Cropper API Ruby

The Ruby OCR SDK supports the Cropper API.

Using the sample below, we are going to illustrate how to extract the data that we want using the OCR SDK.
Cropper sample


require 'mindee'

# Init a new client
mindee_client = 'my-api-key')

# Load a file from disk
input_source = mindee_client.source_from_path('/path/to/the/file.ext')

# Parse the file
result = mindee_client.parse(

# Print a full summary of the parsed data in RST format
puts result.document

Output (RST):

:Mindee ID: 149ce775-8302-4798-8649-7eda9fb84a1a
:Filename: default_sample.jpg

:Product: mindee/cropper v1.0
:Rotation applied: No


Page Predictions

Page 0
:Document Cropper: Polygon with 26 points.
                   Polygon with 25 points.

Field Types

Standard Fields

These fields are generic and used in several products.

Basic Field

Each prediction object contains a set of fields that inherit from the generic Field class.
A typical Field object will have the following attributes:

  • value (String, Float, Integer, Boolean): corresponds to the field value. Can be nil if no value was extracted.
  • confidence (Float, nil): the confidence score of the field prediction.
  • bounding_box (Mindee::Geometry::Quadrilateral, nil): contains exactly 4 relative vertices (points) coordinates of a right rectangle containing the field in the document.
  • polygon (Mindee::Geometry::Polygon, nil): contains the relative vertices coordinates (Point) of a polygon containing the field in the image.
  • page_id (Integer, nil): the ID of the page, is nil when at document-level.
  • reconstructed (Boolean): indicates whether an object was reconstructed (not extracted as the API gave it).

Aside from the previous attributes, all basic fields have access to a to_s method that can be used to print their value as a string.

Position Field

The position field PositionField does not implement all the basic Field attributes, only bounding_box, polygon and page_id. On top of these, it has access to:

  • rectangle (Mindee::Geometry::Quadrilateral): a Polygon with four points that may be oriented (even beyond canvas).
  • quadrangle (Mindee::Geometry::Quadrilateral): a free polygon made up of four points.

Page-Level Fields

Some fields are constrained to the page level, and so will not be retrievable to through the document.


The following fields are extracted for Cropper V1:

Document Cropper

πŸ“„cropping (Array<PositionField>): List of documents found in the image.

for page in result.document.inference.pages do
  for cropping_elem in page.prediction.cropping do
    puts cropping_elem.polygon.to_s
    puts cropping_elem.quadrangle.to_s
    puts cropping_elem.rectangle.to_s
    puts cropping_elem.boundingBox.to_s


Join our Slack