Nodes and Components

This package includes a number of ROS 2 components that can be assembled into depth image processing pipelines. See the tutorial Launching depth_image_proc Components.

Alternatively, each component can be run as a standalone node.

depth_image_proc::ConvertMetricNode

Component to convert raw uint16 depth image in millimeters to float depth image in meters. Also available as a standalone node with the name convert_metric_node.

Subscribed Topics

  • image_raw (sensor_msgs/Image): uint16 depth image in millimeters, the native OpenNI format.

Published Topics

  • image (sensor_msgs/Image): float depth image in meters, the recommended format for processing in ROS 2.

Parameters

  • image_transport (string, default: raw): Image transport to use.

depth_image_proc::CropForemostNode

Takes a depth image and crops the closest element. The node will find the minimum depth value in the image and then set all pixels farther than min + distance to 0. Also available as a standalone node crop_foremost_node.

Subscribed Topics

  • image_raw (sensor_msgs/Image): Must be a depth (single channel) image.

Published Topics

  • image (sensor_msgs/Image): Cropped image.

Parameters

  • distance (float, default: 0.0): The depth tolerance to use when thresholding the image. Pixels farther than min + distance will be set to 0.

  • image_transport (string, default: raw): Image transport to use.

depth_image_proc::DisparityNode

Converts a depth image to disparity image. Also available as a standalone node disparity_node. The images below show the raw depth image, and the output disparity image. The output disparity image is being colorized using the disparity_view node from the image_view package.

depth disparity

Subscribed Topics

  • left/image_rect (sensor_msgs/Image): Rectified depth image.

  • right/camera_info (sensor_msgs/CameraInfo): Camera calibration and metadata. Must contain the baseline, which conventionally is encoded in the right camera P matrix.

Published Topics

  • left/disparity (stereo_msgs/DisparityImage): Disparity image (inversely related to depth), for interop with stereo processing nodes. For all other purposes use depth images instead.

Parameters

  • delta_d (double, default: 0.125): Smallest allowed disparity increment, which relates to the achievable depth range resolution. Defaults to 1/8 pixel.

  • image_transport (string, default: raw): Image transport to use.

  • min_range (double, default: 0.0): Minimum detectable distance.

  • max_range (double, default: +Inf): Maximum detectable distance.

  • queue_size (int, default: 5): Size of message queue for synchronizing subscribed topics.

depth_image_proc::PointCloudXyzNode

Converts a depth image to XYZ point cloud. Also available as a standalone node point_cloud_xyz_node. The images below show the raw depth image, and the output point cloud, colorized along the Z-axis.

depth cloud_xyz

Subscribed Topics

  • image_rect (sensor_msgs/Image): Rectified depth image.

  • camera_info (sensor_msgs/CameraInfo): Camera calibration and metadata.

Published Topics

  • points (sensor_msgs/PointCloud2): XYZ point cloud. If using PCL, subscribe as PointCloud<PointXYZ>.

Parameters

  • depth_image_transport (string, default: raw): Image transport to use for the depth topic subscriber.

  • queue_size (int, default: 5): Size of message queue for synchronizing subscribed topics.

  • invalid_depth (double, default: 0.0): Value used for replacing invalid depth values (if 0.0 the parameter has no effect).

depth_image_proc::PointCloudXyzRadialNode

Converts a radial depth image to an XYZ point cloud. Note that radial nodes assume an unrectified radial image, and therefore use the K and D matrices of the camera info message, rather than the P matrix. Also available as a standalone node point_cloud_xyz_radial_node.

Subscribed Topics

  • depth/image_raw (sensor_msgs/Image): Unrectified radial depth image.

  • depth/camera_info (sensor_msgs/CameraInfo): Camera calibration and metadata.

Published Topics

  • points (sensor_msgs/PointCloud2): XYZ point cloud. If using PCL, subscribe as PointCloud<PointXYZ>.

Parameters

  • depth_image_transport (string, default: raw): Image transport to use for the depth topic subscriber.

  • queue_size (int, default: 5): Size of message queue for synchronizing subscribed topics.

depth_image_proc::PointCloudXyziNode

Component to convert depth image to XYZI point cloud. Also available as a standalone node point_cloud_xyzi_node.

Subscribed Topics

  • depth/image_rect (sensor_msgs/Image): Rectified depth image.

  • intensity/image_rect (sensor_msgs/Image): Rectified intensity image.

  • intensity/camera_info (sensor_msgs/CameraInfo): Camera calibration and metadata.

Published Topics

  • points (sensor_msgs/PointCloud2): XYZ point cloud. If using PCL, subscribe as PointCloud<PointXYZI>.

Parameters

  • depth_image_transport (string, default: raw): Image transport to use for the depth topic subscriber.

  • image_transport (string, default: raw): Image transport to use for the intensity image subscriber.

  • queue_size (int, default: 5): Size of message queue for synchronizing subscribed topics.

