Crate chess_corners_core 

Core primitives for computing ChESS responses and extracting subpixel corners.

The crate is organized along the three orthogonal axes the detector pipeline composes:

Module	Description
detect	Feature-detection pipelines. Two independent families share a common output type: detect::chess (ChESS response + NMS) and detect::radon (Radon SAT + peak detection).
refine	Pluggable subpixel-refinement backends. The refine::CornerRefiner trait dispatches across center-of-mass, Förstner, saddle-point, and Radon-peak refiners.
orientation	Two-axis orientation fit (OrientationMethod::RingFit ring fit, OrientationMethod::DiskFit full-disk crossing-line) shared between detectors. The orientation::describe_corners entry point produces CornerDescriptor values with subpixel position, two-axis orientation, per-axis 1σ uncertainty, contrast, and fit residual.
imageview	Zero-copy ImageView into a borrowed grayscale buffer, with optional origin offset for pyramid/ROI support.

Most users should work through the chess-corners facade crate rather than depending on chess-corners-core directly. Depend on this crate only when you need raw response maps, custom refiners, or the Radon detector primitives.

Features

• std (default) – enables use of the Rust standard library. When disabled, the crate is no_std + alloc.
• rayon – parallelizes the dense response computation and Radon accumulation over image rows using the rayon crate. Does not change numerical results.
• simd – enables a SIMD‑accelerated inner loop for the ChESS response kernel, based on portable_simd. Requires a nightly compiler; the scalar path remains the reference implementation.
• tracing – emits structured spans around response and detector functions using the tracing ecosystem, useful for profiling and diagnostics.

Feature combinations:

• no features / std only – single‑threaded scalar implementation.
• rayon – same scalar math, but rows are processed in parallel.
• simd – single‑threaded, but the inner ring computation is vectorized.
• rayon + simd – rows are processed in parallel and each row uses the SIMD‑accelerated inner loop.

The detector in detect is independent of rayon/simd, and tracing only adds observability; none of these features change the numerical results, only performance and instrumentation.

The ChESS idea is proposed in Bennett, Lasenby, ChESS: A Fast and Accurate Chessboard Corner Detector, CVIU 2014.

Re-exports

pub use crate::detect::dense::ChessBuffers;

pub use crate::detect::dense::ChessDetector;

pub use crate::detect::dense::DenseDetector;

pub use crate::detect::dense::RadonDetector;

pub use crate::detect::radon::primitives::fit_peak_frac;

pub use crate::detect::radon::primitives::PeakFitMode;

pub use crate::detect::radon::detect_peaks_from_radon;

pub use crate::detect::radon::radon_response_u8;

pub use crate::detect::radon::RadonBuffers;

pub use crate::detect::radon::RadonDetectorParams;

pub use crate::detect::radon::RadonResponseView;

pub use crate::detect::radon::SatElem;

pub use crate::detect::AxisEstimate;

pub use crate::detect::Corner;

pub use crate::detect::CornerDescriptor;

pub use crate::orientation::fit_axes_at_point;

pub use crate::orientation::fit_axes_from_samples;

pub use crate::orientation::AxisFitResult;

pub use crate::orientation::OrientationMethod;

pub use crate::refine::CenterOfMassConfig;

pub use crate::refine::CenterOfMassRefiner;

pub use crate::refine::CornerRefiner;

pub use crate::refine::ForstnerConfig;

pub use crate::refine::ForstnerRefiner;

pub use crate::refine::RadonPeakConfig;

pub use crate::refine::RadonPeakRefiner;

pub use crate::refine::RefineContext;

pub use crate::refine::RefineResult;

pub use crate::refine::RefineStatus;

pub use crate::refine::Refiner;

pub use crate::refine::RefinerKind;

pub use crate::refine::SaddlePointConfig;

pub use crate::refine::SaddlePointRefiner;

pub use imageview::ImageView;

Modules

detect

Feature-detection pipelines.

imageview

orientation

Two-axis projective orientation fit at a chessboard corner.

refine

Pluggable subpixel-refinement backends.

Structs

ChessParams

Tunable parameters for the ChESS response computation and corner detection.

ResponseMap

Dense response map in row-major layout.