Operator Reference
query_calib_data_observ_indices (Operator)
query_calib_data_observ_indices — Query information about the relations between cameras, calibration objects,
and calibration object poses.
Signature
query_calib_data_observ_indices( : : CalibDataID, ItemType, ItemIdx : Index1, Index2)
Description
A calibration data model (CalibDataID) contains a collection of
observations, which are added to the model by
set_calib_data_observ_points. Each observation is associated
to an observing camera, an observed calibration object, and a calibration
object pose. With the operator query_calib_data_observ_indices, you
can query observation indices associated to a camera or an calibration
object, depending on the parameter ItemType.
For ItemType='camera', you must pass a
valid camera index in ItemIdx. Then, Index1 returns
a list of calibration object indices and Index2 returns a
list of pose indices. Each pair [Index1[I],Index2[I]]
represents calibration object pose that are 'observed' by camera
ItemIdx.
For ItemType='calib_obj', you must specify
a valid calibration object index in ItemIdx. Then,
Index1 returns a list of camera indices and Index2 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
ItemIdx.
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).
Execution Information
- Multithreading type: reentrant (runs in parallel with non-exclusive operators).
- Multithreading scope: global (may be called from any thread).
- Processed without parallelization.
This operator modifies the state of the following input parameter:
During execution of this operator, access to the value of this parameter must be synchronized if it is used across multiple threads.
Parameters
CalibDataID (input_control, state is modified) calib_data → (handle)
Handle of a calibration data model.
ItemType (input_control) string → (string)
Kind of referred object.
Default: 'camera'
List of values: 'calib_obj', 'camera'
ItemIdx (input_control) number → (integer)
Camera index or calibration object index
(depending on the selected ItemType).
Default: 0
Suggested values: 0, 1, 2
Index1 (output_control) number-array → (integer)
List of calibration object indices or list of
camera indices (depending on ItemType).
Index2 (output_control) number-array → (integer)
Calibration object numbers.
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', CalibObjPose)
endfor
Module
Calibration