Convert between NV12 and RGB888 with qrb_ros_colorspace_convert

The qrb_ros_colorspace_convert sample application converts between NV12 and RGB888 formats. Qualcomm’s smart devices, such as the Qualcomm Dragonwing^TM IQ-9075 Evaluation Kit, use NV12 as the default image color space conversion format. However, most ROS 2 image processing nodes expect RGB888. Use qrb_ros_colorspace_convert to bridge the two. The qrb_ros_colorspace_convert sample application implements the following:

Converts NV12 to RGB888 through a ROS node API.
Converts RGB888 to NV12 through a ROS node API.
Accepts and returns a dmabuf file descriptor, so buffers are shared rather than copied.
Sends and receives images over QRB ROS transport.
Runs the conversion on the GPU through OpenGL ES.

Pipeline flow for `qrb_ros_colorspace_convert`

Figure: Pipeline flow for qrb_ros_colorspace_convert

ROS nodes used in the `qrb_ros_colorspace_convert` pipeline

ROS Node	Description
`custom_ros_node`	`custom_ros_node` is the ROS package that publishes the input image information to the colorspace_convert_node. You should implement this ROS2 node.
`colorspace_convert_node`	`colorspace_convert_node` is a ROS package to convert color space between NV12 and RGB888.

ROS topics used in the `qrb_ros_colorspace_convert` pipeline

ROS topic	Message type	Published/Subscribed by	Description
`/image_raw`	`sensor_msgs::msg::Image`	Subscribes to images from other nodes	The input NV12/RGB888 encoded image.
`/image`	`sensor_msgs::msg::Image`	Published by `colorspace_convert_node`	Publishes the converted NV12/RGB888 encoded image.

Prerequisites

You have Set up the device according to Set up the environment for running sample applications.
The custom_ros_node is ready.
You have connected the device to the display monitor.

Run out-of-the-box `qrb_ros_colorspace_convert`

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Set up the runtime environment

Value range of ROS_DOMAIN_ID: [0, 232]

SSH Session

# Set up the runtime environment
source /usr/share/qirp-setup.sh
export ROS_DOMAIN_ID=xx
# Set up the Weston environment
export XDG_RUNTIME_DIR=/dev/socket/weston/
mkdir -p $XDG_RUNTIME_DIR
export WAYLAND_DISPLAY=wayland-1
# Set up the shared memory
export FASTRTPS_DEFAULT_PROFILES_FILE=/usr/ros/jazzy/share/qrb_ros_colorspace_convert/config/large_message_profile.xml

Run the sample qrb_ros_colorspace_convert

SSH Session

# To convert color space from NV12 to RGB888, run the following command
ros2 launch qrb_ros_colorspace_convert colorspace_convert.launch.py 'conversion_type:=nv12_to_rgb8' 'latency_fps_test:=False'
# To convert color space from RGB888 to NV12, run the following command
ros2 launch qrb_ros_colorspace_convert colorspace_convert.launch.py 'conversion_type:=rgb8_to_nv12' 'latency_fps_test:=False'

ResultTo confirm the conversion, compare the encoding of the input and output topics:

SSH Session

ros2 topic echo /image_raw | grep "encoding"
ros2 topic echo /image | grep "encoding"

The two commands report different encodings — one NV12 and one RGB8 — in the direction you selected.

​Pipeline flow for qrb_ros_colorspace_convert

​ROS nodes used in the qrb_ros_colorspace_convert pipeline

​ROS topics used in the qrb_ros_colorspace_convert pipeline

​Prerequisites

​Run out-of-the-box qrb_ros_colorspace_convert

Pipeline flow for `qrb_ros_colorspace_convert`

ROS nodes used in the `qrb_ros_colorspace_convert` pipeline

ROS topics used in the `qrb_ros_colorspace_convert` pipeline

Prerequisites

Run out-of-the-box `qrb_ros_colorspace_convert`