Hi,
I have a zed2i camera and tested it with both sdk and ros2 wrapper.
I found one issue regarding zed.get_camera_information().camera_configuration.calibration_parameters.stereo_transform is different from ros2 tf messages.
When I check the stereo_transform with zed sdk, it returns (0.11982602626085281, 0.0, 0.0). But, when I check it with lookup_transform in ros2, I got geometry_msgs.msg.Transform(translation=geometry_msgs.msg.Vector3(x=0.12, y=-3.469446951953614e-17, z=-6.245004513516506e-17), rotation=geometry_msgs.msg.Quaternion(x=0.0, y=0.0, z=0.0, w=1.0)). I know the difference is very small but I would like to know why there is a difference and what value I can trust.
Here, I attached my scripts.
with zed sdk
import pyzed.sl as sl
def main():
zed = sl.Camera()
init_params = sl.InitParameters()
init_params.camera_resolution = sl.RESOLUTION.HD2K
init_params.camera_fps = 30
init_params.coordinate_units = sl.UNIT.METER
# Open the camera
err = zed.open(init_params)
if err != sl.ERROR_CODE.SUCCESS:
print("Camera Open : " + repr(err) + ". Exit program.")
exit()
calibration_params = zed.get_camera_information().camera_configuration.calibration_parameters
# left to right camera translation
print(calibration_params.stereo_transform.get_translation().get()[0])
print(calibration_params.stereo_transform.get_translation().get()[1])
print(calibration_params.stereo_transform.get_translation().get()[2])
zed.close()
if __name__ == "__main__":
main()
with ros2
import rclpy
from rclpy.node import Node
from tf2_ros import Buffer, TransformListener
class TFInspector(Node):
def __init__(self):
super().__init__('tf_inspector')
self.tf_buffer = Buffer()
self.tf_listener = TransformListener(self.tf_buffer, self)
self.timer = self.create_timer(1.0, self.lookup)
def lookup(self):
try:
tf = self.tf_buffer.lookup_transform(
'zed_left_camera_optical_frame',
'zed_right_camera_optical_frame',
rclpy.time.Time()
)
self.get_logger().info(f"Transform: {tf.transform}")
except Exception as e:
self.get_logger().warn(f"TF lookup failed: {e}")
def main(args=None):
rclpy.init()
node = TFInspector()
rclpy.spin(node)
