Depth From Stereo
voxl-dfs-server is a background systemd service that subscribes to a stereo image feed and outputs depth information via three MPA pipes: dfs_disparity, dfs_disparity_scaled, and dfs_point_cloud.
Table of contents
Output Format
The data format is unique to each output pipe:
dfs_disparity: Grayscale image with pixel values corresponding to calculated disparity. Each pixel will be within the range [0, n_disparity_levels], which can be changed in the configuration file.
dfs_disparity_scaled: Grayscale image as above, but pixel values will correspond to scaled disparity values in the range of [0, 255].
dfs_point_cloud: An XYZ pointcloud (as specified by libmodal_pipe in modal_pipe_interfaces.h) with the reprojected distances.
For an example of how to read this data, see voxl-inspect-points.
Configuration
APQ8096 (VOXL1) and QRB5165 (VOXL2) based platforms have different implementations of the DFS algorithm. See the following child pages for platform-specific configuration.
Visualization Options
You can view either the regular disparity or scaled image streams as another normal camera pipe. As such, it can be viewed with voxl-portal, converted to ROS with voxl_mpa_to_ros, and logged to disk with voxl-logger.
The pointcloud can be viewed with voxl-portal.