This repo contains four related ros nodes-
- image_undistort_node: Undistorts and changes images intrinsics and resolution.
- stereo_info_node: Calculates the camera information needed for stereo rectification.
- stereo_undistort_node: Combines the functionality of the above two nodes to perform stereo image rectification.
- dense_stereo_node: Performs dense stereo estimation.
#image_undistort_node: A simple node for undistorting images. Handles plumb bob (aka radial-tangential), fov and equidistant distortion models. It can either use standard ros camera_info topics or load camera models in a form that is compatible with the camchain.yaml files produced by Kalibr. Note this node can also be run as a nodelet named image_undistort/ImageUndistort
##The node has several possible use cases:
- Undistort images. The default usage of the node, outputting an undistorted version of an input image.
- Modify the image resolution and intrinsics. The node supports projecting from and to any valid projection matrix and resolution.
- Provide a camera_info topic for an image. In this mode ros params are used to build a camera info message that is published in sync with the image messages. This allows the use of ros nodes that require camera info with devices and bags that do not provide it.
##Parameters:
- queue size The length of the queues the node uses for topics (default: 100).
- input_camera_info_from_ros_params If false the node will subscribe to a camera_info ros topic named input/camera_info to obtain the input camera parameters. If false the input camera parameters will be loaded from ros parameters. See the parameters format section for further details. (default: false).
- output_camera_info_source The source to use when obtaining the output camera parameters. The possible case-insensitive options are,
- "auto_generated" The default value. In this mode "good" output parameters are automatically generated based on the input image. focal length is the average of fx and fy of the input, the center point is in the center of the image, R=I and translation is preserved. Resolution is set to the largest area that contains no empty pixels. The size of the output can also be modified with the scale parameter.
- "match_input" The output projection matrix and resolution, exactly match the inputs.
- "ros_params" The output camera parameters are loaded from ros parameters. See the parameters format section for further details.
- "camera_info" The output parameters are found through subscribing to a camera_info ros topic named output/camera_info
- input_camera_namespace If the input camera parameters are loaded from ros parameters this is the namespace that will be searched. This is needed to allow both input and output to be loaded from parameters. (default: "input_camera")
- output_camera_namespace If the output camera parameters are loaded from ros parameters this is the namespace that will be searched. (default: "output_camera").
- process_images True to output a processed image, false if only a camera_info topic should be generated. (default: true).
- undistort True to undistort the images, false to keep the distortion. (default: true).
- process_every_nth_frame Used to temporarily down-sample the images, if it is <= 1 every frame will be processed. (default: 1).
- output_image_type Converts the output image to the specified format, set to the empty string "" to preserve the input type. See the cv_bridge tutorial for possible format strings. (default: "").
- scale Only used if output_camera_info_source is set to "auto_generated". The output focal length will be multiplied by this value. This has the effect of resizing the image by this scale factor. (default: 1.0).
- publish_tf True to publish the tf between the input and output image. If the undistortion involves changes to the rotation matrix the frame that the image is in will change. This tf gives that change. (default: true)
- output_frame The name of the frame of the output images. (default: "output_camera")
- rename_input_frame If the input frame should be renamed in the published topics and tf tree. (default: false)
- input_frame Only used if rename_input_frame is true. The name of the frame of the input images. (default: "input_camera")
- rename_radtan_plumb_bob If true the radial-tangential distortion model will be called "plumb_bob" in the output camera_info, this is needed by some ros image processing nodes. If false it will be called "radtan". (default: false).
##Input/Output Topics Many of these topics are dependent on the parameters set above and may not appear or may be renamed under some settings.
- input/image input image topic
- input/camera_info input camera info topic
- output/image output image topic
- output/camera_info output camera info topic
##Loading Camera Information from ROS Parameters:
Camera information can be loaded from ROS parameters. These parameters are typically set using . The format used by this node is compatible with the camchains generated by Kalibr. The follow steps are used when loading this information.
- A 3x3 intrinscs matrix named K is searched for. If it is found it is loaded. If it is not found a 1x4 vector named intrinsics is loaded, this contains the parameters (fx, fy, cx, cy). If neither parameters are given the node displays an error and terminates.
