photonlibpy.estimation.openCVHelp

OpenCVHelp

rVecToRotation(rvecInput) staticmethod

Returns a 3d rotation from this :class:.Mat. The opencv rvec Mat is a vector with three elements representing the axis scaled by the angle in the EDN coordinate system. (angle = norm, and axis = rvec / norm)

Parameters:

Name	Type	Description	Default
rvecInput	ndarray	The rvec to create a Rotation3d from	required

reorderCircular(elements, backwards, shiftStart) staticmethod

Reorders the list, optionally indexing backwards and wrapping around to the last element after the first, and shifting all indices in the direction of indexing.

e.g.

({1,2,3}, false, 1) == {2,3,1}

({1,2,3}, true, 0) == {1,3,2}

({1,2,3}, true, 1) == {3,2,1}

Parameters:

Name	Type	Description	Default
elements	list[Any] | ndarray	list elements	required
backwards	bool	If indexing should happen in reverse (0, size-1, size-2, ...)	required
shiftStart	int	How much the initial index should be shifted (instead of starting at index 0, start at shiftStart, negated if backwards)	required

Returns:

Type	Description
list[Any]	Reordered list

rotationEDNToNWU(rot) staticmethod

Convert a rotation delta from NWU to EDN. For example, if you have a rotation X,Y,Z {1, 0, 0} in NWU, this would be {0, 0, 1} in EDN.

rotationToRVec(rotation) staticmethod

Creates a new :class:.np.array with this 3d rotation. The opencv rvec Mat is a vector with three elements representing the axis scaled by the angle in the EDN coordinate system. (angle = norm, and axis = rvec / norm)

Parameters:

Name	Type	Description	Default
rotation	Rotation3d	The rotation to convert into a np.array	required

solvePNP_SQPNP(cameraMatrix, distCoeffs, modelTrls, imagePoints) staticmethod

Finds the transformation that maps the camera's pose to the origin of the supplied object. An "object" is simply a set of known 3d translations that correspond to the given 2d points. If, for example, the object translations are given relative to close-right corner of the blue alliance(the default origin), a camera-to-origin transformation is returned. If the translations are relative to a target's pose, a camera-to-target transformation is returned.

There must be at least 3 points to use this method. This does not return an alternate solution-- if you are intending to use solvePNP on a single AprilTag, see {@link

solvePNP_SQUARE} instead.

Parameters:

Name	Type	Description	Default
cameraMatrix	ndarray	The camera intrinsics matrix in standard opencv form	required
distCoeffs	ndarray	The camera distortion matrix in standard opencv form	required
objectTrls		The translations of the object corners, relative to the field.	required
imagePoints	ndarray	The projection of these 3d object points into the 2d camera image. The order should match the given object point translations.	required

Returns:

Type	Description
PnpResult | None	The resulting transformation that maps the camera pose to the target pose. If the 3d model points are supplied relative to the origin, this transformation brings the camera to the origin.

solvePNP_Square(cameraMatrix, distCoeffs, modelTrls, imagePoints) staticmethod

Finds the transformation(s) that map the camera's pose to the target's pose. The camera's pose relative to the target is determined by the supplied 3d points of the target's model and their associated 2d points imaged by the camera. The supplied model translations must be relative to the target's pose.

For planar targets, there may be an alternate solution which is plausible given the 2d image points. This has an associated "ambiguity" which describes the ratio of reprojection error between the "best" and "alternate" solution.

This method is intended for use with individual AprilTags, and will not work unless 4 points are provided.

Parameters:

Name	Type	Description	Default
cameraMatrix	ndarray	The camera intrinsics matrix in standard opencv form	required
distCoeffs	ndarray	The camera distortion matrix in standard opencv form	required
modelTrls	list[Translation3d]	The translations of the object corners. These should have the object pose as their origin. These must come in a specific, pose-relative order (in NWU): - Point 0: [0, -squareLength / 2, squareLength / 2] - Point 1: [0, squareLength / 2, squareLength / 2] - Point 2: [0, squareLength / 2, -squareLength / 2] - Point 3: [0, -squareLength / 2, -squareLength / 2]	required
imagePoints	ndarray	The projection of these 3d object points into the 2d camera image. The order should match the given object point translations.	required

Returns:

Type	Description
PnpResult | None	The resulting transformation that maps the camera pose to the target pose and the ambiguity if an alternate solution is available.

tVecToTranslation(tvecInput) staticmethod

Returns a new 3d translation from this :class:.Mat. The opencv tvec is a vector with three elements representing {x, y, z} in the EDN coordinate system.

Parameters:

Name	Type	Description	Default
tvecInput	ndarray	The tvec to create a Translation3d from	required

translationEDNToNWU(trl) staticmethod

Convert a rotation delta from EDN to NWU. For example, if you have a rotation X,Y,Z {1, 0, 0} in EDN, this would be {0, -1, 0} in NWU.

translationToTVec(translations) staticmethod

Creates a new :class:np.array with these 3d translations. The opencv tvec is a vector with three elements representing {x, y, z} in the EDN coordinate system.

Parameters:

Name	Type	Description	Default
translations	list[Translation3d]	The translations to convert into a np.array	required