Package boofcv.abst.fiducial

Interface FiducialDetector<T extends ImageBase<T>>

All Known Subinterfaces:
FiducialTracker<T>
All Known Implementing Classes:
CalibrationFiducialDetector, ECoCheck_to_FiducialDetector, FiducialDetectorPnP, MicroQrCodeDetectorPnP, QrCodeDetectorPnP, SquareBase_to_FiducialDetector, SquareBinary_to_FiducialDetector, SquareHamming_to_FiducialDetector, SquareImage_to_FiducialDetector, Uchiya_to_FiducialDetector
public interface FiducialDetector<T extends ImageBase<T>>
Interface for detecting fiducial markers and their location in the image. Optionally, some implementations can produce a unique ID for each fiducial and their 3D pose in the world. Implementations of this interface will be detectors only, meaning that they are not trackers, meaning that each call to detect will produce identical results only dependent on the input image and not the past history.
See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    computeStability(int which, double disturbance, FiducialStability results)
    Computes metrics which represents the fiducial's pose estimate stability given its current observed state.
    void
    detect(T input)
    Detects fiducials inside the image.
    Polygon2D_F64
    getBounds(int which, @Nullable Polygon2D_F64 storage)
    Used to retrieve the bounds around a marker in the image.
    void
    getCenter(int which, Point2D_F64 location)
    Returns where in the image the fiducial is.
    boolean
    getFiducialToCamera(int which, Se3_F64 fiducialToCamera)
    Used to retrieve the transformation from the fiducial's reference frame to the camera's reference frame.
    long
    getId(int which)
    If applicable, returns the ID of the fiducial found.
    ImageType<T>
    getInputType()
    Type of input image
    @Nullable LensDistortionNarrowFOV
    getLensDistortion()
    Returns the intrinsic parameters that it
    String
    getMessage(int which)
    If applicable, returns a message associated with the fiducial.
    double
    getWidth(int which)
    Returns the width of the fiducial in world units.
    boolean
    hasID()
    If true then getId(int) returns a valid unique number
    boolean
    hasMessage()
    If true then getMessage(int) returns a valid message
    boolean
    is3D()
    If true then 3D information is available for the fiducial.
    void
    setLensDistortion(@Nullable LensDistortionNarrowFOV distortion, int width, int height)
    Specifies how to remove lens distortion from the input image and how to convert pixels into normalized image coordinates.
    int
    totalFound()
    The total number of fiducial found

  • Method Details

    • detect

      void detect(T input)
      Detects fiducials inside the image. Each call to this function only depends upon the input image. The previous calls do not affect it's outcome.
      Parameters:
      input - Input image. Not modified.

    • totalFound

      int totalFound()
      The total number of fiducial found
      Returns:
      number of targets found

    • getCenter

      void getCenter(int which, Point2D_F64 location)
      Returns where in the image the fiducial is. Typically this will be the fiducial's visual center. Note that the visual center is unlikely to be the projection of the 3D geometric center. To find the former you need to reproject it using the found fiducialToCamera.

      NOTE: The reprojected center might not be the same as the location returned here.

      Parameters:
      which - Fiducial's index
      location - (output) Storage for the transform. modified.

    • getBounds

      Polygon2D_F64 getBounds(int which, @Nullable @Nullable Polygon2D_F64 storage)
      Used to retrieve the bounds around a marker in the image. How the bounds are defined is left up the implementation. It could be a simple rectangle or it could be corner features.
      Parameters:
      which - Which fiducial.
      storage - (Optional) Storage for fiducials.
      Returns:
      Found marker. Points are owned by the caller and will not be modified in the future.

    • getId

      long getId(int which)
      If applicable, returns the ID of the fiducial found. Call hasID() to see if this function returns a valid value.
      Parameters:
      which - Detected fiducial's index
      Returns:
      ID of the fiducial

    • getMessage

      String getMessage(int which)
      If applicable, returns a message associated with the fiducial. Call hasMessage() ()} to see if this function returns a valid value.
      Parameters:
      which - Detected fiducial's index
      Returns:
      Encoded message

    • setLensDistortion

      void setLensDistortion(@Nullable @Nullable LensDistortionNarrowFOV distortion, int width, int height)
      Specifies how to remove lens distortion from the input image and how to convert pixels into normalized image coordinates.
      Parameters:
      distortion - Lens distortion model. null if you want to remove a lens distortion model that had previously been set.
      width - Input image's width.
      height - Input image's height

    • getLensDistortion

      @Nullable @Nullable LensDistortionNarrowFOV getLensDistortion()
      Returns the intrinsic parameters that it
      Returns:
      intrinsic parameters

    • computeStability

      boolean computeStability(int which, double disturbance, FiducialStability results)

      Computes metrics which represents the fiducial's pose estimate stability given its current observed state. This can be viewed as an estimate of the pose estimate's precision, but not its accuracy. These numbers are generated by perturbing landmarks (by the user provided amount) and seeing how it affects the pose estimate..

      The metrics should be considered more qualitative than quantitative since exactly how this metric is computed isn't specified and can vary depending on target type of implementation type. The results could every vary each time its called, even with the the exact same inputs.

      Parameters:
      which - Index of which fiducial the stability is being requested from
      disturbance - Amount of the applied disturbance, in pixels. Try 0.25
      results - (output) Storage for stability metrics.
      Returns:
      true if successful or false if it failed for some reason

    • getFiducialToCamera

      boolean getFiducialToCamera(int which, Se3_F64 fiducialToCamera)
      Used to retrieve the transformation from the fiducial's reference frame to the camera's reference frame.
      Parameters:
      which - Fiducial's index
      fiducialToCamera - (output) Storage for the transform. modified.
      Returns:
      true if could estimate the location or false if it couldn't

    • getWidth

      double getWidth(int which)
      Returns the width of the fiducial in world units. If not square then it returns a reasonable approximation. Intended for use in visualization and not precise calculations.
      Parameters:
      which - Fiducial's index
      Returns:
      Fiducial's width.

    • is3D

      boolean is3D()
      If true then 3D information is available for the fiducial. In general a len distortion model must be provided by invoking setLensDistortion(LensDistortionNarrowFOV, int, int). The following functions are then enabled:
      1. computeStability(int, double, boofcv.abst.fiducial.FiducialStability)
      2. getFiducialToCamera(int, georegression.struct.se.Se3_F64)

    • hasID

      boolean hasID()
      If true then getId(int) returns a valid unique number
      Returns:
      boolean

    • hasMessage

      boolean hasMessage()
      If true then getMessage(int) returns a valid message
      Returns:
      boolean

    • getInputType

      ImageType<T> getInputType()
      Type of input image