Depth data by kinect v2

[Abdulrahman Alshanoon]

Hi,

I am using Linux, Ubuntu 16.04, and Kinect v2. I want to estimate the distance between the object and kinect v2.
I know that from the depth image we clearly notice that the depth info of object is based on intensity of gray color [the most dense one is the closest to the kinect v2]. But I want I obtain the range of this gray color.

I tried these :-

roslaunch kinect2_bridge kinect2_bridge.launch
rostopic echo /kinect2/sd/image_depth

I get a lot of numbers and I do not know how to read it or convert it to millimeter or meter.

Any one can help ?????????????????????