query_calib_data_observ_indicesT_query_calib_data_observ_indicesquery_calib_data_observ_indicesQueryCalibDataObservIndicesQueryCalibDataObservIndices (Operator)

Name

query_calib_data_observ_indicesT_query_calib_data_observ_indicesquery_calib_data_observ_indicesQueryCalibDataObservIndicesQueryCalibDataObservIndices — Query information about the relations between cameras, calibration objects, and calibration object poses.

Signature

Description

A calibration data model (CalibDataIDCalibDataIDCalibDataIDCalibDataIDcalibDataID) contains a collection of observations, which are added to the model by set_calib_data_observ_pointsset_calib_data_observ_pointsset_calib_data_observ_pointsSetCalibDataObservPointsSetCalibDataObservPoints. Each observation is associated to an observing camera, an observed calibration object, and a calibration object pose. With the operator query_calib_data_observ_indicesquery_calib_data_observ_indicesquery_calib_data_observ_indicesQueryCalibDataObservIndicesQueryCalibDataObservIndices, you can query observation indices associated to a camera or an calibration object, depending on the parameter ItemTypeItemTypeItemTypeItemTypeitemType.

For ItemTypeItemTypeItemTypeItemTypeitemType='camera'"camera""camera""camera""camera", you must a valid camera index in ItemIdxItemIdxItemIdxItemIdxitemIdx. Then, Index1Index1Index1Index1index1 returns a list of calibration object indices and Index2Index2Index2Index2index2 returns a list of pose indices. Each pair [Index1[I],Index2[I]] represents calibration object pose that are 'observed' by camera ItemIdxItemIdxItemIdxItemIdxitemIdx.

For ItemTypeItemTypeItemTypeItemTypeitemType='calib_obj'"calib_obj""calib_obj""calib_obj""calib_obj", you must specify a valid calibration object index in ItemIdxItemIdxItemIdxItemIdxitemIdx. Then, Index1Index1Index1Index1index1 returns a list of camera indices and Index2Index2Index2Index2index2 returns a list of corresponding calibration object pose indices. Each pair [Index1[I],Index2[I]] denotes that camera Index1[I] is observing the Index2[I]th pose of calibration object ItemIdxItemIdxItemIdxItemIdxitemIdx.

This operator is particularly suitable for accessing observation data of a calibration data model whose configuration is unknown at the moment of its usage (e.g., if it was just read from a file). As a special case, this operator can be used to get the precise list of poses of one calibration object (see the example).

Attention

A camera calibration data model CalibDataID cannot be shared between two or more user's threads. Different camera calibration data models can be used independently and safely in different threads.

Parallelization

• Multithreading type: reentrant (runs in parallel with non-exclusive operators).
• Multithreading scope: global (may be called from any thread).
• Processed without parallelization.

Parameters

Example (HDevelop)

* read a calibration model from a file
read_calib_data ('calib_data.ccd',CalibDataID)

* get calibration object indices assigned to calibration object 0
query_calib_data_observ_indices (CalibDataID, 'calib_obj', 0, _, \
                                 CalibObjPoseIndices)
* CalibObjPoseIndices contains the list of pose indices of calibration
* object 0. In order to be stored in the model, each calibration object
* needs to be observed by at least one camera in the setup (a calibration
* object pose that is not observed by any camera cannot be stored in
* the model). Typically, a calibration object pose can be observed by more
* than one camera. Hence, some calibration object pose indices might appear
* repeatedly in CalibObjPoseIndices. We use tuple_sort and tuple_uniq to
* extract a unique list of calibration object pose indices for calibration
* object 0.
tuple_sort (CalibObjPoseIndices, CalibObjPoseIndices)
tuple_uniq (CalibObjPoseIndices, CalibObjPoseIndices)

* get poses of calibration objects observed by camera 2
calibrate_cameras (CalibDataID, Error)
query_calib_data_observ_indices (CalibDataID, 'camera', 2, CalibObjIndices,\
                                 CalibObjPoseIndices)
for I := 0 to |CalibObjIndices|-1 by 1
  get_calib_data (CalibDataID, 'calib_obj_pose', \
                  [CalibObjIndices[I], CalibObjPoseIndices[I]], \
                  'pose', CalobjPose)
endfor

Module

Calibration