CedarDetect provides efficient and accurate detection of stars in sky images. Given an image, CedarDetect returns a list of detected star centroids expressed in image pixel coordinates.

Features:

• Employs localized thresholding to tolerate changes in background levels across the image.
• Adapts to different image exposure levels.
• Estimates noise in the image and adapts the star detection threshold accordingly.
• Automatically classifies and rejects hot pixels.
• Rejects trailed objects such as aircraft lights or satellites.
• Tolerates the presence of bright interlopers such as the moon, streetlights, or illuminated foreground objects.
• Simple function call interface with few parameters aside from the input image.
• Fast! On a Raspberry Pi 4B, the execution time per 1M image pixels is usually less than 10ms, even when several dozen stars are present in the image.

For more information, see the crate documentation in src/algorithm.rs.

See the sample program at src/bin/test_cedar_detect.rs for example usages of CedarDetect called directly from Rust program logic.

There is (currently) no option to link CedarDetect with Python. Instead, a microservice invocation API is provided using gRPC.

The src/bin/cedar_detect_server.rs binary runs as a gRPC service, providing a simple image → centroids RPC interface. See src/proto/cedar_detect.proto for the gRPC service definition.

In python/cedar_detect_client.py, a simple Python script demonstrates how to invoke CedarDetect using its gRPC server. This program reads some test images, uses CedarDetect to find centroids, and then plate-solves these centroids using Tetra3.

To try it out:

0. Install Python and all needed dependencies.

1. Install Tetra3.

2. With python/ as your current directory, execute:

    python -m grpc_tools.protoc -I../src/proto --python_out=. --pyi_out=. --grpc_python_out=. ../src/proto/cedar_detect.proto
   

3. Run the CedarDetect gRPC server in background:

    cargo run --release --bin cedar-detect-server &
   

4. Run the python program:

    python cedar_detect_client.py
   

Any language that can be a gRPC client should be able to invoke CedarDetect.