object_detection_lambda / lambda_function.py
Clement Vachet
Improve code based on pylint and black suggestions
67f4974
"""
AWS Lambda function
"""
import base64
import json
import logging
from detection import ml_detection, ml_utils
logger = logging.getLogger()
logger.setLevel(logging.INFO)
# Find ML model type based on string request
def get_model_type(query_string):
"""Find ML model type based on string request"""
# Default ml model type
if query_string == "":
model_type = "facebook/detr-resnet-50"
# Assess query string value
elif "detr" in query_string:
model_type = "facebook/" + query_string
elif "yolos" in query_string:
model_type = "hustvl/" + query_string
else:
raise Exception("Incorrect model type.")
return model_type
# Run detection pipeline: load ML model, perform object detection and return json object
def detection_pipeline(model_type, image_bytes):
"""detection pipeline: load ML model, perform object detection and return json object"""
# Load correct ML model
processor, model = ml_detection.load_model(model_type)
# Perform object detection
results = ml_detection.object_detection(processor, model, image_bytes)
# Convert dictionary of tensors to JSON object
result_json_dict = ml_utils.convert_tensor_dict_to_json(results)
return result_json_dict
def lambda_handler(event, context):
"""
Lambda handler (proxy integration option unchecked on AWS API Gateway)
Args:
event (dict): The event that triggered the Lambda function.
context (LambdaContext): Information about the execution environment.
Returns:
dict: The response to be returned from the Lambda function.
"""
# logger.info(f"API event: {event}")
try:
# Retrieve model type
model_query = event.get("model", "")
model_type = get_model_type(model_query)
logger.info("Model query: %s", model_query)
logger.info("Model type: %s", model_type)
# Decode the base64-encoded image data from the event
image_data = event["body"]
if event["isBase64Encoded"]:
image_data = base64.b64decode(image_data)
# Run detection pipeline
result_dict = detection_pipeline(model_type, image_data)
logger.info("API Results: %s", str(result_dict))
return {
"statusCode": 200,
"headers": {"Content-Type": "application/json"},
"body": json.dumps(result_dict),
}
except Exception as e:
logger.info("API Error: %s", str(e))
return {
"statusCode": 500,
"headers": {"Content-Type": "application/json"},
"body": json.dumps({"error": str(e)}),
}