Text Display

Class: TextDisplayVisualizationBlockV1

Source: inference.core.workflows.core_steps.visualizations.text_display.v1.TextDisplayVisualizationBlockV1

The Text Display block renders text on an image with full control over styling and positioning.

Dynamic Text Content

Text content can be parameterized with workflow execution outcomes using the same templating syntax as Email and SMS notification blocks:

text = "Detected {{ $parameters.count }} objects of class {{ $parameters.class_name }}"

Parameters are provided via the text_parameters field:

text_parameters = {
    "count": "$steps.model.predictions",
    "class_name": "$inputs.target_class"
}

You can apply transformations to parameters using text_parameters_operations:

text_parameters_operations = {
    "count": [{"type": "SequenceLength"}]
}

Styling Options

• text_color: Color of the text. Supports:
• Supervision color names (uppercase): "WHITE", "BLACK", "RED", "GREEN", "BLUE", "YELLOW", "ROBOFLOW", etc.
• Hex format: "#RRGGBB" (e.g., "#FF0000" for red)
• RGB format: "rgb(R, G, B)" (e.g., "rgb(255, 0, 0)" for red)
• BGR format: "bgr(B, G, R)" (e.g., "bgr(0, 0, 255)" for red)
• background_color: Background color behind the text. Supports the same color formats as text_color. Use "transparent" for no background.
• background_opacity: Transparency of the background (0.0 = fully transparent, 1.0 = fully opaque)
• font_scale: Scale factor for the font size
• font_thickness: Thickness of the text strokes
• padding: Padding around the text in pixels
• text_align: Horizontal text alignment ("left", "center", "right")
• border_radius: Radius for rounded corners on the background

Positioning Options

The block supports both absolute and relative positioning:

Absolute Positioning (position_mode = "absolute"): - position_x: X coordinate in pixels from the left edge - position_y: Y coordinate in pixels from the top edge

Relative Positioning (position_mode = "relative"): - anchor: Where to anchor the text ("center", "top_left", "top_center", "top_right", "bottom_left", "bottom_center", "bottom_right", "center_left", "center_right") - offset_x: Horizontal offset from the anchor point (positive = right) - offset_y: Vertical offset from the anchor point (positive = down)

Type identifier

Use the following identifier in step "type" field: roboflow_core/text_display@v1to add the block as as step in your workflow.

Properties

Name	Type	Description	Refs
name	str	Enter a unique identifier for this step..	❌
text	str	The text content to display. Supports parameter interpolation using {{ $parameters.name }} syntax..	❌
text_parameters	Dict[str, Union[bool, float, int, str]]	Parameters to interpolate into the text..	✅
text_parameters_operations	Dict[str, List[Union[ClassificationPropertyExtract, ConvertDictionaryToJSON, ConvertImageToBase64, ConvertImageToJPEG, DetectionsFilter, DetectionsOffset, DetectionsPropertyExtract, DetectionsRename, DetectionsSelection, DetectionsShift, DetectionsToDictionary, Divide, ExtractDetectionProperty, ExtractFrameMetadata, ExtractImageProperty, LookupTable, Multiply, NumberRound, NumericSequenceAggregate, PickDetectionsByParentClass, RandomNumber, SequenceAggregate, SequenceApply, SequenceElementsCount, SequenceLength, SequenceMap, SortDetections, StringMatches, StringSubSequence, StringToLowerCase, StringToUpperCase, TimestampToISOFormat, ToBoolean, ToNumber, ToString]]]	Operations to apply to text parameters before interpolation..	❌
text_color	str	Color of the text. Supports supervision color names (WHITE, BLACK, RED, GREEN, BLUE, YELLOW, ROBOFLOW, etc.), hex format (#RRGGBB), rgb(R,G,B) format, or bgr(B,G,R) format..	✅
background_color	str	Background color behind the text. Supports the same color formats as text_color. Use 'transparent' for no background..	✅
background_opacity	float	Opacity of the background (0.0 = fully transparent, 1.0 = fully opaque)..	✅
font_scale	float	Scale factor for the font size..	✅
font_thickness	int	Thickness of the text strokes..	✅
padding	int	Padding around the text in pixels..	✅
text_align	str	Horizontal alignment of the text within its bounding box..	✅
border_radius	int	Radius for rounded corners on the background rectangle..	✅
position_mode	str	Positioning mode: 'absolute' uses exact pixel coordinates, 'relative' uses anchor points with offsets..	✅
position_x	int	X coordinate (pixels from left edge) when using absolute positioning..	✅
position_y	int	Y coordinate (pixels from top edge) when using absolute positioning..	✅
anchor	str	Anchor point for relative positioning..	✅
offset_x	int	Horizontal offset from anchor point (positive = right)..	✅
offset_y	int	Vertical offset from anchor point (positive = down)..	✅
copy_image	bool	Whether to copy the input image before drawing (preserves original)..	✅

The Refs column marks possibility to parametrise the property with dynamic values available in workflow runtime. See Bindings for more info.

