Extracting data from images using vision language models

Use VLM-enhanced ICR when you need higher extraction accuracy on complex documents.

Common use cases include:

• Financial documents with complex tables
• Invoices with varied layouts
• Medical records with specialized terminology
• Legal documents with strict structure requirements
• Multi-language document analysis

VLM-enhanced mode combines ICR layout analysis with language-model reasoning to improve classification and structure detection.

How Nutrient helps

Nutrient Java SDK handles VLM-enhanced configuration, model orchestration, and JSON output generation.

The SDK handles:

• Configuring hybrid processing modes combining local ICR with VLM enhancement
• Managing AI model loading and VLM capability coordination
• Implementing advanced semantic element classification with confidence scoring
• Complex document structure analysis and enhanced layout understanding algorithms

Complete implementation

This example extracts structured JSON using VisionEngine.VlmEnhancedIcr:

package io.nutrient.Sample;

Import the required classes from the SDK:

import io.nutrient.sdk.Document;
import io.nutrient.sdk.Vision;
import io.nutrient.sdk.enums.VisionEngine;
import io.nutrient.sdk.exceptions.NutrientException;

import java.io.FileWriter;
import java.io.IOException;

public class ExtractDataFromImage {

Create the main method and declare thrown exceptions:

    public static void main(String[] args) throws NutrientException, IOException {

Loading and processing the image

Open the image in try-with-resources so resources are cleaned up after processing:

        try (Document document = Document.open("input.png")) {

Configuring VLM-enhanced mode

Set the vision engine to VisionEngine.VlmEnhancedIcr.

This mode improves:

• Table boundary detection
• Semantic element classification
• Reading order in complex layouts
• Understanding across document variations

            // Configure VLM-enhanced ICR engine for improved accuracy
            document.getSettings().getVisionSettings().setEngine(VisionEngine.VlmEnhancedIcr);

Creating a vision instance

Create a vision instance bound to the document with Vision.set(document):

            Vision vision = Vision.set(document);

Extracting structured content

Call extractContent() to run the VLM-enhanced pipeline.

In this mode, the pipeline performs:

• Initial ICR layout detection
• VLM-based semantic refinement
• Confidence scoring
• JSON generation with structure and coordinates

            String contentJson = vision.extractContent();

Write the JSON result to a file for downstream processing.

Use this output for indexing, validation, storage, or custom analysis:

            try (FileWriter writer = new FileWriter("output.json")) {
                writer.write(contentJson);
            }
        }
    }
}

Understanding the output

extractContent() returns structured JSON with layout and semantic metadata.

VLM-enhanced output includes:

• Document elements — Paragraphs, headings, tables, figures, equations, detected barcodes, and form-related regions
• Barcode data — Decoded barcode values with symbology information for supported 1D and 2D barcode types
• Bounding boxes — Pixel coordinates with improved boundary accuracy
• Hierarchical relationships — Parent-child structure across sections and blocks
• Element classification — Semantic types with confidence scores
• Reading order — Sequence for complex layouts and multicolumn content
• Semantic metadata — Additional attributes used in downstream processing

Use this JSON for form extraction, contract analysis, invoice parsing, and other high-accuracy workflows. For a barcode-focused workflow that keeps decoded values connected to layout context, refer to the read barcodes with Vision guide.

Error handling

Vision API throws VisionException when extraction fails.

Common failure scenarios include:

• The image file can’t be read due to path or permission issues
• Image data is corrupted or unsupported
• Required models are missing or inaccessible
• Available memory is insufficient for VLM-enhanced processing
• VLM enhancement fails due to connectivity or service issues when applicable
• Image format, resolution, or dimensions are unsupported

In production code:

• Catch VisionException.
• Return a clear error message.
• Log failure details for debugging.
• Add fallback logic (for example, retry in ICR mode).

Conclusion

Use this workflow for VLM-enhanced extraction:

1. Open the image document using try-with-resources for automatic resource cleanup.
2. Configure the vision settings with getSettings().getVisionSettings().setEngine(VisionEngine.VlmEnhancedIcr) for enhanced accuracy.
3. VLM-enhanced mode combines local ICR AI models with vision language model capabilities for superior document analysis.
4. Create a vision instance with Vision.set() to bind content extraction operations to the document.
5. Call extractContent() to invoke the VLM-enhanced processing pipeline.
6. The pipeline performs initial ICR layout analysis, applies VLM enhancement for semantic understanding, calculates confidence scores, and generates JSON output.
7. VLM enhancement improves table cell boundary detection, element classification accuracy, and reading order determination for complex layouts.
8. The method returns a JSON-formatted string containing document structure with elements, barcode values when present, bounding boxes, hierarchical relationships, reading order, and confidence scores.
9. Write the JSON content to a file using try-with-resources with FileWriter for automatic resource management.
10. Handle VisionException errors for robust error recovery with fallback strategies like pure ICR mode.
11. The JSON output enables integration with intelligent form extraction, contract analysis, invoice processing, and legal document parsing.
12. VLM-enhanced mode is ideal for complex documents where extraction accuracy is the priority.

For related image extraction workflows, refer to the Java SDK guides.

Download this ready-to-use sample package to explore VLM-enhanced extraction.