How to get raw data in uint16 format

[gustn6591]

Hello, I managed to get a grayscale image of (480,640) through the code below.

cap_depth = cv2.VideoCapture("rtsp://admin:admin@192.168.1.10/depth", cv2.CAP_GSTREAMER)
while(True):
ret2, frame_depth = cap_depth.read()
cv2.namedWindow('kinova_depth', cv2.WINDOW_AUTOSIZE)
cv2.imshow('kinova_depth',frame_depth)
if cv2.waitKey(20) & 0xFF == ord('q'):
break
cap_depth.release()
cv2.destroyAllWindows()

However, the output image was in uint8 format ranging from 0 to 255, and accurate depth information could not be obtained.
I was able to get a value similar to uint16 through (pixel/255)*65535, but a lot of errors occurred because I had already brought the value of uint8.
I did a lot of searching and found several ways, but I didn't know the exact way to get depth data in uint16 format from realsense(D410) attached to gen3.
I know that using ros_rgbd.launch I can get the point cloud, so I'm pretty sure I can get uint16's information, but I don't know how.
I want to know how to get depth information from ros_kortex_vision repo or an example, so I leave a question.

Thank you

[felixmaisonneuve]

Hi @gustn6591,

Depth stream is in 16bit encoding and we pass GRAY16_LE encoding to Gstreamer to get this point cloud.

ros_kortex_vision/src/vision.cpp

Lines 62 to 66 in cd49bab

	else if (camera_type == "depth")
	{
	camera_type_ = CameraTypes::Depth;
	image_encoding_ = sensor_msgs::image_encodings::TYPE_16UC1;
	}

ros_kortex_vision/src/vision.cpp

Lines 120 to 123 in cd49bab

	if (image_encoding_ == sensor_msgs::image_encodings::TYPE_16UC1)
	{
	gst_encoding = "GRAY16_LE";
	}

The color stream however is in RGB8 encoding

ros_kortex_vision/src/vision.cpp

Lines 124 to 127 in cd49bab

	else if (image_encoding_ == sensor_msgs::image_encodings::RGB8)
	{
	gst_encoding = "RGB";
	}

if you launch the kinova_vision_rgbd.launch file, you will only have access to both color and depth stream, so make sure you are using the correct depth stream and not the color stream.

Best,
Felix