Crate opencv_ros_camera
source ·Expand description
Geometric models of OpenCV/ROS cameras for photogrammetry
§About
This crate provides a geometric model of a camera compatible with OpenCV as
used by ROS (the Robot Operating System). The crate is in pure Rust, can be
compiled in no_std
mode, implements the
IntrinsicParameters
trait from the cam-geom
and provides
support to read and write camera models in various formats.
In greater detail:
- Compatible with camera calibrations made by the ROS
camera_calibration
package, including monocular and stereo calibrations. Despite this compatibility, does not depend on ROS or OpenCV. (Furthermore, there is also no dependency on the excellent rosrust crate). - Can be compiled without the Rust standard library or allocator to support embedded applications.
- The
RosOpenCvIntrinsics
type implements theIntrinsicParameters
trait from thecam-geom
crate. Thus, acam_geom::Camera
can be created to handle intrinsic parameters usingRosOpenCvIntrinsics
and camera pose handled by theExtrinsicParameters
struct fromcam-geom
. (See the example below.) - When compiled with the
serde-serialize
feature, read camera calibrations saved by the ROScamera_calibration/cameracalibrator.py
node in~/.ros/camera_info/camera_name.yaml
withfrom_ros_yaml
. - When compiled with the
serde-serialize
feature, read and write theRosOpenCvIntrinsics
struct using serde.
§Example - read a ROS YAML file and create a cam_geom::Camera
from it.
Let’s say we have YAML file saved by the ROS
camera_calibration/cameracalibrator.py
node. How can we create a
cam_geom::Camera
from this?
use nalgebra::{Matrix2x3, Unit, Vector3};
// Here we have the YAML file contents hardcoded in a string. Ordinarily, you
// would read this from a file such as `~/.ros/camera_info/camera_name.yaml`, but
// for this example, it is hardcoded here.
let yaml_buf = b"image_width: 659
image_height: 494
camera_name: Basler_21029382
camera_matrix:
rows: 3
cols: 3
data: [516.385667640757, 0, 339.167079537312, 0, 516.125799367807, 227.37993524141, 0, 0, 1]
distortion_model: plumb_bob
distortion_coefficients:
rows: 1
cols: 5
data: [-0.331416226762003, 0.143584747015566, 0.00314558656668844, -0.00393597842852019, 0]
rectification_matrix:
rows: 3
cols: 3
data: [1, 0, 0, 0, 1, 0, 0, 0, 1]
projection_matrix:
rows: 3
cols: 4
data: [444.369750976562, 0, 337.107817516087, 0, 0, 474.186859130859, 225.062742824321, 0, 0, 0, 1, 0]";
// The ROS YAML file does not contain the pose (no extrinsic parameters). Here we
// specify them directly. The camera is at (10,0,0), looking at (0,0,0), with up (0,0,1).
let camcenter = Vector3::new(10.0, 0.0, 0.0);
let lookat = Vector3::new(0.0, 0.0, 0.0);
let up = Unit::new_normalize(Vector3::new(0.0, 0.0, 1.0));
let pose = cam_geom::ExtrinsicParameters::from_view(&camcenter, &lookat, &up);
// We need the `serde-serialize` feature for the `from_ros_yaml` function.
#[cfg(feature = "serde-serialize")]
{
let from_ros = opencv_ros_camera::from_ros_yaml(&yaml_buf[..]).unwrap();
// Finally, create camera from intrinsic and extrinsic parameters.
let camera = cam_geom::Camera::new(from_ros.intrinsics, pose);
}
§testing
Test no_std
compilation with:
# install target with: "rustup target add thumbv7em-none-eabihf"
cargo check --no-default-features --target thumbv7em-none-eabihf
Run unit tests with:
cargo test
cargo test --features serde-serialize
serde support requires std.
§re-render README.md
cargo install cargo-readme
cargo readme > README.md
Structs§
- Specifies distortion using the Brown-Conrady “plumb bob” model.
- A struct with
RosOpenCvIntrinsics
, camera name and image sensor dimensions. - Camera calibration info as saved by ROS.
- Matrix saved by ROS.
- A perspective camera model with distortion compatible with OpenCV and ROS.
- Undistorted 2D pixel locations
Enums§
- Possible errors.
- The type defines termination criteria for iterative algorithms.
Traits§
- Extension trait to add
world_to_undistorted_pixel()
method.
Functions§
- Construct NamedIntrinsicParameters from ROS format YAML data.
Type Aliases§
- Result type