Polygons (Bounding Boxes)

Overview

The polygons parameter, also commonly referred to as bounding boxes, is an option you can select in your Models. It indicates the precise polygonal area on the document where the value for each extracted field was detected.

• These polygons define the exact region on the document image containing the extracted data.

• They enable visual verification by highlighting where the model found each value on the document.

• This feature is especially useful for building user interfaces that overlay extracted data on document images for validation or review.

How It Works

• A polygon (bounding box) is an array of points outlining a closed shape around the detected data area.

• Points are given as normalized coordinates relative to the document page dimensions:

  • Each coordinate is a float between 0 and 1.

  • (0, 0) corresponds to the top-left corner; (1, 1) corresponds to the bottom-right corner.

• Multiple polygons can be returned if there are several extracted fields or data areas.

Example Polygon JSON Result

Here is an example of how the polygons parameter appears in the JSON response for a field named date:

"fields": {
  "date": {
    "locations": [
      {
        "polygon": [
          [0.15, 0.35],
          [0.85, 0.35],
          [0.85, 0.30],
          [0.15, 0.30]
        ],
        "page": 0
      }
    ],
    "confidence": null,
    "value": "2000-01-01"
  }
  ...
}

• The polygon array defines a rectangular bounding polygon for the detected date value on page 0.

• Coordinates are normalized floats from 0 to 1, relative to the page dimensions.

• locations can contain multiple polygon/page objects if the field appears multiple times or on multiple pages.

Use Cases

• Visual validation by overlaying bounding boxes on document previews for users to confirm extraction accuracy.

• Debugging extraction quality by analyzing detected regions.

• Enhancing UI with highlighted fields for better user experience.

How to activate Polygons?

Polygons option is only available to users with an active Pro or Business subscription.

When the Polygons feature is not activated, the locations keys in the JSON response will always be set to an empty list.