Overview

The OCR node allows for performing OCR (Optical Character Recognition) on objects within a Region of Interest (ROI), or on a ROI within the frame. This functionality is crucial for applications requiring text recognition and extraction from video feeds.

Inputs & Outputs

Input media: Raw Video.
Output media: Raw Video.
Output metadata: nodes.node_id, +-- recognized_objs, +-- recognized_obj_ids, +-- recognized_obj_count, +-- recognized_obj_delta, +-- value_changed_delta, +-- unrecognized_obj_count, +-- unrecognized_obj_delta.

Properties

Property	Description	Type	Default	Required
`roi_labels`	Regions of interest labels	`string`	—	No
`rois`	Regions of interest. Conditional on `roi_labels`. Format: comma-separated normalized `x,y` coordinate pairs; separate multiple polygons with semicolons (for example, `0.1,0.1,0.9,0.1,0.9,0.9`).	`string`	`null`	No
`processing_mode`	Processing mode. Options: ROIs, at an Interval (`rois_interval`); ROIs, upon a Trigger (`rois_trigger`); Objects in an ROI (`objects`).	`enum`	`rois_interval`	Yes
`trigger`	Queue ROI for OCR when this condition evaluates to true. Conditional on `processing_mode` being `rois_trigger`.	trigger-condition	`null`	Yes
`objects_to_process`	ex. `car`,`person`,`car.red`. Conditional on `processing_mode` being `objects`.	model-labels	`null`	No
`tracking_mode`	Tracking mode. Options: Centroid (`centroid`); Top center (`top-center`); Bottom center (`bottom-center`); Left center (`left-center`); Right center (`right-center`). Conditional on `processing_mode` being `objects`.	`enum`	`centroid`	No
`min_obj_size_pixels`	Min. width and height of an object. Conditional on `processing_mode` being `objects`.	`number`	`64`	No
`obj_lookup_size_change_threshold`	Object size ratio change threshold. Conditional on `processing_mode` being `objects`. Range: minimum `0.1`, maximum `2.0`. Step: `0.2`.	`float`	`0.1`	No
`max_lookups_per_obj`	Max. OCR attempts per object. Conditional on `processing_mode` being `objects`.	`number`	`5`	No
`group_ocr_results`	If enabled, the match pattern is applied to the group of texts instead of individual words.	`bool`	`false`	No
`ocr_match_pattern`	Only retain OCR results that match this Regular Expression pattern. Leave blank to keep unfiltered results.	`string`	`null`	No
`min_confidence`	Ignores OCR results if they are below this threshold. Range: minimum `0`, maximum `1`. Step: `0.05`.	`float`	`0.7`	No
`additional_orientations`	Additional orientations to consider for OCR. This is useful for recognizing text that is rotated at 90, 180, or 270 degrees. Options: 90 degrees (`90`); 180 degrees (`180`); 270 degrees (`270`). Format: array of selected option values.	`string[]`	`null`	No
`ocr_interval`	OCR lookups interval. Unit: seconds.	`number`	`1`	No
`display_roi`	Display ROI on video?	`bool`	`true`	No
`display_objinfo`	Display OCR info on video? Options: Disabled (`disabled`); Bottom left (`bottom_left`); Bottom right (`bottom_right`); Top left (`top_left`); Top right (`top_right`).	`enum`	`bottom_left`	No
`debug`	Log debugging information?	`bool`	`false`	No

Output Metadata

The fields below are declared by this node's metadata schema; the JSON values are representative examples.

Path	Type	Description
`nodes.<node_id>.rois.<roi_label>.label_changed_delta`	`boolean`	When the OCR caption of an ROI changes
`nodes.<node_id>.rois.<roi_label>.label_available`	`boolean`	When an OCR caption becomes available
`nodes.<node_id>.rois.<roi_label>.label`	`string`	Current model-generated result for this ROI.
`nodes.<node_id>.recognized_obj_count`	`integer`	Number of objects successfully processed in the current frame.
`nodes.<node_id>.recognized_obj_delta`	`integer`	When one or more new objects have an OCR caption assigned
`nodes.<node_id>.label_changed_obj_delta`	`integer`	When the OCR caption of one or more objects changes
`nodes.<node_id>.unrecognized_obj_count`	`integer`	Number of objects that could not be processed in the current frame.
`nodes.<node_id>.unrecognized_obj_delta`	`integer`	When one or more objects fail to be assigned an OCR caption
`nodes.<node_id>.recognized_obj_ids`	`array`	Array of tracking IDs of objects successfully processed by the node.
`nodes.<node_id>.objects_of_interest_keys`	`array`	Array of metadata keys that contain object IDs relevant to downstream integrations.
`nodes.<node_id>.type`	`string`	Identifies the node type that produced this metadata.

JSON example

{
  "nodes": {
    "ocr1": {
      "label_changed_obj_delta": 0,
      "objects_of_interest_keys": ["recognized_obj_ids"],
      "recognized_obj_count": 0,
      "recognized_obj_delta": 0,
      "recognized_obj_ids": [],
      "rois": {
        "roi1": {
          "label": "example",
          "label_available": false,
          "label_changed_delta": false
        }
      },
      "type": "ocr",
      "unrecognized_obj_count": 0,
      "unrecognized_obj_delta": 0
    }
  }
}

Additional details

Object labels and attributes

Object labels/classes added: In ROI mode, the configured ROI label is added as an object with class 10500.
Object attribute labels/classes added: ROI objects receive ocr_roi (10500); recognized text uses class 10502; successful results add ocr_results (10501).