Trait ProblemType 

pub trait ProblemType: Sized + 'static {
    type Config: Clone + Default + Serialize + DeserializeOwned + Debug;
    type Input: Clone + Serialize + DeserializeOwned + Debug;
    type State: Clone + Default + Serialize + DeserializeOwned + Debug;
    type Output: Clone + Serialize + DeserializeOwned + Debug;
    type Export: Clone + Serialize + DeserializeOwned + Debug;

    // Required methods
    fn name() -> &'static str;
    fn export(
        output: &Self::Output,
        config: &Self::Config,
    ) -> Result<Self::Export, Error>;

    // Provided methods
    fn schema_version() -> u32 { ... }
    fn validate_input(_input: &Self::Input) -> Result<(), Error> { ... }
    fn validate_config(_config: &Self::Config) -> Result<(), Error> { ... }
    fn validate_input_config(
        _input: &Self::Input,
        _config: &Self::Config,
    ) -> Result<(), Error> { ... }
    fn on_input_change() -> InvalidationPolicy { ... }
    fn on_config_change() -> InvalidationPolicy { ... }
}

Trait defining the interface for a calibration problem.

Each problem type (e.g., planar intrinsics, hand-eye, laserline) implements this trait to specify its configuration, input data, internal state, output, and export formats.

Design Philosophy

The trait is minimal by design. Problem-specific behavior is implemented via step functions that operate on &mut CalibrationSession<Self> rather than as trait methods. This allows:

• Arbitrary step signatures with step-specific options
• Easy composition of custom pipelines
• Direct access to intermediate state

Associated Types

• Config: Calibration parameters (solver options, fix masks, thresholds)
• Input: Observation data (image points, correspondences)
• State: Problem-specific intermediate results (homographies, initial poses)
• Output: Final calibration result (camera parameters, errors)
• Export: User-facing export format (may be same as Output)

Example

pub struct MyProblem;

impl ProblemType for MyProblem {
    type Config = MyConfig;
    type Input = MyDataset;
    type State = MyState;
    type Output = MyResult;
    type Export = MyExport;

    fn name() -> &'static str { "my_problem" }

    fn export(output: &Self::Output, _config: &Self::Config) -> Result<Self::Export, crate::Error> {
        Ok(output.into())
    }
}

Required Associated Types

type Config: Clone + Default + Serialize + DeserializeOwned + Debug

Configuration parameters that control calibration behavior.

Examples: solver options, fix masks, convergence thresholds. Must have a sensible Default implementation.

type Input: Clone + Serialize + DeserializeOwned + Debug

Input observations (embedded in session).

Examples: PlanarDataset, HandEyeDataset, LaserlineDataset.

type State: Clone + Default + Serialize + DeserializeOwned + Debug

Problem-specific workspace for intermediate results.

Examples: computed homographies, initial poses, per-view residuals. Use () if no intermediate state is needed.

type Output: Clone + Serialize + DeserializeOwned + Debug

Final calibration output (single result).

Examples: PlanarIntrinsicsEstimate, HandEyeEstimate.

type Export: Clone + Serialize + DeserializeOwned + Debug

Export format for external consumption.

May be the same as Output, or a simplified/transformed version suitable for downstream use.

Required Methods

fn name() -> &'static str

Unique identifier for this problem type.

Used for serialization, logging, and identifying session files. Should be a stable, lowercase, snake_case string.

Examples: "planar_intrinsics", "hand_eye", "laserline_bundle".

fn export( output: &Self::Output, config: &Self::Config, ) -> Result<Self::Export, Error>

Convert output to export format.

Called by CalibrationSession::export. The config is provided for cases where export format depends on settings.

Provided Methods

fn schema_version() -> u32

Schema version for forward compatibility.

Bump when the serialization format of any associated type changes in a way that breaks backward compatibility.

The session loader validates this value strictly and rejects sessions whose metadata schema version differs from the current implementation.

fn validate_input(_input: &Self::Input) -> Result<(), Error>

Validate input data after setting.

Called by CalibrationSession::set_input. Return an error to reject the input.

Default implementation: always valid.

fn validate_config(_config: &Self::Config) -> Result<(), Error>

Validate configuration.

Called by CalibrationSession::set_config. Return an error to reject the config.

Default implementation: always valid.

fn validate_input_config( _input: &Self::Input, _config: &Self::Config, ) -> Result<(), Error>

Cross-validate input and config together.

Called by CalibrationSession::validate after individual validation passes.

Default implementation: always valid.

fn on_input_change() -> InvalidationPolicy

Policy for what to clear when input changes.

Default: clear state and output, keep exports.

fn on_config_change() -> InvalidationPolicy

Policy for what to clear when config changes.

Default: keep everything (config changes don’t auto-invalidate).

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl ProblemType for LaserlineDeviceProblem

type Config = LaserlineDeviceConfig

type Input = Vec<View<LaserlineMeta>>

type State = LaserlineDeviceState

type Output = LaserlineDeviceOutput

type Export = LaserlineDeviceExport

impl ProblemType for PlanarIntrinsicsProblem

type Config = PlanarIntrinsicsConfig

type Input = PlanarDataset

type State = PlanarState

type Output = PlanarIntrinsicsEstimate

type Export = PlanarIntrinsicsExport

impl ProblemType for RigExtrinsicsProblem

type Config = RigExtrinsicsConfig

type Input = RigDataset<NoMeta>

type State = RigExtrinsicsState

type Output = RigExtrinsicsEstimate

type Export = RigExtrinsicsExport

impl ProblemType for RigHandeyeProblem

type Config = RigHandeyeConfig

type Input = RigDataset<RobotPoseMeta>

type State = RigHandeyeState

type Output = HandEyeEstimate

type Export = RigHandeyeExport

impl ProblemType for ScheimpflugIntrinsicsProblem

type Config = ScheimpflugIntrinsicsConfig

type Input = PlanarDataset

type State = ScheimpflugIntrinsicsState

type Output = ScheimpflugIntrinsicsResult

type Export = ScheimpflugIntrinsicsExport

impl ProblemType for SingleCamHandeyeProblem

type Config = SingleCamHandeyeConfig

type Input = SingleCamHandeyeInput

type State = SingleCamHandeyeState

type Output = HandEyeEstimate

type Export = SingleCamHandeyeExport