- A 1x2 vector named resolution is loaded which contains the parameters (width, height). Again, if not given the node displays an error and terminates.
- A 4x4 transformation matrix T is searched for. If it is found it is loaded. Otherwise it is searched for under the name T_cn_cnm1 and if found loaded. If neither are found the node continues.
- A 4x3 projection matrix P is searched for. If it is found it is loaded. If P was found but T was not, P and K are used to construct T, otherwise T is set to identity. If P was not found it is constructed from K and T.
- If an output is being loaded, the loading of parameters is completed. For input cameras the distortion properties are now loaded
- A 1xn vector D is loaded. If it is not found or is less than 5 elements long it is padded with zeros.
- A string distortion_model is loaded and converted to lower-case. If it is not found it is set to "radtan".
#stereo_info_node: A node that takes in the properties of two cameras and outputs the camera info required to rectify them so that stereo reconstruction can be performed. The rectification is performed such that only x translation is present between the cameras. The focal points are in the image centers, fx=fy and the image resolution is set to be the largest frame that contains no empty pixels. Note this node can also be run as a nodelet named image_undistort/StereoInfo
##Parameters:
- queue size The length of the queues the node uses for topics (default: 100).
- input_camera_info_from_ros_params If false the node will subscribe to a camera_info ros topic named input/camera_info to obtain the input camera parameters. If false the input camera parameters will be loaded from ros parameters. See the parameters format section for further details. (default: false).
- left_camera_namespace If the left camera parameters are loaded from ros parameters this is the namespace that will be searched. (default: "left_camera")
- right_camera_namespace If the right camera parameters are loaded from ros parameters this is the namespace that will be searched. (default: "right_camera").
- scale Only used if output_camera_info_source is set to "auto_generated". The output focal length will be multiplied by this value. This has the effect of resizing the image by this scale factor. (default: 1.0). rename_radtan_plumb_bob If true the radial-tangential distortion model will be called "plumb_bob" in the output camera_info, this is needed by some ros image processing nodes. If false it will be called "radtan". (default: false).
##Input/Output Topics Many of these topics are dependent on the parameters set above and may not appear or may be renamed under some settings.
- raw/left/image left input image topic, only needed if loading camera parameters from ros params (used for timing information)
- raw/right/image right input image topic, only needed if loading camera parameters from ros params (used for timing information)
- raw/left/camera_info left input camera info topic
- raw/right/camera_info right input camera info topic
- rect/left/camera_info left output camera info topic
- rect/right/camera_info right output camera info topic
#stereo_undistort_node: A node that takes in the images and properties of two cameras and outputs rectified stereo images with their corresponding camera parameters. The rectification is performed such that only x translation is present between the cameras. The focal points are in the image centers, fx=fy and the image resolution is set to be the largest frame that contains no empty pixels. Note this node can also be run as a nodelet named image_undistort/StereoUndistort
##Parameters:
- queue size The length of the queues the node uses for topics (default: 100).
- input_camera_info_from_ros_params If false the node will subscribe to a camera_info ros topic named input/camera_info to obtain the input camera parameters. If false the input camera parameters will be loaded from ros parameters. See the parameters format section for further details. (default: false).
- left_camera_namespace If the left camera parameters are loaded from ros parameters this is the namespace that will be searched. (default: "left_camera")
- right_camera_namespace If the right camera parameters are loaded from ros parameters this is the namespace that will be searched. (default: "right_camera").
- scale Only used if output_camera_info_source is set to "auto_generated". The output focal length will be multiplied by this value. This has the effect of resizing the image by this scale factor. (default: 1.0).
- process_every_nth_frame Used to temporarily down-sample the images, if it is <= 1 every frame will be processed. (default: 1).
- output_image_type Converts the output images to the specified format, set to the empty string "" to preserve the input type. See the cv_bridge tutorial for possible format strings. (default: "").
- scale The output focal length will be multiplied by this value. This has the effect of resizing the image by this scale factor. (default: 1.0).
