Zed 4.0.6 - Broken python library

With https://stereolabs.sfo2.cdn.digitaloceanspaces.com/zedsdk/4.0/ZED_SDK_Ubuntu20_cuda11.8_v4.0.6.zstd.run pyzed fails to import. This previously worked on 4.0.6, but no longer does.

> python
Python 3.10.13 
>>> import pyzed.sl as sl
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: /...python3.10/site-packages/pyzed/sl.cpython-310-x86_64-linux-gnu.so: undefined symbol: _ZN2sl6Camera19getRegionOfInterestERNS_3MatENS_10ResolutionE

This happens even after re-running

> python /usr/local/zed/get_python_api.py

This is fixed in 4.0.7, but that neural depth model performs worse.

This is because get_python_api.py returns the latest python module, which is now 4.0.8. The compatibility was not there between 4.0.7 and 4.0.6 because the API changed within the same minor version. We will avoid that in future patches, it was because of the early access. Sorry again.
If you still want to use 4.0.6 and the python module, you can build it yourself from the repo GitHub - stereolabs/zed-python-api: Python API for the ZED SDK. It’s actually quite easy.

It’s very suprising that you found difference between NEURAL version 4.0.6 and 4.0.7 since it did not change. Is it still the case with 4.0.8 ? Can you send a SVO so that we can investigate ?

I can still get an SVO if needed, but the changelog did say the network changed. 4.0.7 Confidence Ranges Changed - #4 by Myzhar

The issue now is in scenes that would’ve previously had points almost everywhere, we get large patches of completely empty space when using low confidence_thresholds

Indeed, the confidence ranges was retuned - however if you modify the confidence, you can get the same quality as you had before. It’s just that low confidences are now really low, whereas they were still quite high before.

The issue is it’s really hard to know what the mapping from old confidence values to new confidence values is. The changelog and docs provided no guidance on this issue. If you can provide more guidance now it’d be very helpful

Of course ! Can you tell me what your old confidence value was ?

It was 0. On 4.0.7, 0 returns no values.

Can you try with the value 1 ?

I have tried many confidence values. None consistently perform in a similar manner. Do you have the python whl for 4.0.6? I would like to manually install it. The depth model 4.0.7+ is not viable.

I’m also ok with building it from source https://github.com/stereolabs/zed-python-api/tree/master/src if you can direct me to the correct commit.

Really sorry about this. I can reproduce your behavior a little:

This two images are taken from 4.0.5 and 4.0.8. The one with more black is 4.0.6 at 0%, the other is 4.0.8 at 1%. I guess the confidence is still too high for you ? If you can send a SVO file, it can really help us understand the issue better. I thought that you actually had less points than before, but in my tests I get more.

What you can try is to remove the NEURAL model from /usr/local/zed/resources, to force a reoptimizations. You’ll be sure you have a fresh installation.

In the meantime, here is the python wrapper for 4.0.6.
pyzed.zip (929.6 KB)

Do you have the 4.0.6 wheel file? Alternatively, how do I convert the zip you sent to a wheel.

I was able to build the 4.0.8 egg from source, but didn’t see how to produce a wheel file from that. The building also failed for me for sdk versions <4.0.8 on any of the 5 most recent commits of the python-sdk repo.

I observed a similar change in the number of points between 4.0.6 and 4.0.7. In almost every case there were more points in 4.0.7+ with a confidence threshold of 1% compared to <4.0.7 with a confidence of 0. However, in <5% of cases the 4.0.7+ model with confidences ranging between (1 and 5) would catastrophically return no points for about 1/4 of the entire scene. These scenes were all within the min/max depth runtime parameters and similar to the scenes we had successfully operated in with <4.0.7.

I’d like to send you an SVO, but don’t have any available and struggle to reproduce this issue whenever SVO recording is an option. Is there a way to use the SDK normally/live and also record SVOs?

Also if you have an email/slack/discord we could use to communicate I can share more details than I am comfortable doing on this forum.

Hi again,

You can just replace the files I sent you in the repo from github (latest vesion). Then do what is in the readme.
Alternatively, send me you platform and python version and I will build you it. I guess, Python3.10, Ubuntu20 ? If that’s the case, here it is:
pyzed-4.0-cp310-cp310-linux_x86_64.whl (622.9 KB)

Thank you for the wheel. I’ll work on getting SVO files, but it will take a while

1 Like

Hi, I tried again to build the wheels for python 3.11, but still ran into tons of issues. Could you compile a ubuntu 20, python 3.11 wheel for me? It would be incredibly helpful. Thank you

Also is there a docker container you’d recommend for compiling things?

