How to convert uint8 data captured by Depth to the correct 'mono16'？

[wenmingxiaohuo]

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Required Info
Camera Model	{ R200 / F200 / SR300 / ZR300 / D400 }
Firmware Version	(Open RealSense Viewer --> Click info)
Operating System & Version	{Win (8.1/10) / Linux (Ubuntu 14/16/17) / MacOS
Kernel Version (Linux Only)	(e.g. 4.14.13)
Platform	PC/Raspberry Pi/ NVIDIA Jetson / etc..
SDK Version	{ legacy / 2.. }
Language	{C/C#/labview/nodejs/opencv/pcl/python/unity }
Segment	{Robot/Smartphone/VR/AR/others }

Issue Description

<Describe your issue / question / feature request / etc..>

[MartyG-RealSense]

Hi @wenmingxiaohuo RealSense depth data is not 8-bit. It is 16-bit uint16_t.

[wenmingxiaohuo]

filename='D:\RecordData_D435\20241125_111919.bag'; % validateattributes(filename, {'char','string'}, {'scalartext', 'nonempty'}, '', 'filename', 1); bag=rosbag(filename); mes=select(bag,'Topic','/device_0/sensor_0/Depth_0/image/data'); poseStructs = readMessages(mes, 'DataFormat', 'struct'); %
Getting information from the depth sensor，

The Data is unit8 but the decoding method is mono16.

[wenmingxiaohuo]

Thanks for the quick answer, also if you use pipe to get the data you will get the uint16 data
`for i = 1:5
fs = pipe.wait_for_frames();
end
depth = fs.get_depth_frame();
dwidth = depth.get_width();
dheight = depth.get_height();
units = depth.get_units();
Temp=depth.get_data();
depthdata = (reshape(depth.get_data(),dwidth,dheight))';
depthdata = double(depthdata)*units;

[MartyG-RealSense]

You are very welcome. Thanks for sharing your code!

[wenmingxiaohuo]

Thanks, but I'm still a little confused.
I want to convert 814080 of uint8 to 407040 of uint16, what should I do?

[MartyG-RealSense]

Was the bag file recorded in ROS and you are attempting to read it using the librealsense SDK, please? If it is a ROS bag then it will be difficult to use with librealsense because there are differences between the rosbag format of ROS and librealsense's SDK-bag format, as advised at #3020 (comment)

8-bit to 16-bit conversion is not usually something that is done with RealSense depth data, but the non-RealSense link below might provide some ideas about how to do it.

https://stackoverflow.com/questions/52183191/convert-uint8-t-array-to-uint16-t

[wenmingxiaohuo]

Ok thanks for the answer, I see what you mean. Also in response to your reply there is a small question, 'D:\RecordData_D435\20241125_111919.bag' is the data captured using the D435, how can I tell if this bag file is a ROG bag file?

[wenmingxiaohuo]

Sorry, I have other things to take care of, so please just leave a message at your leisure. Thank you for every answer, bye!

[MartyG-RealSense]

A quick way to test whether a bag file might be a ROS bag is to drag and drop the file into the center panel of the RealSense Viewer tool if you have access to that tool. If there is an error message instead of the bag starting to play automatically then there is a good chance that it is a rosbag instead of an SDK-bag.

[wenmingxiaohuo]

I'd like to reiterate my question.
Recorded packets show depth data is a mono16 form, that is, it should be a layer of uint16 data, however, the actual data points are 1280 * 720 twice the amount, and the form is uint8, it should be reasonably to 2 for a group to uint16 format, how to realize it?

[MartyG-RealSense]

I do not have knowledge about this particular subject. It may be worth looking at the librealsense SDK's /sensor_msgs/image_encodings.h source code file and doing a search on the page for the word mono16 to find relevant references in the code.

https://github.com/IntelRealSense/librealsense/blob/master/third-party/realsense-file/rosbag/msgs/sensor_msgs/image_encodings.h

[MartyG-RealSense]

Hi @wenmingxiaohuo Do you require further assistance with this case, please? Thanks!