚 Conclusion
Inspecting rich documents isn’t just about reading text. It’s about interpreting layout, visuals, structure, and relationships across modalities. With Gemini's multimodal capabilities and a Multimodal RAG approach, you can build intelligent document processing pipelines for almost any industry.

Start today with Gemini in Vertex AI Studio, or build your own app with the Python SDK.