Available Connections

Compatible Blocks

Check what blocks you can connect to Text Display in version v1.

• inputs: Motion Detection, PTZ Tracking (ONVIF).md), Image Preprocessing, Webhook Sink, Qwen2.5-VL, Detections Classes Replacement, Path Deviation, Stitch OCR Detections, Google Gemini, Triangle Visualization, Slack Notification, Detections Stitch, Barcode Detection, Bounding Box Visualization, Stitch Images, Email Notification, LMM For Classification, Morphological Transformation, Icon Visualization, Anthropic Claude, Mask Area Measurement, Grid Visualization, Heatmap Visualization, Property Definition, Detections Filter, Bounding Rectangle, Model Comparison Visualization, OpenAI, Distance Measurement, Cache Get, Path Deviation, Email Notification, Twilio SMS Notification, Perception Encoder Embedding Model, Absolute Static Crop, Byte Tracker, Detections List Roll-Up, Delta Filter, Halo Visualization, Local File Sink, Detections Merge, Stability AI Outpainting, Florence-2 Model, OpenAI, Clip Comparison, Detection Event Log, Dynamic Zone, VLM As Classifier, SAM 3, Time in Zone, Seg Preview, Keypoint Visualization, SmolVLM2, Roboflow Custom Metadata, Background Color Visualization, Camera Focus, Template Matching, Instance Segmentation Model, Line Counter, CLIP Embedding Model, Detections Consensus, Velocity, Polygon Visualization, VLM As Detector, Anthropic Claude, Time in Zone, Camera Focus, Keypoint Detection Model, Mask Visualization, Line Counter, Llama 3.2 Vision, Detection Offset, Classification Label Visualization, Byte Tracker, OpenAI, Line Counter Visualization, Single-Label Classification Model, Clip Comparison, Keypoint Detection Model, Identify Outliers, SIFT Comparison, Image Convert Grayscale, Polygon Zone Visualization, Detections Stabilizer, Relative Static Crop, Stitch OCR Detections, CSV Formatter, Byte Tracker, EasyOCR, Continue If, Data Aggregator, OCR Model, Detections Transformation, Dimension Collapse, Roboflow Dataset Upload, Contrast Equalization, Corner Visualization, Text Display, Time in Zone, Image Slicer, Dynamic Crop, SIFT Comparison, Detections Combine, SIFT, CogVLM, Identify Changes, Expression, Halo Visualization, Overlap Filter, Object Detection Model, Size Measurement, QR Code Generator, Google Vision OCR, Gaze Detection, Image Blur, Florence-2 Model, Instance Segmentation Model, QR Code Detection, Google Gemini, Blur Visualization, Environment Secrets Store, Cosine Similarity, JSON Parser, Google Gemini, Multi-Label Classification Model, Roboflow Dataset Upload, Single-Label Classification Model, Dot Visualization, Dominant Color, VLM As Classifier, Image Contours, SAM 3, Stability AI Image Generation, First Non Empty Or Default, Ellipse Visualization, Pixelate Visualization, Reference Path Visualization, Pixel Color Count, Multi-Label Classification Model, Moondream2, YOLO-World Model, Crop Visualization, Twilio SMS/MMS Notification, Circle Visualization, Trace Visualization, Rate Limiter, Color Visualization, Qwen3-VL, Object Detection Model, OpenAI, Segment Anything 2 Model, Polygon Visualization, Cache Set, Image Threshold, Model Monitoring Inference Aggregator, VLM As Detector, Stability AI Inpainting, Buffer, Background Subtraction, Image Slicer, Perspective Correction, Camera Calibration, Depth Estimation, Label Visualization, Anthropic Claude, LMM, SAM 3
• outputs: Motion Detection, Polygon Zone Visualization, Detections Stabilizer, Relative Static Crop, Image Preprocessing, Qwen2.5-VL, Byte Tracker, EasyOCR, OCR Model, Google Gemini, Roboflow Dataset Upload, Contrast Equalization, Corner Visualization, Triangle Visualization, Text Display, Image Slicer, Dynamic Crop, Detections Stitch, Barcode Detection, Stitch Images, Bounding Box Visualization, CogVLM, SIFT, Email Notification, LMM For Classification, Morphological Transformation, Icon Visualization, Anthropic Claude, Halo Visualization, Object Detection Model, Google Vision OCR, Heatmap Visualization, Gaze Detection, Florence-2 Model, Image Blur, Instance Segmentation Model, QR Code Detection, Google Gemini, Model Comparison Visualization, OpenAI, Perception Encoder Embedding Model, Blur Visualization, Absolute Static Crop, Google Gemini, Multi-Label Classification Model, Halo Visualization, Roboflow Dataset Upload, Single-Label Classification Model, Dominant Color, Dot Visualization, Florence-2 Model, OpenAI, Stability AI Outpainting, VLM As Classifier, Clip Comparison, Image Contours, SAM 3, VLM As Classifier, Stability AI Image Generation, Ellipse Visualization, Pixelate Visualization, SAM 3, Seg Preview, Reference Path Visualization, Pixel Color Count, Multi-Label Classification Model, Moondream2, Keypoint Visualization, YOLO-World Model, Crop Visualization, Twilio SMS/MMS Notification, Circle Visualization, SmolVLM2, Background Color Visualization, Trace Visualization, Template Matching, Instance Segmentation Model, Camera Focus, Color Visualization, CLIP Embedding Model, Qwen3-VL, Polygon Visualization, Object Detection Model, VLM As Detector, OpenAI, Segment Anything 2 Model, Anthropic Claude, Polygon Visualization, Image Threshold, Time in Zone, Camera Focus, Keypoint Detection Model, Mask Visualization, Llama 3.2 Vision, VLM As Detector, Stability AI Inpainting, Buffer, Classification Label Visualization, OpenAI, Background Subtraction, Image Slicer, Line Counter Visualization, Single-Label Classification Model, Perspective Correction, Clip Comparison, Keypoint Detection Model, Camera Calibration, Depth Estimation, Label Visualization, SIFT Comparison, Image Convert Grayscale, Anthropic Claude, LMM, SAM 3