- publish_tf True to publish the tf between the left input and output image. If the undistortion involves changes to the rotation matrix the frame that the image is in will change. This tf gives that change. (default: true)
- output_frame The name of the frame of the output images. (default: "left_camera_rect")
- rename_input_frame If the input frame should be renamed in the published topics and tf tree. (default: false)
- left_input_frame Only used if rename_input_frame is true. The name of the frame of the left input images. (default: "left_camera")
- right_input_frame Only used if rename_input_frame is true. The name of the frame of the right input images. (default: "right_camera") rename_radtan_plumb_bob If true the radial-tangential distortion model will be called "plumb_bob" in the output camera_info, this is needed by some ros image processing nodes. If false it will be called "radtan". (default: false).
##Input/Output Topics Many of these topics are dependent on the parameters set above and may not appear or may be renamed under some settings.
- raw/left/image left input image topic
- raw/right/image right input image topic
- raw/left/camera_info left input camera info topic
- raw/right/camera_info right input camera info topic
- rect/left/image left output image topic
- rect/right/image right output image topic
- rect/left/camera_info left output camera info topic
- rect/right/camera_info right output camera info topic
#dense_stereo_node: A node for producing dense stereo images. Internally this node simply combines 3 nodelets.
- image_undistort/StereoUndistort Used to set up the stereo system and rectify the images.
- stereo_image_proc/disparity Standard ros nodelet for generating a disparity image from a rectified stereo pair.
- stereo_image_proc/point_cloud2 Standard ros nodelet for generating a color pointcloud from an image and disparity image pair.
##Parameters:
- queue size The length of the queues the node uses for topics (default: 10).
- input_camera_info_from_ros_params If false the node will subscribe to a camera_info ros topic named input/camera_info to obtain the input camera parameters. If false the input camera parameters will be loaded from ros parameters. See the parameters format section for further details. (default: false).
- left_camera_namespace If the left camera parameters are loaded from ros parameters this is the namespace that will be searched. (default: "left_camera")
- right_camera_namespace If the right camera parameters are loaded from ros parameters this is the namespace that will be searched. (default: "right_camera").
- scale Only used if output_camera_info_source is set to "auto_generated". The output focal length will be multiplied by this value. This has the effect of resizing the image by this scale factor. (default: 1.0).
- process_every_nth_frame Used to temporarily down-sample the images, if it is <= 1 every frame will be processed. (default: 1).
- output_image_type Converts the output images to the specified format, set to the empty string "" to preserve the input type. See the cv_bridge tutorial for possible format strings. (default: "").
- scale The output focal length will be multiplied by this value. This has the effect of resizing the image by this scale factor. (default: 1.0).
- publish_tf True to publish the tf between the left input and output image. If the undistortion involves changes to the transformation matrix the frame that the image is in will change, this occurs during most image rectifications. This tf gives that change. (default: true)
- output_frame The name of the frame of the output images. (default: "left_camera_rect")
- rename_input_frame If the input frame should be renamed in the published topics and tf tree. (default: false)
- left_input_frame Only used if rename_input_frame is true. The name of the frame of the left input images. (default: "left_camera")
- right_input_frame Only used if rename_input_frame is true. The name of the frame of the right input images. (default: "right_camera") rename_radtan_plumb_bob If true the radial-tangential distortion model will be called "plumb_bob" in the output camera_info, this is needed by some ros image processing nodes. If false it will be called "radtan". (default: false).
###Note: All of the standard parameters of stereo_image_proc/disparity and stereo_image_proc/point_cloud2 are also accessible and settable. These parameters appear in the ~/disparity and ~/point_cloud2 namespaces respectively. Also note that unlike the standard behavior, this node sets approximate_sync to true by default. See the stereo_image_proc page for up to date parameters and default values.
##Input/Output Topics Many of these topics are dependent on the parameters set above and may not appear or may be renamed under some settings.
- raw/left/image left input image topic
- raw/right/image right input image topic
- raw/left/camera_info left input camera info topic
- raw/right/camera_info right input camera info topic
- rect/left/image left output rectified image topic
- rect/right/image right output rectified image topic
- rect/left/camera_info left output camera info topic
- rect/right/camera_info right output camera info topic
- disparity output disparity image topic
- points2 output pointcloud topic
- dense_stereo_disparity/set_parameters service for setting the stereo image generation properties. See stereo_image_proc for details.