  • invalid_depth (double, default: 0.0): Value used for replacing invalid depth values (if 0.0 the parameter has no effect).

depth_image_proc::PointCloudXyziRadialNode

Converts a radial depth image and an intensity image to an XYZI point cloud. Note that radial nodes assume an unrectified radial image, and therefore use the K and D matrices of the camera info message, rather than the P matrix. Also available as a standalone node point_cloud_xyzi_radial_node.

Subscribed Topics

  • depth/image_raw (sensor_msgs/Image): Unrectified radial depth image.

  • intensity/image_raw (sensor_msgs/Image): Unrectified intensity image.

  • intensity/camera_info (sensor_msgs/CameraInfo): Camera calibration and metadata.

Published Topics

  • points (sensor_msgs/PointCloud2): XYZI point cloud. If using PCL, subscribe as PointCloud<PointXYZI>.

Parameters

  • depth_image_transport (string, default: raw): Image transport to use for the depth topic subscriber.

  • image_transport (string, default: raw): Image transport to use for the intensity image subscriber.

  • queue_size (int, default: 5): Size of message queue for synchronizing subscribed topics.

depth_image_proc::PointCloudXyzrgbNode

Combines a registered depth image and an RGB image into XYZRGB point cloud. Also available as a standalone node point_cloud_xyzrgb_node.

depth_reg rgb

The node can convert the registered depth and rgb images (above) into a colorized point cloud (below):

cloud_xyzrgb

Subscribed Topics

  • depth_registered/image_rect (sensor_msgs/Image): Rectified depth image, registered to the RGB camera

  • rgb/image_rect_color (sensor_msgs/Image): Rectified color image.

  • rgb/camera_info (sensor_msgs/CameraInfo): RGB camera calibration and metadata.

Published Topics

  • points (sensor_msgs/PointCloud2): XYZ point cloud. If using PCL, subscribe as PointCloud<PointXYZRGB>.

Parameters

  • depth_image_transport (string, default: raw): Image transport to use for depth_registered subscriber.

  • image_transport (string, default: raw): Image transport to use for rgb/image_rect_color subscriber.

  • exact_sync (bool, default: False): Whether to use exact synchronizer.

  • queue_size (int, default: 5): Size of message queue for synchronizing subscribed topics.

  • invalid_depth (double, default: 0.0): Value used for replacing invalid depth values (if 0.0 the parameter has no effect).

depth_image_proc::PointCloudXyzrgbRadialNode

Converts a radial depth image and an rgb image to an XYZRGB point cloud. Note that radial nodes assume an unrectified radial image, and therefore use the K and D matrices of the camera info message, rather than the P matrix. Also available as a standalone node point_cloud_xyzrgb_radial_node.

Subscribed Topics

  • depth/image_raw (sensor_msgs/Image): Unrectified radial depth image.

  • rgb/image_raw (sensor_msgs/Image): Unrectified rgb image.

  • rgb/camera_info (sensor_msgs/CameraInfo): Camera calibration and metadata.

Published Topics

  • points (sensor_msgs/PointCloud2): XYZRGB point cloud. If using PCL, subscribe as PointCloud<PointXYZRGB>.

Parameters

  • depth_image_transport (string, default: raw): Image transport to use for the depth topic subscriber.

  • image_transport (string, default: raw): Image transport to use for the rgb image subscriber.

  • queue_size (int, default: 5): Size of message queue for synchronizing subscribed topics.

depth_image_proc::RegisterNode

Component to “register” a depth image to another camera frame. Reprojecting the depths requires the calibration parameters of both cameras and, from tf, and the extrinsic transform between them. The images below show the depth image before and after apply registration:

depth depth_reg

Subscribed Topics

  • depth/image_rect (sensor_msgs/Image): Rectified depth image. The image should be either 16UC1 (which is interpreted as millimeters) or 32FC1 (which is interpreted as meters).

  • depth/camera_info (sensor_msgs/CameraInfo): Depth camera calibration and metadata.

  • rgb/camera_info (sensor_msgs/CameraInfo): RGB camera calibration and metadata.

Published Topics

  • depth_registered/camera_info (sensor_msgs/CameraInfo): Camera calibration and metadata. Same as rgb/camera_info but time-synced to depth_registered/image_rect.

  • depth_registered/image_rect (sensor_msgs/Image): Reprojected depth image in the RGB camera frame.

Parameters

  • depth_image_transport (string, default: raw): Image transport to use for depth subscriber.

  • use_rgb_timestamp (bool, default: false) : use timestamp of rgb image instead of depth image for the registered image.

  • fill_upsampling_holes (bool, default: false) : when RGB is higher res, interpolate by rasterizing depth triangles onto the registered image.

  • queue_size (int, default: 5): Size of message queue for synchronizing subscribed topics.

Required TF Transforms

  • /depth_optical_frame → /rgb_optical_frame: The transform between the depth and RGB camera optical frames as specified in the headers of the subscribed topics (rendered here as /depth_optical_frame and /rgb_optical_frame).