Input and Output Bindings

The available connections depend on its binding kinds. Check what binding kinds Text Display in version v1 has.

Bindings

• input

  • image (image): The image to display text on..
  • text_parameters (*): Parameters to interpolate into the text..
  • text_color (string): Color of the text. Supports supervision color names (WHITE, BLACK, RED, GREEN, BLUE, YELLOW, ROBOFLOW, etc.), hex format (#RRGGBB), rgb(R,G,B) format, or bgr(B,G,R) format..
  • background_color (string): Background color behind the text. Supports the same color formats as text_color. Use 'transparent' for no background..
  • background_opacity (float_zero_to_one): Opacity of the background (0.0 = fully transparent, 1.0 = fully opaque)..
  • font_scale (float): Scale factor for the font size..
  • font_thickness (integer): Thickness of the text strokes..
  • padding (integer): Padding around the text in pixels..
  • text_align (string): Horizontal alignment of the text within its bounding box..
  • border_radius (integer): Radius for rounded corners on the background rectangle..
  • position_mode (string): Positioning mode: 'absolute' uses exact pixel coordinates, 'relative' uses anchor points with offsets..
  • position_x (integer): X coordinate (pixels from left edge) when using absolute positioning..
  • position_y (integer): Y coordinate (pixels from top edge) when using absolute positioning..
  • anchor (string): Anchor point for relative positioning..
  • offset_x (integer): Horizontal offset from anchor point (positive = right)..
  • offset_y (integer): Vertical offset from anchor point (positive = down)..
  • copy_image (boolean): Whether to copy the input image before drawing (preserves original)..

• output

  • image (image): Image in workflows.

Example JSON definition of step Text Display in version v1

{
    "name": "<your_step_name_here>",
    "type": "roboflow_core/text_display@v1",
    "image": "$inputs.image",
    "text": "Detection count: {{ $parameters.count }}",
    "text_parameters": {
        "class_name": "$inputs.target_class",
        "count": "$steps.model.predictions"
    },
    "text_parameters_operations": {
        "count": [
            {
                "type": "SequenceLength"
            }
        ]
    },
    "text_color": "WHITE",
    "background_color": "BLACK",
    "background_opacity": 1.0,
    "font_scale": 1.0,
    "font_thickness": 1,
    "padding": 5,
    "text_align": "left",
    "border_radius": 0,
    "position_mode": "absolute",
    "position_x": 10,
    "position_y": 10,
    "anchor": "center",
    "offset_x": 0,
    "offset_y": 0,
    "copy_image": true
}