cvtkit.camera
Pose File Formats
Please see the resources page on pose file formats to learn more about the expected/supported formats commonly used in this library.
A suite of common camera utilities.
This module includes several functions for manipulating and extracting information from camera intrinsics and extrinsics, as well as converting between specific formats.
build_o3d_traj(poses, K, width, height)
Converts an array of camera poses and an intrinsics matrix into Open3D trajectory format.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
poses
|
ndarray
|
Nx4x4 array of camera pose in world-to-camera format. |
required |
K
|
ndarray
|
3x3 camera intrinsics matrix. |
required |
width
|
int
|
Expected image width. |
required |
height
|
int
|
Expected image height. |
required |
Returns:
| Type | Description |
|---|---|
PinholeCameraTrajectory
|
Open3D camera trajectory model. |
camera_center(P)
Computes the center of a camera in world coordinates.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
P
|
NDArray[Any] | Tensor
|
The extrinsics matrix (4x4) of a given camera in world-to-camera format. |
required |
Returns:
| Type | Description |
|---|---|
NDArray[Any] | Tensor
|
The camera center vector (3x1) in world coordinates. |
compute_baselines(poses)
Computes the minimum and maximum baseline between a reference camera pose (poses[0]) and a cluster of supporting camera poses (poses[1:]).
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
poses
|
NDArray[Any] | Tensor
|
Array of camera poses (Nx4x4) |
required |
Returns:
| Type | Description |
|---|---|
Tuple[float, float]
|
A tuple of baselines where the first element is the minimum baseline and the second element is the maximum baseline. |
crop_intrinsics(K, crop_row, crop_col)
Adjusts intrinsics matrix principle point coordinates corresponding to image cropping.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
K
|
NDArray[Any] | Tensor
|
3x3 camera intrinsics matrix. |
required |
crop_row
|
int
|
Offset for cy (corresponding to cropping the left and right side of an image by 'crop_row'). |
required |
crop_col
|
int
|
Offset for cx (corresponding to cropping the top and bottom side of an image by 'crop_col'). |
required |
Returns:
| Type | Description |
|---|---|
NDArray[Any] | Tensor
|
The updated 3x3 intrinsics matrix |
intrinsic_pyramid(K, levels)
Computes camera intrinsics pyramid corresonding to several levels of image downsampling.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
K
|
NDArray[Any] | Tensor
|
[Batch x 3 x 3] camera intrinsics matrix. |
required |
levels
|
int
|
The number of pyramid levels to compute. |
required |
Returns:
| Type | Description |
|---|---|
NDArray[Any] | Tensor
|
The intrinsics pyramid of shape [Batch x L x 3 x 3] in descending order. |
NDArray[Any] | Tensor
|
(L=0 corresponds to the largest image resolution). |
scale_intrinsics(K, scale)
Adjust intrinsics matrix focal length and principle point corresponding to image scaling.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
K
|
NDArray[Any] | Tensor
|
Batchx3x3 camera intrinsics matrices. |
required |
scale
|
float
|
Scale amount (i.e. scale=0.5 corresponds to scaling an image by a factor of 1/2). |
required |
Returns:
| Type | Description |
|---|---|
NDArray[Any] | Tensor
|
The updated 3x3 intrinsics matrix. |
tensor_null_space(A)
Computes the null space of a PyTorch tensor.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
A
|
Tensor
|
PyTorch tensor of shape m x n. |
required |
Returns:
| Type | Description |
|---|---|
Tensor
|
The null space of tensor A. |
to_opengl_pose(pose)
OpenGL pose: (right-up-back) (cam-to-world)
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
pose
|
NDArray[Any] | Tensor
|
The pose in non-OpenGL format |
required |
Returns:
| Type | Description |
|---|---|
NDArray[Any] | Tensor
|
Camera pose in OpenGL format. |