Caption Generator

Generates textual descriptions of objects in a ROI, or of a ROI in the frame.


The Caption Generator node generates textual descriptions of objects within a Region of Interest (ROI), or of a ROI within the frame. This functionality is useful for applications requiring detailed descriptions of visual elements, enhancing accessibility, and providing contextual understanding.

Inputs & Outputs

  • Inputs: 1, Media Format: Raw Video
  • Outputs: 1, Media Format: Raw Video
  • Output Metadata: Captions


roi_labelsRegions of interest labelshiddenYes
roisRegions of interest. Type: polygon. Conditional on roi_labels.polygonnullYes
processing_modeProcessing mode. Options: ROIs, at an Interval (rois_interval), ROIs, upon a Trigger (rois_trigger), Objects in an ROI (objects).enumrois_intervalYes
triggerTrigger Condition. Queue ROI for lookup when this condition evaluates to true. Conditional on processing_mode being rois_trigger.trigger-conditionnull
objects_to_processObject types to process. ex. car,person, Conditional on processing_mode being objects.model-labelnull
min_obj_size_pixelsMin. width and height of an object. Conditional on processing_mode being objects.number64
obj_lookup_size_change_thresholdObject size ratio change threshold. Slider min: 0.1, max: 2.0, step: 0.2. Conditional on processing_mode being objects.slider0.1
max_lookups_per_objMax. attempts per object. Conditional on processing_mode being objects.number5
intervalLookup interval in seconds.number1
display_roiDisplay ROI on video?booltrue
display_objinfoDisplay results on video? Options: Disabled (disabled), Bottom left (bottom_left), Bottom right (bottom_right), Top left (top_left), Top right (top_right).enumbottom_left
debugLog debugging information?boolfalse


Output Metadata

Metadata PropertyDescription
nodes.node_id.recognized_objsList of recognized objects within the ROI.
nodes.node_id.recognized_obj_idsUnique identifiers for recognized objects.
nodes.node_id.recognized_obj_countThe number of recognized objects.
nodes.node_id.recognized_obj_deltaChanges in the count of recognized objects.
nodes.node_id.value_changed_deltaChanges in the values associated with recognized objects.
nodes.node_id.unrecognized_obj_countThe number of unrecognized objects.
nodes.node_id.unrecognized_obj_deltaChanges in the count of unrecognized objects.

Example JSON