Text Display

Display customizable text on an image with styling and positioning options.

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@v1 to add the block as a 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.

Input and Output Bindings

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

Input and output 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

{
	    "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
	}