Heatmap Visualization¶
Class: HeatmapVisualizationBlockV1
Source: inference.core.workflows.core_steps.visualizations.heatmap.v1.HeatmapVisualizationBlockV1
Draw heatmaps on an image based on provided detections. Heat accumulates over time and is drawn as a semi-transparent overlay of blurred circles.
How This Block Works¶
This block takes an image and detection predictions and draws a heatmap. The block:
- Takes an image and predictions as input.
- Accumulates heat based on the position of detections.
- Draws a semi-transparent overlay of blurred circles representing the heat.
Common Use Cases¶
- Density Analysis: Visualize the density of objects in a scene.
- Traffic Monitoring: Identify high-traffic areas.
- Retail Analytics: Analyze foot traffic in stores.
Type identifier¶
Use the following identifier in step "type" field: roboflow_core/heatmap_visualization@v1to add the block as
as step in your workflow.
Properties¶
| Name | Type | Description | Refs |
|---|---|---|---|
name |
str |
Enter a unique identifier for this step.. | ❌ |
copy_image |
bool |
Enable this option to create a copy of the input image for visualization, preserving the original. Use this when stacking multiple visualizations.. | ✅ |
position |
str |
The position of the heatmap relative to the detection.. | ✅ |
opacity |
float |
Opacity of the overlay mask, between 0 and 1.. | ✅ |
radius |
int |
Radius of the heat circle.. | ✅ |
kernel_size |
int |
Kernel size for blurring the heatmap.. | ✅ |
top_hue |
int |
Hue at the top of the heatmap. Defaults to 0 (red).. | ✅ |
low_hue |
int |
Hue at the bottom of the heatmap. Defaults to 125 (blue).. | ✅ |
ignore_stationary |
bool |
If True, only moving objects (based on tracker ID) will contribute to the heatmap.. | ✅ |
motion_threshold |
int |
Minimum movement in pixels required to consider an object as moving.. | ✅ |
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 Heatmap Visualization in version v1.
- inputs:
Local File Sink,Background Color Visualization,Overlap Filter,Roboflow Dataset Upload,Polygon Zone Visualization,Line Counter Visualization,Path Deviation,Image Preprocessing,SAM 3,Instance Segmentation Model,SIFT Comparison,Segment Anything 2 Model,Absolute Static Crop,Qwen3.5-VL,LMM,Camera Focus,Keypoint Detection Model,Clip Comparison,Stability AI Outpainting,Heatmap Visualization,EasyOCR,Anthropic Claude,Mask Visualization,Text Display,VLM As Detector,Detection Event Log,Image Slicer,Stitch Images,OC-SORT Tracker,Roboflow Custom Metadata,Email Notification,OpenAI,Blur Visualization,Velocity,Detections Combine,SAM 3,GLM-OCR,Time in Zone,Background Subtraction,QR Code Generator,Mask Area Measurement,Multi-Label Classification Model,Object Detection Model,Webhook Sink,SAM 3,Twilio SMS Notification,CogVLM,S3 Sink,Detection Offset,Line Counter,Bounding Rectangle,SIFT,VLM As Classifier,Byte Tracker,Polygon Visualization,Trace Visualization,Pixel Color Count,Camera Focus,Pixelate Visualization,Object Detection Model,LMM For Classification,Reference Path Visualization,Line Counter,Contrast Equalization,Classification Label Visualization,Dynamic Crop,Halo Visualization,Anthropic Claude,Perspective Correction,JSON Parser,Grid Visualization,Email Notification,Depth Estimation,VLM As Classifier,Image Slicer,Model Comparison Visualization,Instance Segmentation Model,Image Blur,Seg Preview,OpenAI,Path Deviation,Google Vision OCR,OCR Model,Bounding Box Visualization,Gaze Detection,Halo Visualization,Ellipse Visualization,Triangle Visualization,Keypoint Detection Model,Florence-2 Model,Llama 3.2 Vision,Detections Stitch,YOLO-World Model,SORT Tracker,Label Visualization,Time in Zone,Florence-2 Model,Image Contours,Time in Zone,PTZ Tracking (ONVIF),Icon Visualization,Stability AI Image Generation,Anthropic Claude,Image Convert Grayscale,Google Gemini,Distance Measurement,Google Gemini,Byte Tracker,Moondream2,Crop Visualization,Corner Visualization,OpenAI,Stitch OCR Detections,Stitch OCR Detections,Detections Stabilizer,CSV Formatter,Byte Tracker,Polygon Visualization,Detections Transformation,Model Monitoring Inference Aggregator,Single-Label Classification Model,Circle Visualization,Relative Static Crop,Slack Notification,Camera Calibration,OpenAI,Identify Changes,Detections Filter,Cosine Similarity,Stability AI Inpainting,Keypoint Visualization,Detections Merge,Twilio SMS/MMS Notification,Dot Visualization,Identify Outliers,Color Visualization,Dynamic Zone,Image Threshold,Detections Classes Replacement,Detections List Roll-Up,Template Matching,Morphological Transformation,SIFT Comparison,Detections Consensus,Google Gemini,VLM As Detector,ByteTrack Tracker,Roboflow Dataset Upload,Motion Detection - outputs:
Background Color Visualization,OCR Model,Bounding Box Visualization,Roboflow Dataset Upload,Gaze Detection,Polygon Zone Visualization,Line Counter Visualization,Ellipse Visualization,Image Preprocessing,Triangle Visualization,Keypoint Detection Model,SAM 3,Instance Segmentation Model,Florence-2 Model,SIFT Comparison,Qwen3.5-VL,Segment Anything 2 Model,Absolute Static Crop,Llama 3.2 Vision,Detections Stitch,LMM,Camera Focus,Keypoint Detection Model,Clip Comparison,YOLO-World Model,Stability AI Outpainting,Anthropic Claude,EasyOCR,Heatmap Visualization,Mask Visualization,Text Display,VLM As Detector,SORT Tracker,Image Slicer,Label Visualization,Stitch Images,Barcode Detection,OC-SORT Tracker,Florence-2 Model,Image Contours,Time in Zone,OpenAI,Blur Visualization,SmolVLM2,Icon Visualization,Multi-Label Classification Model,Stability AI Image Generation,SAM 3,GLM-OCR,Anthropic Claude,Image Convert Grayscale,Perception Encoder Embedding Model,Google Gemini,Background Subtraction,Google Gemini,Multi-Label Classification Model,Moondream2,Crop Visualization,Qwen2.5-VL,Object Detection Model,Corner Visualization,OpenAI,SAM 3,Semantic Segmentation Model,Dominant Color,CogVLM,Detections Stabilizer,Polygon Visualization,Qwen3-VL,SIFT,VLM As Classifier,Single-Label Classification Model,Circle Visualization,Byte Tracker,Polygon Visualization,Relative Static Crop,Trace Visualization,Pixel Color Count,Camera Focus,Pixelate Visualization,Camera Calibration,OpenAI,LMM For Classification,Object Detection Model,Reference Path Visualization,Stability AI Inpainting,Keypoint Visualization,Contrast Equalization,Twilio SMS/MMS Notification,Classification Label Visualization,Dot Visualization,CLIP Embedding Model,Color Visualization,Dynamic Crop,Halo Visualization,Buffer,Anthropic Claude,Image Threshold,Perspective Correction,QR Code Detection,Template Matching,Morphological Transformation,Email Notification,Depth Estimation,VLM As Classifier,Single-Label Classification Model,Image Slicer,Model Comparison Visualization,Instance Segmentation Model,Image Blur,Google Gemini,Clip Comparison,VLM As Detector,Seg Preview,OpenAI,Halo Visualization,ByteTrack Tracker,Roboflow Dataset Upload,Motion Detection,Google Vision OCR
Input and Output Bindings¶
The available connections depend on its binding kinds. Check what binding kinds
Heatmap Visualization in version v1 has.
Bindings
-
input
image(image): The image to visualize on..copy_image(boolean): Enable this option to create a copy of the input image for visualization, preserving the original. Use this when stacking multiple visualizations..predictions(Union[rle_instance_segmentation_prediction,keypoint_detection_prediction,instance_segmentation_prediction,object_detection_prediction]): Model predictions to visualize..metadata(video_metadata): Video metadata containing video_identifier to maintain separate state for different videos..position(string): The position of the heatmap relative to the detection..opacity(float): Opacity of the overlay mask, between 0 and 1..radius(integer): Radius of the heat circle..kernel_size(integer): Kernel size for blurring the heatmap..top_hue(integer): Hue at the top of the heatmap. Defaults to 0 (red)..low_hue(integer): Hue at the bottom of the heatmap. Defaults to 125 (blue)..ignore_stationary(boolean): If True, only moving objects (based on tracker ID) will contribute to the heatmap..motion_threshold(integer): Minimum movement in pixels required to consider an object as moving..
-
output
image(image): Image in workflows.
Example JSON definition of step Heatmap Visualization in version v1
{
"name": "<your_step_name_here>",
"type": "roboflow_core/heatmap_visualization@v1",
"image": "$inputs.image",
"copy_image": true,
"predictions": "$steps.object_detection_model.predictions",
"metadata": "$inputs.video_metadata",
"position": "BOTTOM_CENTER",
"opacity": 0.2,
"radius": 40,
"kernel_size": 25,
"top_hue": 0,
"low_hue": 125,
"ignore_stationary": true,
"motion_threshold": 25
}