Example Workflows - Workflows with multiple models¶
Below you can find example workflows you can use as inspiration to build your apps.
Workflow detection model followed by classifier¶
This example showcases how to stack models on top of each other - in this particular case, we detect objects using object detection models, requesting only "dogs" bounding boxes in the output of prediction.
Based on the model predictions, we take each bounding box with dog and apply dynamic cropping to be able to run classification model for each and every instance of dog separately. Please note that for each inserted image we will have nested batch of crops (with size dynamically determined in runtime, based on first model predictions) and for each crop we apply secondary model.
Secondary model is supposed to make prediction from dogs breed classifier model to assign detailed class for each dog instance.
Workflow definition
{
"version": "1.0",
"inputs": [
{
"type": "WorkflowImage",
"name": "image"
}
],
"steps": [
{
"type": "roboflow_core/roboflow_object_detection_model@v2",
"name": "general_detection",
"image": "$inputs.image",
"model_id": "yolov8n-640",
"class_filter": [
"dog"
]
},
{
"type": "roboflow_core/dynamic_crop@v1",
"name": "cropping",
"image": "$inputs.image",
"predictions": "$steps.general_detection.predictions"
},
{
"type": "roboflow_core/roboflow_classification_model@v2",
"name": "breds_classification",
"image": "$steps.cropping.crops",
"model_id": "dog-breed-xpaq6/1"
}
],
"outputs": [
{
"type": "JsonField",
"name": "predictions",
"selector": "$steps.breds_classification.predictions"
}
]
}
Workflow with classifier providing detailed labels for detected objects¶
This example illustrates how helpful Workflows could be when you have generic object detection model (capable of detecting common classes - like dogs) and specific classifier (capable of providing granular predictions for narrow high-level classes of objects - like dogs breed classifier). Having list of classifier predictions for each detected dog is not handy way of dealing with output - as you kind of loose the information about location of specific dog. To avoid this problem, you may want to replace class labels of original bounding boxes (from the first model localising dogs) with classes predicted by classifier.
In this example, we use Detections Classes Replacement block which is also interesting from the
perspective of difference of its inputs dimensionality levels. object_detection_predictions input
has level 1 (there is one prediction with bboxes for each input image) and classification_predictions
has level 2 (there are bunch of classification results for each input image). The block combines that
two inputs and produces result at dimensionality level 1 - exactly the same as predictions from
object detection model.
Workflow definition
{
"version": "1.0",
"inputs": [
{
"type": "WorkflowImage",
"name": "image"
}
],
"steps": [
{
"type": "ObjectDetectionModel",
"name": "general_detection",
"image": "$inputs.image",
"model_id": "yolov8n-640",
"class_filter": [
"dog"
]
},
{
"type": "Crop",
"name": "cropping",
"image": "$inputs.image",
"predictions": "$steps.general_detection.predictions"
},
{
"type": "ClassificationModel",
"name": "breds_classification",
"image": "$steps.cropping.crops",
"model_id": "dog-breed-xpaq6/1"
},
{
"type": "DetectionsClassesReplacement",
"name": "classes_replacement",
"object_detection_predictions": "$steps.general_detection.predictions",
"classification_predictions": "$steps.breds_classification.predictions"
}
],
"outputs": [
{
"type": "JsonField",
"name": "original_predictions",
"selector": "$steps.general_detection.predictions"
},
{
"type": "JsonField",
"name": "predictions_with_replaced_classes",
"selector": "$steps.classes_replacement.predictions"
}
]
}
Workflow presenting models ensemble¶
This workflow presents how to combine predictions from multiple models running against the same input image with the block called Detections Consensus.
First, we run two object detections models steps and we combine their predictions. Fusion may be performed in different scenarios based on Detections Consensus step configuration:
-
you may combine predictions from models detecting different objects and then require only single model vote to add predicted bounding box to the output prediction
-
you may combine predictions from models detecting the same objects and expect multiple positive votes to accept bounding box to the output prediction - this way you may improve the quality of predictions
Workflow definition
{
"version": "1.0",
"inputs": [
{
"type": "WorkflowImage",
"name": "image"
},
{
"type": "WorkflowParameter",
"name": "model_id",
"default_value": "yolov8n-640"
}
],
"steps": [
{
"type": "RoboflowObjectDetectionModel",
"name": "detection_1",
"image": "$inputs.image",
"model_id": "$inputs.model_id",
"confidence": 0.3
},
{
"type": "RoboflowObjectDetectionModel",
"name": "detection_2",
"image": "$inputs.image",
"model_id": "$inputs.model_id",
"confidence": 0.83
},
{
"type": "DetectionsConsensus",
"name": "consensus",
"predictions_batches": [
"$steps.detection_1.predictions",
"$steps.detection_2.predictions"
],
"required_votes": 2,
"required_objects": {
"person": 2
}
}
],
"outputs": [
{
"type": "JsonField",
"name": "result",
"selector": "$steps.consensus.*"
}
]
}
Comparison of detection models predictions¶
This example showcases how to compare predictions from two different models using Workflows and Model Comparison Visualization block.
Workflow definition
{
"version": "1.0",
"inputs": [
{
"type": "WorkflowImage",
"name": "image"
},
{
"type": "WorkflowParameter",
"name": "model_1",
"default_value": "yolov8n-640"
},
{
"type": "WorkflowParameter",
"name": "model_2",
"default_value": "yolov8n-1280"
}
],
"steps": [
{
"type": "roboflow_core/roboflow_object_detection_model@v2",
"name": "model",
"images": "$inputs.image",
"model_id": "$inputs.model_1"
},
{
"type": "roboflow_core/roboflow_object_detection_model@v2",
"name": "model_1",
"images": "$inputs.image",
"model_id": "$inputs.model_2"
},
{
"type": "roboflow_core/model_comparison_visualization@v1",
"name": "model_comparison_visualization",
"image": "$inputs.image",
"predictions_a": "$steps.model_1.predictions",
"predictions_b": "$steps.model.predictions"
}
],
"outputs": [
{
"type": "JsonField",
"name": "model_1_predictions",
"coordinates_system": "own",
"selector": "$steps.model.predictions"
},
{
"type": "JsonField",
"name": "model_2_predictions",
"coordinates_system": "own",
"selector": "$steps.model_1.predictions"
},
{
"type": "JsonField",
"name": "visualization",
"coordinates_system": "own",
"selector": "$steps.model_comparison_visualization.image"
}
]
}