I spent some more time on this. I was able to build the wheel for 3.11 ubuntu 20 with 4.0.8, but not with the files you sent for 4.0.6. To get it to work for 4.0.8 I

  1. Built off stereolabs/zed:4.0-devel-cuda11.8-ubuntu20.04 docker image with a python3.11-dev virtual environment
  2. Installed the 4.0.6 SDK
  3. Swapped in the files you sent
  4. Installed all required python packages
  5. Ran python setup.py bdist_wheel
    When running setup.py I get a bunch of errors like

pyzed/sl.pyx:10670:89: 'c_REFERENCE_FRAME' is not a type identifier

Error compiling Cython file:
    # \param reference_frame: Defines the reference from which you want the pose to be expressed. Default : \ref REFERENCE_FRAME "REFERENCE_FRAME.WORLD".
    # \param uuid: If set to a sender serial number (different from 0), this will retrieve position projected on the requested camera if \ref position_type is equal to \ref POSITION_TYPE "POSITION_TYPE.FUSION" or raw sender position if \ref position_type is equal to \ref POSITION_TYPE "POSITION_TYPE.RAW".
    # \param position_type: Select if the position should the fused position re-projected in the camera with uuid or if the position should be the raw position (without fusion) of camera with uui.
    # \return POSITIONAL_TRACKING_STATE is the current state of the tracking process.
    def get_position(self, camera_pose : Pose, reference_frame : REFERENCE_FRAME = REFERENCE_FRAME.WORLD, uuid: CameraIdentifier = CameraIdentifier(), position_type : POSITION_TYPE = POSITION_TYPE.FUSION):
        return POSITIONAL_TRACKING_STATE(<int>self.fusion.getPosition(camera_pose.pose, <c_REFERENCE_FRAME>(<int>reference_frame.value), uuid.cameraIdentifier, <c_POSITION_TYPE>(<int>position_type.value)))

pyzed/sl.pyx:10670:161: 'c_POSITION_TYPE' is not a type identifier

Error compiling Cython file:
    # \return sl.Transform is the calibration found between VIO and GNSS during calibration process.
    def get_geo_tracking_calibration(self) -> Transform:
        # cdef c_Transform tmp
        tf_out = Transform()
        tmp = <c_Transform>(self.fusion.getGeoTrackingCalibration())

pyzed/sl.pyx:10731:15: 'c_Transform' is not a type identifier

Error compiling Cython file:
    # \return sl.Transform is the calibration found between VIO and GNSS during calibration process.
    def get_geo_tracking_calibration(self) -> Transform:
        # cdef c_Transform tmp
        tf_out = Transform()
        tmp = <c_Transform>(self.fusion.getGeoTrackingCalibration())

pyzed/sl.pyx:10731:14: Casting temporary Python object to non-numeric non-Python type
Traceback (most recent call last):
  File "/root/zed-python-api/src/setup.py", line 194, in <module>
    extList = cythonize(extension, compiler_directives=cython_directives)
  File "/root/311-env/lib/python3.11/site-packages/Cython/Build/Dependencies.py", line 1154, in cythonize
  File "/root/311-env/lib/python3.11/site-packages/Cython/Build/Dependencies.py", line 1321, in cythonize_one
    raise CompileError(None, pyx_file)
Cython.Compiler.Errors.CompileError: pyzed/sl.pyx

Any suggestions on how to build it properly?

Hi @robots

The files @alassagne send you should not be compatible with Cython 3.0 (since the ZED SDK 4.0.6 is not).

You can either:

  • downgrade Cython to 0.29 and use this setup.py (6.6 KB)


  • try to update sl.pyx to be compatible with Cython 3.0 (it might be simple as replacing
    from sl_c cimport ( String, to_str, Camera as c_Camera, ERROR_CODE as c_ERROR_CODE, toString
    from .sl_c cimport ( String, to_str, Camera as c_Camera, ERROR_CODE as c_ERROR_CODE, toString
    if I remember correctly)